COOKED C4 Corvette LT1 TOP END TEARDOWN! Gnarly Damage! How Does This Even Happen?
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- Опубликовано: 29 сен 2024
- Welcome to another installment on 95 Corvette! I bought this car from the auction with minor front end damage. If you haven't seen the other videos, they can be found here: • Rebuilding a wrecked 9...
I first assumed it was just the accident damage but a little investigation in the first video discovered much more work needed, it had low compression and pushed coolant out! So, as always, a quick fix project becomes a big one. Story of my life!
In this video I tear the top of the engine off to inspect the heads and gaskets as I assumed they were blown. WELL! I was in for a surprise! I did not expect to find what I did, and its the first time I've ever seen anything like it!
I hope you enjoyed the update! As always I love all of the comments, feedback and even the criticism. Catch you on the next one!
-Eric
![[Limbus Company - Teaser] Season5 - Oblivion](http://i.ytimg.com/vi/8anKuEeZLeI/mqdefault.jpg)
For someone that supposed to know cars knows the corvettes whole drive train to back wheels to front wheels needs to drop as one unit including exhaust removing 8-12 body bolts
They are a tunnel transmission
This makes corvette so interchangeable
How did you not know that
Are you suggesting I pull the body off of the chassis to pull the heads which took me 3 hours on camera?
This is why mechanics don’t agree with engineers. There is the “get it done” way. And then there is the stupid book that the engineers wrote. Guess which way is the best. Answer whatever way the guy holding the wrench decides.
@@wrecksandtech I think that engineers don't put as much value on stuff like ease of repair and servicing compared to having a more efficient/better system, which leads to certain stuff just being harder to work on.
Judging by your ridiculous comment, you never held a wrench in your hand…
Who pulls the entire body to remove heads? Well, I guess you do/would... Smh
You got the dipstick out without no damage .
2 torched heads was the price of that miracle .
The GM Gods work in mysterious ways .
My brother and I would watch your videos and message each other when a new one comes out so the other could watch it. He passed away unexpectedly last week and I miss him a lot. Now I get sad when a new video comes out but it is bitter sweet because it reminds me of him. Thank you for helping me remember him! I enjoy all your videos.
😥
I’m really sorry to read this. 😥
So sorry for your loss.
Condolences my fellow human.
My Family will Pray for You and Your Family.
Sorry for Your loss, we wish You our most sincere condolences.
What makes your videos fun is that you are doing the work.
I've seen a ton of C4 videos and the person only explains the process. You're doing the work and talking us thru the process. It looks complex till an expert. Shows us it can be done.
I'm grateful for your channel and knowledge. (:
I'm really fascinated by this head damage. It looks like highly concentrated heat, like a plasma cutter focused right at those two spots. The rocker chambers look pretty clean though, not like heads from an engine subjected to long term high temperature abuse. This damage probably occurred over a short period of extreme use, some relatively abnormal event for this vehicle, a high speed police chase would be believable.
If I recall, the '95 Corvette used an early OBDII, or OBD1 Enhanced, engine control strategy. It came out during the transition so it's not impossible to think the program may have been less than optimized. Under extreme operating conditions it may have been running some way out of bounds timing and AFR parameters. It would be interesting to know what secrets the ECM holds.
The damage is low in the head's installed position, so if the engine were low on coolant, the high side of the combustion chamber, on the opposite side, would be the first subjected to untransferred heat. The effect would be mooted however if the coolant left the system all at once, like if the bottom of the radiator were ripped out and the engine continued to be run at high speed. Curiously, the damage is toward the center of the block, not furthest away from the water pump and radiator outlet, like the #7 and 8 cylinders would be. Here again, if the system had no coolant at all the center of the engine is where heat would concentrate. Also, the center of these heads is where two exhaust chambers come together, again, more concentrated heat. That all seems consistent with identical damage occurring on both heads, in the same location, at the same cylinder positions, 5 and 6. Combustion chambers #3 and 4 probably weren't far behind for the same damage.
Aluminum liquifies from its solid state pretty fast, just a few degrees is all takes to go from soft to molten. It also conducts heat very rapidly, and in response to heat, it expands a lot. All of this would come into play during a brief period of extreme high temperature operation. Also, abnormally high temperatures would have excessively expanded the heads exerting high tensile pressures on the bolts and spot faced bolt perches. Once cooled and contracted that would have left less yield pressure allowing the bolts to break free more easily during disassembly then if they had been at their specified torque/pressure. We saw evidence of that.
