I've been preaching this for years about the LS engines. It's almost always the rear engine cover gasket! There's also a porosity issue with the OEM rear covers where they will weep oil through the metal cover. People will change the oil pan gasket and the leak will continue. They'll then replace the rear main seal and the leak will continue. They'll finally replace the rear cover and gasket and the problem is solved. The camshaft position sensor is not in the back top like older LS engines but that's also a common leak point due to the o-ring going bad over time.
I’ve been doing the professionally for quite a few years. So far I’ve never seen a rear main seal fail on these engines. It was always the rubber portion of the two piece gasket flattened. The cure is to get the whole rear cover! I had only one come back and it was wicking oil around one or two cover bolts. Added silicone th these bolts. Was cured! 2:25 2:25 2:25 😅😊 2:25 😅😅😊😅😊😊😅😅 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 😊😅 2:25 2:25 😅😅 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 😊
@@DannyDisharoonWhen you say "rear cover" are you referring to the crankcase cover? I'm facing a similar problem on my vehicle and I'm struggling to find the plate he's talking about on a parts list
I watch all your vids here in England , ive been sleeping on the streets an in car parks but i just got a flat (i bed appartment ). To anyone in a similar situation, keep the hope bro or sis keep strong in your mindset, if you like god what the hell it cant hurt anything . Just keep yourself as personally clean as possible an your mind strong .if you need a chat I’m here for you all I’m NO guru but ive don it in England . Sorry for stealing your thread 😮😮
We've had about 35 of the 6.0 engines in our fleet I've replaced the rear main and plate gasket in only 2 of them and they both had 300,000 plus on them. Very durable engines.
I had a 1998 express van and the timing chain cover just split open. We bought it brand new . All decked out VCR, TV, headphone jacks fort. Regency . Anyway to change the cover I had to change oil pan gasket and timing gasket. Bottom of timing cover a rubber gasket was both covers gasket.
You wouldn't think that the gasket on a blank plate to cover the attachement for the oil cooler on engines that don't have the auxiliary oil cooler would be that hard a thing to get right, but they leak like mad. I generally pull the driver's side front wheel and reach in with an extension to remove the bolts with the least grief.
I have the 5.7 litre Chevrolet LS1 V8 engine fitted into a VY Commodore sedan here in Australia & I replaced the old olive coloured rear main oil seal which was 13 millimetres thick with a 10 millimetre thick black Felpro rear main oil seal back in 2016 & I also replaced the seal carrier gasket as well because it's a lot easier to fit the rear main oil seal when the carrier is out of car since it's harder to replace it while you're lying underneath the car at home. The old seal carriers is deeper so I was very careful regarding how far to push it into the seal carrier. I have replaced the oil pan gasket because I was driving over rough road in a Commodore meaning that the oil pan bolts kind of vibrated loose !
Crankcase ventilation build up can cause havoc on leaks. Not saying it's a issue here but it sure is the first thing i go to with leaks. Replace the PCV valve most people overlook and forget about then check for leaks see what happens. A bad PVC valve will indeed reveal the weakest link on engine seals and gaskets... I've seen it happen many times.
If the PCV hose is disconnected from the intake would that cause an oil leak? The guy who built my truck disconnected it from The intake and said it’ll run better but it’s been leaking little drops of oil from the top driver side engine and down to the oil filter and to the tranny
@jonathandeleon5588 in no way would disconnecting the PVC hose be better. For one it causes crank case pressures to rise too high. Second, if the hose off the intake isn't plugged with something, that's a bad vacuum leak for the engine reducing power, idling bad, and consume too much fuel.
@@garyr7027 yea he plugged the intake PCV hose with like a little plug but the hose by the valve cover gasket is just hanging he told me it runs better since I have the truck cammed but I been having oil leaks like little drops idk if that could be a cause or not
@@jonathandeleon5588 tell him to put that pcv valve back like it was. Cammed or not that doesn't matter, a engine still needs crank case pressure relief or it builds up pressure from heat and blow by from the piston rings. Cams has nothing to do with piston ring blow by, which is normal even for a new engine. PCV valves aren't there just for looks, there's a good reason for them being there.
Flying sparks garage has a good video explaining that plate and rear main seal. If anyone is curious to what it looks like. I believe it's the video where they're putting the transmission back in to a Corvette. Good info as always Kenny nice wrenching.
Oil leaks are a pain, especially if the transmission has to come out. $$$ It can be deceiving sometimes, that what appears to be a huge leak really isn't. A few drops of oil or trans fluid looks like a lake on concrete. That one is pretty significant though, since you cleaned it and all, you can tell it's pretty bad. At least if you pull the trans, you will be able to change the seals on the engine and trans, and that gasket you were talking about.
My issue started when I changed the oil on my 4.3 v6 2000 chevy pickup. After changing the oil I had big oil spots on my driveway . I suspected the crush gasket on my drain plug, so 20 miles later I drained my oil to replace the crush gasket on the drain plug, GOT IT.. Well I continued to have big and bigger oil spots. Shoot either wrong oil filter or double gaskets on the oil filter. 22 miles later I got a new oil filter and I changed it, NO double filter gaskets.. I thought maybe the oil filter was defective. Either way it should stop leaking. NO , still having bigger oil spots. Basically it was the oil pressure sending unit leaking. I replaced it and NO more oil leaks. Regardless why did it start leaking after I changed the oil ? Because that’s the way Murphys law works. I thought that was going to be the problem on Kenny’s video.