The failure does not seem to be at the thinnest part of the casting, but does seem to be along the most direct route from the combustion chamber to the exterior of the engine. The escaping heat did not deflect and dissipate into the water jacket, it continued on through the next layer of casting ejecting out the exterior of the head. That means the hot gas jet first blew out the bottom of the combustion chamber into the steam port, then focused on the exterior wall until it blew that out, and finally had an escape path to the outside. Wow, crazy sequence of events! Would love to have had an inside view of that happening...
In all it seems like specific mechanical design features, extreme engine operation, a highly compromised cooling system, and possibly unoptimized engine control, all conspired to produce this really weird material failure. For sure I've never seen anything like it, but way cool to see and consider. Thanks Eric, this one's a real hoot.
I am guessing that the head bolts stretched it were not torqued properly. I had a car that kept leaking coolant no matter what I did, chased it for almost 80k miles, when suddenly a bad "exhaust leak" started. I pulled the valve cover off, and there was a busted head bolt, no valve cover gasket (tons of rtv instead) and no exhaust manifold gasket at all. The manifold was sealing from carbon build up, pretty obvious it had been run that way for quite a while before I got it.
Pulled the head off, and it was leaking coolant between cylinders, right where the head bolt was broken. It passed a cold compression test, and on short drives, no problems at all, but it would eat coolant and need topped off every 10k miles or so. My guess is as it heated up, the head gasket would start leaking, probably only under load.
You can see in the video some of the head bolts are really tight, others look almost hand tight.
I don't know why someone would be messing with head bolts on a 45k mile motor, but this screams tinkeritus to me. I think someone pulled the valve covers, started retorquing the heads and forgot two.
Excellent deductions! I tend to agree with your theory. 🤔
Weekly project updates! Wonderful news! Thank you!
My 94 Trans Am I bought new has 337.000 miles on it now. LT1 engine, never been touched, even the timing chain is original. Still runs like new.
Original Optispark as well, right?
@@michaelkrenzer3296 my 95 corvette z07 has just over 40k and it is completely original. I have never had problems with the Optispark, but my water pump started to fail and leaked water onto the Optispark. Fortunately, I caught that within the day of it starting to fail, and replaced the water pump before running the engine again. I know that a lot of Optisparks have been killed by failed water pumps, as the weep hole is just above the Optispark, and the coolant gets past the Optispark seal and destroys the internals. That’s one of several things you have to be vigilant about the lt1 engine.
@@jvaubry Mine was more a tongue cheek comment about the high mileage engine I responded to with no issues. The LT1 has a special sound to it that will always make it...special. both crossfire and optispark got a reputation that is only partially deserved. For GM, both systems were cutting edge with some less than perfect design touches but the systems themselves were not inherently bad. The Doug Nash transmission I have a harder time with.
I have an 87 with the 4+3 and can concur that the ratios make no sense and the shift feel is like a John Deere tractor.
@@michaelkrenzer3296 No, its on its 3rd.
Man, in the 21 years between when my '73 was built and this '94 they sure managed to cram a whole lot more stuff into the engine bay!
Nothing is easy to work on, on a corvette,
I’m doing all 8 body mounts, without removing the body, on my wife’s c3 this weekend.
Even the rear end pinion seal replacement, was no fun!!!
Great video, I feel your pain, and also your passion! It’s why we do cars!!!
Great video as always!!
You took something apart mid-week, Your the man.
I haven't a clue what the original problem is, but it must have been running like shit.
And didn't happen at idle.
Thank you, thank you, thank you! Every once in awhile I get the urge to buy a Corvette. I think YOU have cured me of that urge. The lack of service room, the extensive electrical connections and superfluous plumbing and detritus attached to that car has permanently dissuaded me from ever being Corvette curious again.
That sturdy iron LT1 short block is a big reason for why i like the LT1 so much!! If that was an aluminum LS that whole engine would have been garbage!!
I'm supposed to be doing homework, emails, and looking for work post-graduation. Video gets posted, all that stuff can happen later 😎
I'm so glad I flipped the 92 Vette I bought to part out after watching this video . Extremely awesome video as you have more patience than I would have had . After just a very few minutes of looking at what it would have taken for me to do what you did I saw that " I ain't even gonna try to part this car out " . Great video sir
I don't know this guy's name, but I have watched a bunch of his videos and he seems like a really good guy. As a former C4 owner, I approve of this video.