When I was a young teen just starting to mess with cars, changing oil, tires, simple things, I changed the oil on my dad's Ford and then the light was on all the time. It blew my mind. In those days most cars just had idiot light for oil pressure which usually didn't come on until the pressure was almost zero, Fords would come on under about 10 pounds The pressure was low but enough to feed the engine, not enough to turn out the light. The way it decided to start acting like that right after I changed the oil was not what this young kid needed.
i've done these a few times. i pulled the engine replaced the rear plate comes with seal when it was easy to repair the exhaust leak at the left rear manifold and the list of all the other leaks . crank sensor oil filter housing oil cooler hoses ps hoses
On my 2000 Saturn 3.0 I have the similar issue. Of course 3 shops gave me all different diagnosis, and ALL were wrong. Valve covers, oil filter housing and oil cooler line gasket. It leaks in that same area between the engine and trans. I had the engine installed 2 years ago, and after about 6 months started the leak. It used to leak on the cardboard on my garage floor, but has since stopped in the past 6 months, but still leaks while running, because it still is wet and runs back along the trans and blows back on the exhaust pipe bend and smokes when the lights are on, and I can smell oil burning. I thought it was the main seal, but not sure what covers there are on a 3.0 around there. I put some 205 RE sealant in it and see what it does. The pan usually drains in about 3000 miles and I have to add a quart and a half between changes with synthetic oil. We'll see if that stops it. I'd hate to spend $800 to pull the trans to replace a main seal. I'm too old to mess with that kinda stuff myself anymore. Lol.
Thanks, a customer of mine let his son replace rear main on his Silverado now I have to figure out why transmission doesn't work. I had been looking for that leak prior to his son making more work for me on trans now.
Tip: LS motors leak oil easily if the pvc system isn’t correctly working and set up right. LS motors leak oil from flywheel bolt holes on the crank flange when the bolts haven’t been sealed. Both of these conditions are usually found on hot rodded motors.
I rebuild transmissions and when ever I have the transmission off one of these engines, I always put my finger tip into the well where the cam sensor is located and have found many to be leaking, also there is a pipe plug where that block off plate is on the oil pan and it will leak and it cant be removed as installed, but when the transmission is out it can be checked for tightness or resealed.
Does that plug sit right behind the starter? I got a 4.8 that looks like it's leaking out of a bolt (where crank sensor would be on other models) right above oil pan gasket and just behind starter
@@Father_Adrian No, the plug I'm speaking of is on the other side "drivers side" it is there to plug a drilled passage for the oil cooler circuit in the oil pan. Leaking oil travels by two means, gravity and wind, so always remember that where its dripping from is not necessarily the source of the leak. Put sealer on the threads or check the O ring on the sensor or plug if it doesn't have a sensor where it could have one. Good luck, and be the oil leaking. Where would you go?
@Wrenching With Kenny This helps me a lot. I have a 2008 Escalade EXT, basically the same truck as this, But mine is the 6.2 with 4WD. I have had a minor oil leak for a few years, about 4-5 drops on the driveway over night in addition to whatever it leaks out while driving. The truck has about 110K miles which is low for a 2008. But after I did an oil change last week the leak got about 10 times worse. Constant drip while running and once parked it will leave a 6" diameter puddle on a smooth surface like concrete. I'm at the point of putting my oil change catch pan under the truck instead of a sheet of cardboard. I assumed it was the RMS so I put in some blue Devil RMS additive. The leak has slowed, now down to under a quart a day on a very light 30 mile a day commute and seems to get better every day. But last night I cleaned everything then started the truck and got under with lights and I see now the oil is running down both sides of the back of the oil pan and collecting around the trans inspection port. Inside the trans inspection port it looked just like in this video, a little wet but not nearly enough to explain the amount of oil I'm losing. I'm thinking oil pan or oil pressure sensor as it's coming down both sides of the back of the engine. I still need to look at the back of the engine above the oil pan. Thoughts?
07 Escalade with an oil leak here. Similar situation as yours. Oil coming down both sides of the top of the trans is what it seemed like. Changed my valley cover gasket, valve cover gaskets, oil pressure sensor and intake manifold gaskets while I was in there. I’m willing to bet that the leak remaining is either this plate in the video or RMS. Gonna try to solve it this week
I fixed a bad oil leak on a 07 Denali, that was very difficult to pinpoint because it would drip down above the transmission bell housing, it ended up being the valley pan gasket.
When I had wetness near the rear main on my Chev 5.3 a couple of years ago, I assumed a rear main and decided to ignore it. It was a stupid mistake. Later when the oil pressure sensor finally failed I discovered that the oil was coming from the sensor up top. Doh!
Really? Do you know for what year and what the sensor is called? Also where about is it located? I'm scratching my head on a oil leak as well..99 Silverado 5.3.
Mr.Good Wrench , Leaks out (the Main Concern) and no second guessing! Too many part's replacers out there! Your videos are a learning tool with visual!
My 2006 Tahoe 4.8 is leaking by the starter like in your video. Also at the end of video that gasket you pointed to above oil filter mine is wet all around there with oil also. I'm going to clean it like you did and watch it idle to determine where it is leaking. Thanks for the video showing this.
I think your diagnosis of the seal plate is correct on this one. However, I've seen those CKP sensors leak a few times. The o-ring is an odd size so you have to get a new CKP to fix it.
Awesome video! I thought my 2011 suburban Ltz was just consuming a lot of oil…looks like I gotta take it in and have the rear main, the plate you were speaking of and the oil pan gasket replaced….not to mention my oil cooler lines…
I have a 2006 Silverado 5.3 Had rear main seal replaced about a year and a half ago along with oil pan gasket and valve covers. Still had the leak. Had to have some work done a few months ago. Asked them to check the leak. They said it was valve cover gaskets and they were replaced again along with something else underneath ( don't remember what). Stoll have a leak but not as bad.
@@edsyphan3425 - This was 2 different places. I think both places actually got some of it bit there us something they missed and may be this plate the video is about.
I replaced rear main front main and timing cover,, then a few days ago I done the sump just to find out it was the crank position sensor that’s about the starter motor 🤦🏻
Have this problem with my03 Tahoe. Not looking forward to pulling tranny. I’ll replace rear seal oil sensor and cover plate while it’s accessible. Some fun!
Great video. I suspect that's what happened to my 2008. Also, what is the technical name for the oil cooler gasket though pointed out at the end. I might as well replace that while doing the job.
I have a 2005 Yukon 5.3L 4x4. Looks exactly the same. I may have a very slow rear main leak. I just got it and am watching it now after a fresh oil change. Has 216,000 miles on it. Seems to run great though. 3 questions: 1. Was there a cover on your inspection hole that shows the bottom of the flex plate? Mine does not have a cover of any type. I can see the bottom of the flex plate. 2. I have a pair of ramps that raises vehicles back or front tires by about 12". Would that be helpful to use for this job? 3. So the rear seal has two parts? A shaft seal, plus a shaft seal cover gasket? Does the cover seal just keep dust out? It doesn't have a gasket across the bottom of it, does it?
Correct. There is a radial oil seal and a rubber seal for the cover plate. The bottom of the cover plate is what the oil pan seals against with it's own rubber seal. It's important to align the plate properly so that the seal bore is concentric to the crankshaft and the bottom of the cover is perfectly horizontal. The alignment tools are cheap and can be found on Amazon or eBay. You install the cover with the alignment tool inserted where the seal would be, and then tighten it down and install the seal last. There's also an alignment plate for keeping the bottom horizontal in case the oil pan isn't installed, which is the only way I've personally done it. Better replace the oil pressure sending unit while you're under there, as well as any sensor o-rings. To be honest, it may be best to have the oil pan off, and to change the pick-up tube o-ring, but that's quite a bit more involved, especially with a 4x4. Just my 2 cents.
@ryanmcrae3593 When the cover gasket is not done right, where is the oil coming from that leaks from the bottom of it? If the oil pan seal is good, crank rear seal is good, but the cover plate is not sealed good, where does the oil leak out of?
@@thesetruths1404 I honestly don't have enough experience with the LS engines to be able to tell you for sure. Maybe someone with more knowledge of these issues will chime in. I'd say the oil would most likely be coming from where the cover mates to the oil pan.
I thought that I had a leaking oil pan gasket on my truck but it turned out to be a leaking gasket on the driver’s side valve cover. I ignored the leak for about 10 years until it got so bad that it was starting to leak on the exhaust manifold. Luckily, the gasket wasn’t that hard to change.
Thank you for this. I'm so torn on what to do with next with my 08 5.3 Chevy 1500. She leaks about 2qts oil every 5k miles, and has done this for about 25k miles. I replaced the oil pan gasket, and it still leaks. It was stupid of me because it will only leak after it's been driven, so no duh it wasn't the oil pan gasket. After watching your video, I don't know whether to replace the rear main seal, oil cooler, or the rear cover and gasket. DANGIT.
I'm very curious about the oil cooler gasket that you said.my truck does not have one but it does have those two bolts and gasket. I've changed the oil pan and gasket and still leaks .took it to get an alignment and the technician said it was a engine seal but didn't show me...99 Silverado 1500 5.3 2WD.
ya some shop changed this on a 06 5.3 and its leaking worse now 40k miles later than it did when it had like 140k. Sucks removing a transmission on jack stands
Glad to know that is there I have to replace the transmission on my '01 Suburban so I'll go ahead and replace that seeing I have around 250k on the odometer
Whoa, that is a bunch of miles on one of those, you may want to do like Kenny does and just find a replacement out of a wrecked vehicle that has 70k miles or less, engine and transmission. Just a thought.
@@jeremyself2156 Good luck to you, change anything you can that's normally hard to do while you have it apart. Rear seals, gaskets, oil sending unit and O2 sensors, well you get the picture, I hope it all goes well.
Could the leak be caused by incorrect cleaning/sealing of the rear corners of the oil pan gasket, when it was replaced? (Where the oil pan gasket crosses the end of the rear cover plate and its gasket). J
Good Morning Kenny..! I’m not so sure about an Avalanche … or a truck named after an avalanche..and I am a Chevy Man .. can’t wait to see how you fix it ..good luck 🍀
My 4.8 is doing the same thing. Curious how much a reputable mechanic would charge to fix this. I usually tackle everything myself but pulling the transmission isn't fun.