Eric
Most people call him Eric but I call him Dr. E engine examiner.
Adam Sandler
Eric but not to be confused with Eric O. From South Main Auto
If you got that car after it was totaled by the insurance company they probably blue them holes in the heads the outer hole is to round like a torch tip having been a mechanic for over 40 years I have seen this done several times
Yep, at 28:24 you can see the burn pattern coming from the outside to the inside of the head.
Not doubting your theory, it actually makes a lot of sense. But any idea why they would purposely wreck the heads?
I believe you are 100% correct , just like @ the clubhouse said , the burn pattern is totally wrong.Thank you Thomas for your astute observation.
@@jaredbawden6707 they do that so that you can't resell them
@Thomas McNulty I assume this is because it was in an accident? Doesn't make a lot of sense to me if the car was sold as a repairable write-off
I love the spaceship look that all 80's sports cars have
Wow, that's crazy! I've never seen that before.
You have more patience than I do, the engine would have been out of the car! Thanks for showing what happens when the oil changes are done like the manufacturer recommends! I have always done mine max 2500 miles or when it gets dark. This goes for my cub cadets also. New oil and filters a lot cheaper than new engines. Sure enjoy watching what I did for over 35 years and glad to work on my Ford 239 flathead V8 8BA great to do after retirement. Again, keep up the amazing videos.
This is a first. I never seen that happen to cylinder heads before. Yeah definitely check the fueling issue to prevent from going lean again. I really like this channel and updates on your projects.
I always learn something from these, Thanks!
That must have been the infamous Cross-Fire injection in action ;)
Pinhole leak in intake manifold gasket? Those two cylinders were on the same plenum, I think. This happened to me on a Chrysler 3.3 V-6.
It’s always amaze what people will do to their cars and not even realize it.
I think at 49K I would still put a new set of mains and big end bearings in it. Probably a set of rings as well.
Yea always have a hard time with dip sticks. You ought to invent a dip stick puller where it pulls out with very little trouble and to where you can re use it.
I think a different camera from usual was used.
Great video!
New heads, nice. Be good to see it run. 👍
I have seen a torched gasket, but the head lived on. This is your big chance to do an upgrade.
OMG love this guy, no homo, being able to watch these catastrophic wreck tear downs without having to get dirty, amazing. Gr8 entertainment bro. Much better than like totally boring Might CAR Mod, which is really stale.
Peak combustion temp is at stoichiometric fuel mix (14.7). Going leaner or richer from there lowers the temperatures. The odd thing is the gasket blew between the two closest bolts and right where there is a cooling slot.
I would say perfect candidate for some performance heads and a bit of upgrading aswell
Love the channel. Maybe you could do a segment on best(or worst) dip stick removal.
A parts tray would stop me worrying about those bolts sitting there;)
I have one of those Rubbermaid plastic carts. Two levels, no sharp edges and easy to clean with a pressure washer. Never stoop to pick up tools or parts again.
I felt the same way. If that had been me, every one on them would have been knocked off.
The exhaust valve in the head chamber that torched through the head is different than all the others (28:21 min). I think that someone had this engine apart before and screwed something up.
Good catch! I hope Eric comments on this.
The 90s LT series motors were the bridge between the dreaded L98 and the legendary LS1. Without LT1/LT4's flaws, GM could not have set the benchmark that defined the LS series motors.
That engine was overheated and driven until it shut itself off. I'm not surprised that the bottom looks that good. Those heads were a failure point in those engines in Corvette's early LT-1 years
That thing definitely overheated. It wouldn’t have been able to burn through a coolant passage if it was full of coolant. I would definitely put new piston rings in, they probably lost their tension from the heat.
Really like your videos especially the ones you do on vehicle restoration.
Always the same with every car: "Oops, room for a wrench - let's place a bracket there ASAP!"
Wow.Your right lean condition.
I wonder what the inside of the iron headed LT1 in my 96 Buick Roadmaster sedan looks like with over 173k miles.
Probably like new!
Nice work
I wouldn't scrap those heads. Aluminum is easy to weld. A little grinding and resurfacing, you wouldn't even know there was damage. It might be worth it to the right buyer.