For the longest time I thought I had a rear main leak. Then I did head gaskets and found that all the oil I thought was coming from the rear main, was actually coming down from the back of the valve covers.
I have leak btwn the engine and trans on a 6.0 that occurs as it sits on a lift through winter storage. Is there oil trapped behind this plate that would drain out after the car has been sitting for an extended period of not running. All the oil should be in the sump by this point and not above the crank seal
Another way to find the oil leak is put that fluorescent dye stuff in the oil and use a scanner/viewer to see exactly where the oil leak is coming from.
Good video! I was just notified by my dealership that I have a rear seal and plate leak. I will trouble shoot this myself but, what angers me so is with this dealership, every time I take mine or my wife’s vehicle in it’s something else. I don’t wanna say it’s sabotage but, every time they point out an issue I’ve gone in and repaired it myself. At seventy five, my days doing this are becoming harder. If they’re doing this to me, I can’t imagine what they’re pulling on the neophyte that has no sense of engines or cars. I take really good care of my vehicles but, I’ve had it with this outfit.
I have a 2002 Blazer with less than 70k on the 4.3 and it leaks inconsistent,start up more and move out of shop park leaks about an 8 inch circle of oil on concrete. Drive for hours park on concrete, maybe 2-3 small drips ???? Not filter,rear main had new intake manifold gasket done last year,any suggestions?
Great video, I have the transmission removed out of my 5.3 Silverado, But it’s very clean in between the transmission and the engine, is this normal? Mine leaks and drips down the started just like your video shows it leaking
Can someone share a part number and link for the "Plate Gasket" as it was mentioned to be the number one culprit before the RMS gasket. I can find the gasket for the oil cooler connection point "block-off plate" (although i dont have it by my 4.8L).
I had taho 5.3 was a leak so dealer put dye in and could not dine the leak then I looked at it and realized it was the engine mount leaking 95 bucks for dye test and they were wrong
I believe he is saying that the rear main seal is leaking and or the plate. But I fell what your saying. What was the leak once he got the tyranny out?
I've been preaching this for years about the LS engines. It's almost always the rear engine cover gasket! There's also a porosity issue with the OEM rear covers where they will weep oil through the metal cover. People will change the oil pan gasket and the leak will continue. They'll then replace the rear main seal and the leak will continue. They'll finally replace the rear cover and gasket and the problem is solved. The camshaft position sensor is not in the back top like older LS engines but that's also a common leak point due to the o-ring going bad over time.
what to you consider an "older LS engine" ?
I’ve been doing the professionally for quite a few years. So far I’ve never seen a rear main seal fail on these engines. It was always the rubber portion of the two piece gasket flattened. The cure is to get the whole rear cover! I had only one come back and it was wicking oil around one or two cover bolts. Added silicone th these bolts. Was cured! 2:25 2:25 2:25 😅😊 2:25 😅😅😊😅😊😊😅😅 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 😊😅 2:25 2:25 😅😅 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 2:25 😊
@@DannyDisharoonWhen you say "rear cover" are you referring to the crankcase cover? I'm facing a similar problem on my vehicle and I'm struggling to find the plate he's talking about on a parts list
At autozone one rear main seal item comes with it @nickyaboi620
@@crabapple6775the gen 3 engines has the camshaft sensor in the back and gen 4 camshaft sensor is in the front. Gen 4 2007 or newer.
In my days, I never wanted to hear rear main seal. Always looked up and often it was valve cover gaskets. Enjoyed the class.
EXCELLENT camera work and narration. I’m dealing with this same issue. Thanks!
I watch all your vids here in England , ive been sleeping on the streets an in car parks but i just got a flat (i bed appartment ). To anyone in a similar situation, keep the hope bro or sis keep strong in your mindset, if you like god what the hell it cant hurt anything . Just keep yourself as personally clean as possible an your mind strong .if you need a chat I’m here for you all I’m NO guru but ive don it in England . Sorry for stealing your thread 😮😮
We've had about 35 of the 6.0 engines in our fleet I've replaced the rear main and plate gasket in only 2 of them and they both had 300,000 plus on them. Very durable engines.
I have one of them and the mechanic replaced the main seal 2 times then discovered the plate was leaking at the bolt holes in 3 places
I had a 1998 express van and the timing chain cover just split open.
We bought it brand new . All decked out VCR, TV, headphone jacks fort.
Regency .
Anyway to change the cover I had to change oil pan gasket and timing gasket.
Bottom of timing cover a rubber gasket was both covers gasket.
You wouldn't think that the gasket on a blank plate to cover the attachement for the oil cooler on engines that don't have the auxiliary oil cooler would be that hard a thing to get right, but they leak like mad. I generally pull the driver's side front wheel and reach in with an extension to remove the bolts with the least grief.
I have the 5.7 litre Chevrolet LS1 V8 engine fitted into a VY Commodore sedan here in Australia & I replaced the old olive coloured rear main oil seal which was 13 millimetres thick with a 10 millimetre thick black Felpro rear main oil seal back in 2016 & I also replaced the seal carrier gasket as well because it's a lot easier to fit the rear main oil seal when the carrier is out of car since it's harder to replace it while you're lying underneath the car at home.
The old seal carriers is deeper so I was very careful regarding how far to push it into the seal carrier.