Looks like someone torched the heads
I would say ECM issue concidering only apposing cylinders where involved. Bad gas would have effected all cylinders.
They drove it like they stole it.
Thanks.
I would think a check engine lights come on if running in lean condition . That must be a week point in casting of head. Being burnt and melted in same place
Great excuse to learn to TIG weld aluminum...😉
i have a set of heads for this if you need them
Interesting tear down. 👍
The under the car part of the ground me thinks🤣
After watching a vid from you, I make an oil change. Everytime. Just in case...
on that passenger head -- why are the valves all mismatched? some are dished, some are not. weird.
Do I finish Caress of Steel or watch this. I think ..... both
90s GM engineering at its finest
Interesting head damage!! Send them off to "Pakastani Trucker" channel, sure they could weld them up and would be just like new! Hahahaha. Jokes aside, they do do some impressive shit with so little tools and materials. And yeah, we all know the repairs only last so long.
Why would you assume it wasn’t overheated? 2 big holes leaking coolant = overheating in my book
On one of your early videosi think you said that the LT1 was abad motor.???
Time for a community poll inspired by todays project:
Worst vehicle to change plugs and wires on?
Heads and cam
What's the 15" wide tire go to that we see in the ending segment?
I’m thinking the owner ran regular gas…causing this to knock like an sob. This car MUST be run on premium. Pretty neat o
How clean those cylinders are…tribute to mobile 1. I need a used headlight motor with the three attachment bolts. Do you have one for sale.
I bet I do. Shoot me an email and I’ll see what I can do. Importapartsales@gmail.com
Get an old school LT motor they said, it’ll be fun they said… An in-line 6 BMW is easier work on!!
Can’t keep running newer cars when overheating. Yup older cast iron engines can take more abuse. Good ole days are gone 😢
Possible to weld this head, whwn its alu
If I had a dollar for every GM dipstick tube that gave me headaches….. I would have like 5 bucks. 5 very hard earned bucks.
What happened to the mystic cobra?
nice video, thanks
Running to lean interesting
If you were ever wondering why some things cost sooo much to repair…here’s your answer.
I can see where a Chevy flat rate mechanic would be unhappy with working on a Corvette. Everything is a very tight fit, and there's no access panels to help out.
After 55 years in the auto and truck fields I have never seen a burn like THAT!!!!
@mikebaldwin4229 ,Yeah! That was intense... But aluminum does melt at fairly low temperatures... It first becomes annealed and looses it's tempering at around 475*F. Then it becomes very soft, bends and distorts very easily.... Threads start pulling out of annealed aluminum castings... But these holes coming from the combustion chamber, were caused by detonation... An un-controlled burn of fuel that could be caused by numerous events that quickly develop... But one thing is certain with detonation: Excessive heat either inside of the combustion chamber, outside of the engine & it's cooling system or runaway temperature increases, is almost always a major factor of what caused it... In this case on both heads, close to the same areas of the deficiency that lack proper heat transfer abilities, for the materials being used to harness this much energy release.. Major damage, that probably could have been avoided, by using a more proven method to keep the detonation and the eventual thermal runaway conditions, under control...
@@michaelmartinez1345 but those holes weren't coming from the combustion chamber, they were from the water jacket in the head direct through the gasket to the block.
@@michaelmartinez1345 Seen the same But it was from non gm antifreeze static electricity from spark plug ground
the spark wanting to cross as close to spark plugs as it can
but milage is way higher like 100.000
optispark time
the Dex cool was engineered to disperse the Electrolises
and the aluminum is peeling in layers you can tell
Unusual space to burn a head through. Never seen that before. Pistons should have been torched first. Aluminum heads can be welded, but these aren't that hard to find and the aftermarket has better if you went that route.
This channel keeps getting more and more entertaining, man. Your content is fantastic. Keep it up. One of my favorite automotive channels these days!
I think that was a regular HG failure to start with, but someone kept driving it hard and what you are seeing is the erosion of the cylinder head by the combustion gasses.
Agree. I would expect piston damage if it was lean enough to torch the heads.
I wonder if somehow improper head bolt torque (on those cylinders) at factory may have played a part.
Um he did say it was in a collision, the cooling system was breached and it ran til it burnt up.
@@nbrowser "Um" he also thought it was caused by a fueling issue, which is very unlikely IMO.