I have replaced the oil pan gasket because I was driving over rough road in a Commodore meaning that the oil pan bolts kind of vibrated loose !
Great video. Can you do part 2 of how you fixed the leak
Crankcase ventilation build up can cause havoc on leaks. Not saying it's a issue here but it sure is the first thing i go to with leaks. Replace the PCV valve most people overlook and forget about then check for leaks see what happens. A bad PVC valve will indeed reveal the weakest link on engine seals and gaskets... I've seen it happen many times.
If the PCV hose is disconnected from the intake would that cause an oil leak? The guy who built my truck disconnected it from
The intake and said it’ll run better but it’s been leaking little drops of oil from the top driver side engine and down to the oil filter and to the tranny
@jonathandeleon5588 in no way would disconnecting the PVC hose be better. For one it causes crank case pressures to rise too high. Second, if the hose off the intake isn't plugged with something, that's a bad vacuum leak for the engine reducing power, idling bad, and consume too much fuel.
@@garyr7027 yea he plugged the intake PCV hose with like a little plug but the hose by the valve cover gasket is just hanging he told me it runs better since I have the truck cammed but I been having oil leaks like little drops idk if that could be a cause or not
@@jonathandeleon5588 tell him to put that pcv valve back like it was. Cammed or not that doesn't matter, a engine still needs crank case pressure relief or it builds up pressure from heat and blow by from the piston rings. Cams has nothing to do with piston ring blow by, which is normal even for a new engine. PCV valves aren't there just for looks, there's a good reason for them being there.
Flying sparks garage has a good video explaining that plate and rear main seal. If anyone is curious to what it looks like. I believe it's the video where they're putting the transmission back in to a Corvette. Good info as always Kenny nice wrenching.
Thanks for watching!
Oil leaks are a pain, especially if the transmission has to come out. $$$ It can be deceiving sometimes, that what appears to be a huge leak really isn't. A few drops of oil or trans fluid looks like a lake on concrete. That one is pretty significant though, since you cleaned it and all, you can tell it's pretty bad. At least if you pull the trans, you will be able to change the seals on the engine and trans, and that gasket you were talking about.
Not bad to do on a RWD. It's the FWD that are a pain in the ass.
Good morning Mr Kenny hope y'all have a wonderful day, thank you for this video, I always learn something from watching these.
Early models sometimes had a porous rear main seal plate that leaked thru the metal and you had to replace the whole plate.
My issue started when I changed the oil on my 4.3 v6 2000 chevy pickup. After changing the oil I had big oil spots on my driveway . I suspected the crush gasket on my drain plug, so 20 miles later I drained my oil to replace the crush gasket on the drain plug, GOT IT.. Well I continued to have big and bigger oil spots. Shoot either wrong oil filter or double gaskets on the oil filter. 22 miles later I got a new oil filter and I changed it, NO double filter gaskets.. I thought maybe the oil filter was defective. Either way it should stop leaking. NO , still having bigger oil spots. Basically it was the oil pressure sending unit leaking. I replaced it and NO more oil leaks. Regardless why did it start leaking after I changed the oil ? Because that’s the way Murphys law works. I thought that was going to be the problem on Kenny’s video.
Omg. That is insane. Glad you found it.
When I was a young teen just starting to mess with cars, changing oil, tires, simple things, I changed the oil on my dad's Ford and then the light was on all the time. It blew my mind.
In those days most cars just had idiot light for oil pressure which usually didn't come on until the pressure was almost zero, Fords would come on under about 10 pounds
The pressure was low but enough to feed the engine, not enough to turn out the light. The way it decided to start acting like that right after I changed the oil was not what this young kid needed.
The same reason a fuel pump tends to fail right after you fill the tank. 🤣
i've done these a few times. i pulled the engine replaced the rear plate comes with seal when it was easy to repair the exhaust leak at the left rear manifold and the list of all the other leaks . crank sensor oil filter housing oil cooler hoses ps hoses
On my 2000 Saturn 3.0 I have the similar issue. Of course 3 shops gave me all different diagnosis, and ALL were wrong. Valve covers, oil filter housing and oil cooler line gasket. It leaks in that same area between the engine and trans. I had the engine installed 2 years ago, and after about 6 months started the leak. It used to leak on the cardboard on my garage floor, but has since stopped in the past 6 months, but still leaks while running, because it still is wet and runs back along the trans and blows back on the exhaust pipe bend and smokes when the lights are on, and I can smell oil burning. I thought it was the main seal, but not sure what covers there are on a 3.0 around there. I put some 205 RE sealant in it and see what it does. The pan usually drains in about 3000 miles and I have to add a quart and a half between changes with synthetic oil. We'll see if that stops it. I'd hate to spend $800 to pull the trans to replace a main seal. I'm too old to mess with that kinda stuff myself anymore. Lol.
Edit: It started leaking around 138,000 and now has 162K in the 2 years the different engine was dropped in it.
Thanks, a customer of mine let his son replace rear main on his Silverado now I have to figure out why transmission doesn't work. I had been looking for that leak prior to his son making more work for me on trans now.
Excellent camera work. Very helpful.
I've seen many of these with a leak at the oil sending unit, they did put it in a wonderful place
That was common. I have done quite a few. Thanks for watching
Tip: LS motors leak oil easily if the pvc system isn’t correctly working and set up right. LS motors leak oil from flywheel bolt holes on the crank flange when the bolts haven’t been sealed. Both of these conditions are usually found on hot rodded motors.