Dude, I’m genuinely impressed with your ambition. To go from rebuilding a Porsche to a Corvette..... just Awesome.
As someone who has pulled heads from a C4 before, I felt your pain quite intimately when it came time for that exhaust to be removed. Excellent video!
with each upload this editing just gets better and better
Eric Sandler at his finest
I just wanted to say thank you. My wife and I've been watching you since you started this channel and we always enjoy it, you're funny you're clean and I get to learn a lot. Especially the vehicles and engines I don't want to buy. Go Ford!!!
I try to watch all of your videos. Not once have I read some one bad mouthing your business. If I need an engine I would not hesitate to buy from you. Carl
After tens of thousands of cars through our shop in almost 40 years, I've never seen something like that on both sides. I'd guess lean running, not bad gas. Maybe a vacuum leak.
That block's deck still might be worth checking with a straight edge on those hot spots. Even so, that's crazy!
hmmm.. corvette.. Arkansas... crashed.... sounds like corvette met trooper byrd aka the byrd man. prob a yt video of it.
It boggles my age-addled mind that you can remember where all the nuts and bolts go when you put these cars or engines back together somewhere down the road. Glad you got new heads for this engine, although I am somewhat disappointed that the dipstick gave up with such little fight.
My thought, as well. Usually, when I take something apart, the bolts are bagged and tagged. Or bagged and zip tied to the part they held in. It takes time, but it is SO worth it. At least for an amateur such as myself.
I thought the same. But if he gets stuck, he could check his video.
Eric's arch enemies are dipsticks. And with reason.
A mid week tear down! What will Eric give us next? I've never seen the kid of damage that this car had. Good luck.
I could be wrong, BUT I don't remember a teardown this last weekend.
@@briananderson8733 There was one Saturday,
Kid of Damage is my new punk band name.
Looks like maybe Nitrous
That's some wild blow out. I've seen some perplexing things under warranty, but nothing even close to that.
Watching you tearing down an engine and it's not even Saturday? What sorcery is this?
14:11 If I could move my hand that fast, I'd never leave the house.
Underrated comment! 🤣
Lmfao
Looks like a nitrous experiment gone wrong.
why just one pair of cylinders then? why not the pistons affected?
@@ghostrider-be9ek Really good question. No material transfer to the pistons. Pistons are mint for the claimed mileage. But what else torches a head like that? I have visions of someone cracking a nitrous bottle into an open intake at wot.....
Absolutely amazing that the block wasn't damaged.
It had sacrificial aluminium heads to look after it
A very good machine shop can save them aluminum heads. I have seen this a lot on boosted engines. Once you get it back together. Have the tune on the ecu checked (Or Prom) that is a really bad lean spot in the map.
Nice work, I have a c4 as well and it is tight for space under the hood, strange damage to the heads thought! Strip down the trashed heads and save some of those valve train parts.
I’d say it’s the easiest car I have ever worked on. Being able to sit on the tire and work is a dream compared to any other car where I am in a standing hunched position. I have a ‘92 6sp 🤙
@@DR.P3RKY you have a point about sitting on the tire! Mine is a 1989 Z51 coupe and they come with the ZF and 3.33 in the rear end.
@@DR.P3RKY Wait until you have to get under it. You do have a point about the fenders being out of the way, tho.
C4 probably has the most aggressive layout of any Corvette. It's like looking at an Indy car.
It also has one of the lowest seating positions of any Corvette while maintaining ground clearance, meaning, it's has a lot of room to be lowered, if someone wants to.
You should rename the channel "Tales of the Dipstick".
You know, I work on my own cars, a '14 Cayman S and an '01 Subaru Outback LL Bean, and for 19 years I drove and worked on an '85 Porsche 928S2 5 speed. I'm an amatuer driveway mechanic, but it sure seems to me that it would just be easier to drop this engine and work on it on a stand.
LOL - The sound of a socket or wrench clanging as is disappears into the harness/bracket void. Waiting to hear that 'hit the ground' sound is the longest 1.5 seconds of your life.
Im sure I've seen that car before
Or, at least, some parts from it 🤣
Also waiting for the dipstick battle to commence
Interesting failure, one cylinder burned through in each bank, and the piston tops look OK. Did you happen to do an ECU code dump?
Didn't need the "Safety Tote" even once!
I am surprised the pistons tops didn't take more damage, they look great!