Thanks for the info. I will keep that in mind especially since I'm pretty sure I'm putting a LS in the Camaro. Keep Wrenching!
Hey Kenny what would you recommend for a new used suv most reliable
Yukon of Tahoe
I rebuild transmissions and when ever I have the transmission off one of these engines, I always put my finger tip into the well where the cam sensor is located and have found many to be leaking, also there is a pipe plug where that block off plate is on the oil pan and it will leak and it cant be removed as installed, but when the transmission is out it can be checked for tightness or resealed.
Does that plug sit right behind the starter? I got a 4.8 that looks like it's leaking out of a bolt (where crank sensor would be on other models) right above oil pan gasket and just behind starter
@@Father_Adrian No, the plug I'm speaking of is on the other side "drivers side" it is there to plug a drilled passage for the oil cooler circuit in the oil pan. Leaking oil travels by two means, gravity and wind, so always remember that where its dripping from is not necessarily the source of the leak. Put sealer on the threads or check the O ring on the sensor or plug if it doesn't have a sensor where it could have one. Good luck, and be the oil leaking. Where would you go?
Thank you Kenny!
@Wrenching With Kenny This helps me a lot. I have a 2008 Escalade EXT, basically the same truck as this, But mine is the 6.2 with 4WD. I have had a minor oil leak for a few years, about 4-5 drops on the driveway over night in addition to whatever it leaks out while driving. The truck has about 110K miles which is low for a 2008. But after I did an oil change last week the leak got about 10 times worse. Constant drip while running and once parked it will leave a 6" diameter puddle on a smooth surface like concrete. I'm at the point of putting my oil change catch pan under the truck instead of a sheet of cardboard. I assumed it was the RMS so I put in some blue Devil RMS additive. The leak has slowed, now down to under a quart a day on a very light 30 mile a day commute and seems to get better every day. But last night I cleaned everything then started the truck and got under with lights and I see now the oil is running down both sides of the back of the oil pan and collecting around the trans inspection port. Inside the trans inspection port it looked just like in this video, a little wet but not nearly enough to explain the amount of oil I'm losing. I'm thinking oil pan or oil pressure sensor as it's coming down both sides of the back of the engine. I still need to look at the back of the engine above the oil pan. Thoughts?
07 Escalade with an oil leak here. Similar situation as yours. Oil coming down both sides of the top of the trans is what it seemed like. Changed my valley cover gasket, valve cover gaskets, oil pressure sensor and intake manifold gaskets while I was in there.
I’m willing to bet that the leak remaining is either this plate in the video or RMS. Gonna try to solve it this week
I fixed a bad oil leak on a 07 Denali, that was very difficult to pinpoint because it would drip down above the transmission bell housing, it ended up being the valley pan gasket.
Another well done video Kenny. I hope you have a great day!
When I had wetness near the rear main on my Chev 5.3 a couple of years ago, I assumed a rear main and decided to ignore it. It was a stupid mistake. Later when the oil pressure sensor finally failed I discovered that the oil was coming from the sensor up top. Doh!
I just had one a month ago. It's pretty amazing how easily it's mistaken for a rear main seal
Really? Do you know for what year and what the sensor is called? Also where about is it located? I'm scratching my head on a oil leak as well..99 Silverado 5.3.
@@j.v.1166 2000 Suburban, up top at back, oil pressure sensor, I did a video titled "understanding oil pressure".
Great explanation of oil leaks on these engines..
Thanks Kenney..!
Mr.Good Wrench , Leaks out (the Main Concern) and no second guessing! Too many part's replacers out there! Your videos are a learning tool with visual!
THANK YOU KENNY FOR THE FREE GAIN WE APPRECIATE YOU
Hope you get that job I have a 09 and would like to see the job done. Thanks Kenny.
Thanks for the video Kenny. I'll probably never use the information 'cause I'm a Ford guy right now, but you never know. Keep the good stuff coming.
Actually the method goes with diagnosis of any make/model. The main thing is to keep looking until you are absolutely positive on the diagnosis
My 2006 Tahoe 4.8 is leaking by the starter like in your video. Also at the end of video that gasket you pointed to above oil filter mine is wet all around there with oil also. I'm going to clean it like you did and watch it idle to determine where it is leaking. Thanks for the video showing this.
Easy fix on that oil cooler gasket.. the other is another thing
I think your diagnosis of the seal plate is correct on this one. However, I've seen those CKP sensors leak a few times. The o-ring is an odd size so you have to get a new CKP to fix it.
I've seen sensors leak before on other vehicles, but I've never seen one of these . Just personal experience... I'm sure now I'll finally get one lol
There is a guy on ebay that sells the odd size o ring to fix the leak
@eddiemiles1920 what's his name on there? Or part number? Thank u
In the older Gen3 LS V8 engines a leaking camshaft position sensor O ring can also cause the oil leak as well !
When changing the cam pos sensor on the older gen III engines (L59) how complicated is the relearn procedure? I hace adecent scanntool if that helps
It isn't difficult at all. Follow the instructions on your scanner. It should be under miscellaneous functions. Keep wrenching 🔧
Awesome video! I thought my 2011 suburban Ltz was just consuming a lot of oil…looks like I gotta take it in and have the rear main, the plate you were speaking of and the oil pan gasket replaced….not to mention my oil cooler lines…
If you are there at the rear main seal, change the plate and seal. Always
I have a 2006 Silverado 5.3
Had rear main seal replaced about a year and a half ago along with oil pan gasket and valve covers.
Still had the leak.
Had to have some work done a few months ago. Asked them to check the leak. They said it was valve cover gaskets and they were replaced again along with something else underneath ( don't remember what).
Stoll have a leak but not as bad.
As long as you have the money, I guess theyll have the time.
@@edsyphan3425 - This was 2 different places.
I think both places actually got some of it bit there us something they missed and may be this plate the video is about.
Hi that video helped me to find the leak on vehicle that I’m working on 👍🙏🏼
Would a borescope make some of these awkward inspections a lot easier? Plus it could be recorded as documentation for the customer.
I love looking at your videos I have learned a lot & fixed a few cars from watching you keep the videos coming I’m always watching 👍🏾👍🏾
This is a great video! Direct and to the point. Thanks
The oil cooler line connector block to engine block gasket, as well as the set screw plug in one end of the oil cooler line block is always suspect.
I replaced rear main front main and timing cover,, then a few days ago I done the sump just to find out it was the crank position sensor that’s about the starter motor 🤦🏻
Thank you so much that's where my Hummer H2 is leaking
Have this problem with my03 Tahoe. Not looking forward to pulling tranny. I’ll replace rear seal oil sensor and cover plate while it’s accessible. Some fun!
Thanks so much for this. My truck has the same leak
Great video. I suspect that's what happened to my 2008. Also, what is the technical name for the oil cooler gasket though pointed out at the end. I might as well replace that while doing the job.
You sure are a great diagnostic man.
I have a 2005 Yukon 5.3L 4x4. Looks exactly the same. I may have a very slow rear main leak. I just got it and am watching it now after a fresh oil change. Has 216,000 miles on it. Seems to run great though.
3 questions:
1. Was there a cover on your inspection hole that shows the bottom of the flex plate? Mine does not have a cover of any type. I can see the bottom of the flex plate.
2. I have a pair of ramps that raises vehicles back or front tires by about 12". Would that be helpful to use for this job?
3. So the rear seal has two parts? A shaft seal, plus a shaft seal cover gasket? Does the cover seal just keep dust out? It doesn't have a gasket across the bottom of it, does it?
Correct. There is a radial oil seal and a rubber seal for the cover plate. The bottom of the cover plate is what the oil pan seals against with it's own rubber seal. It's important to align the plate properly so that the seal bore is concentric to the crankshaft and the bottom of the cover is perfectly horizontal. The alignment tools are cheap and can be found on Amazon or eBay. You install the cover with the alignment tool inserted where the seal would be, and then tighten it down and install the seal last. There's also an alignment plate for keeping the bottom horizontal in case the oil pan isn't installed, which is the only way I've personally done it. Better replace the oil pressure sending unit while you're under there, as well as any sensor o-rings. To be honest, it may be best to have the oil pan off, and to change the pick-up tube o-ring, but that's quite a bit more involved, especially with a 4x4. Just my 2 cents.
@ryanmcrae3593 When the cover gasket is not done right, where is the oil coming from that leaks from the bottom of it?
If the oil pan seal is good, crank rear seal is good, but the cover plate is not sealed good, where does the oil leak out of?
@@thesetruths1404 I honestly don't have enough experience with the LS engines to be able to tell you for sure. Maybe someone with more knowledge of these issues will chime in. I'd say the oil would most likely be coming from where the cover mates to the oil pan.
great attention to detail. thank you
Nice to know the moved the knock sensor.
Also the oil cooler gasket near the filter leaks and is known for problems
I thought that I had a leaking oil pan gasket on my truck but it turned out to be a leaking gasket on the driver’s side valve cover. I ignored the leak for about 10 years until it got so bad that it was starting to leak on the exhaust manifold. Luckily, the gasket wasn’t that hard to change.
Dang! 10 years!! I changed mine tonight in about 20 minutes because the PCV was clogged
Thx for the advice, just bout an 07 Sierra leaking badly
Thank you for this.
I'm so torn on what to do with next with my 08 5.3 Chevy 1500.
She leaks about 2qts oil every 5k miles, and has done this for about 25k miles. I replaced the oil pan gasket, and it still leaks. It was stupid of me because it will only leak after it's been driven, so no duh it wasn't the oil pan gasket.
After watching your video, I don't know whether to replace the rear main seal, oil cooler, or the rear cover and gasket. DANGIT.
How many mechanics would go to this extent to diagnose an oil leak? Most would probably say you need a new engine!
I'm very curious about the oil cooler gasket that you said.my truck does not have one but it does have those two bolts and gasket. I've changed the oil pan and gasket and still leaks .took it to get an alignment and the technician said it was a engine seal but didn't show me...99 Silverado 1500 5.3 2WD.
What's the plate called ?
ya some shop changed this on a 06 5.3 and its leaking worse now 40k miles later than it did when it had like 140k. Sucks removing a transmission on jack stands
I've seen a lot of oil pressure sending units on LSs leak oil.
Glad to know that is there I have to replace the transmission on my '01 Suburban so I'll go ahead and replace that seeing I have around 250k on the odometer
Whoa, that is a bunch of miles on one of those, you may want to do like Kenny does and just find a replacement out of a wrecked vehicle that has 70k miles or less, engine and transmission. Just a thought.
@@jthonn the engine is still running strong jost slight oil leaks trans lost most of 2nd gear so it's getting a 4L80E
@@jeremyself2156 Good luck to you, change anything you can that's normally hard to do while you have it apart. Rear seals, gaskets, oil sending unit and O2 sensors, well you get the picture, I hope it all goes well.
It's the same set up on a 3800 v-6 I had to replace the cover too
Could the leak be caused by incorrect cleaning/sealing of the rear corners of the oil pan gasket, when it was replaced?
(Where the oil pan gasket crosses the end of the rear cover plate and its gasket).
J
I have learned something, thank you! 🙏🏽
Good Morning Kenny..! I’m not so sure about an Avalanche … or a truck named after an avalanche..and I am a Chevy Man .. can’t wait to see how you fix it ..good luck 🍀
My 4.8 is doing the same thing. Curious how much a reputable mechanic would charge to fix this. I usually tackle everything myself but pulling the transmission isn't fun.
For the longest time I thought I had a rear main leak. Then I did head gaskets and found that all the oil I thought was coming from the rear main, was actually coming down from the back of the valve covers.
Was it leaking a big puddle and leaking after you shut the truck off and got a nice puddle lol
I have leak btwn the engine and trans on a 6.0 that occurs as it sits on a lift through winter storage. Is there oil trapped behind this plate that would drain out after the car has been sitting for an extended period of not running. All the oil should be in the sump by this point and not above the crank seal
Another way to find the oil leak is put that fluorescent dye stuff in the oil and use a scanner/viewer to see exactly where the oil leak is coming from.
Yes done that to confirm valve cover is leaking slightly.
Work at valvoline ane see this every day
Good video! I was just notified by my dealership that I have a rear seal and plate leak. I will trouble shoot this myself but, what angers me so is with this dealership, every time I take mine or my wife’s vehicle in it’s something else. I don’t wanna say it’s sabotage but, every time they point out an issue I’ve gone in and repaired it myself. At seventy five, my days doing this are becoming harder. If they’re doing this to me, I can’t imagine what they’re pulling on the neophyte that has no sense of engines or cars. I take really good care of my vehicles but, I’ve had it with this outfit.
@WrenchingWithKenny Well, did you replace it ? And was that the issue ?
I was wondering the same. When the tranny was out what was the leak? Appreciate it
I have a 2002 Blazer with less than 70k on the 4.3 and it leaks inconsistent,start up more and move out of shop park leaks about an 8 inch circle of oil on concrete. Drive for hours park on concrete, maybe 2-3 small drips ???? Not filter,rear main had new intake manifold gasket done last year,any suggestions?
Great video, I have the transmission removed out of my 5.3 Silverado,
But it’s very clean in between the transmission and the engine, is this normal? Mine leaks and drips down the started just like your video shows it leaking
In other words , do them both since you have to drop the transmission anyway?
That is 100 percent rear main seal housing leak.
What about the barbell ??? Was it ever resolved???
Can someone share a part number and link for the "Plate Gasket" as it was mentioned to be the number one culprit before the RMS gasket. I can find the gasket for the oil cooler connection point "block-off plate" (although i dont have it by my 4.8L).
Automotive Technician - the art and science of doing the almost impossible - for a reasonable fee.
Is this the part number for that seal/plate? GM Genuine Parts 12639250 LS Rear Block Cover
No, Gromit! Those are the wrong trousers!
Do these aftermarket plates and seals work just fine? Theyre like $40 for everything. Or do you have to buy OEM expensive stuff?
So what is this plate called?? So I can order
Had a leak on my 2000 gmc 5.3. It was the oil cooler block off plate
I had taho 5.3 was a leak so dealer put dye in and could not dine the leak then I looked at it and realized it was the engine mount leaking 95 bucks for dye test and they were wrong
What’s the name of that plate and gasket, so I can look for it at the part store.
very helpful thanks man.
@southside_prepper I'm glad I could help. Thanks for watching. Keep wrenching! Kenny
What’s the part number or real name for the part he’s mentioning
I had a 3800 motor that leaked also on that rear main plate
you're telling us it has something to do with removing the transmission?
I'm not sure what you mean. You have to remove the transmission to replace the rear main seal. Keep wrenching 🔧
how many hours is this job?
About 6 hours. It's a big job since the transmission has to come out to do the repair. Thanks for watching, and keep wrenching 🔧
@@WrenchingWithKenny my guy is changing me $1400 to replace cover seal and rear main seal. It that about correct
Sorry you have that going on. The price sounds about right. Some vehicles it would be more than that.
Frames on these trucks could use a little oil leak
So what’s the problem?
could use your borescope
Thx. Good explanation.
Damn , that truck is clean underneath for a 2007
And another aftermarket cold air intake!!
You never really say exactly whats leaking? You make an earlier comment about a crank sensor but you don't say if that is the issue.
I believe he is saying that the rear main seal is leaking and or the plate. But I fell what your saying. What was the leak once he got the tyranny out?
Where is the fallow up video on this one? 🙁