Great video as usual Bob.. as I mentioned in other videos you have made.. my son and I are restoring, rebuilding, modifying his 86 xjs. Being a licensed mechanic for 42 years and worked on hundreds of jags... the small 10" electric use to die, mostly of bad connection or temp trigger sensor on the water pump housing.. I have installed a half dozen twin electric fans on these toys.. never hits 200 ever again..I removed both the old useless mechanical and small electric fans.. I made a custom shroud with venturi divider between my 2 - 14" vortex electric fans.. the car never passes 186F. Less than half mark on gauge.. also swapped temp sensors locations.. there incredibly quiet, insane amount of air circulation and runs for about a minute or 2.. now there are several companies that sell a complete kit for these cars.. but only use 2- 12" electric fans.. good luck my man.
Great video Bob. After 25 years of same problems and meticulously maintained engine I finally fitted large HO Spal fan. Big draw on alternator and not tested in traffic in v hot weather but much better now
I like that you show “hands on” doing the work to do the work. Being a backyard mechanic it’s helpful to see it being done and your honesty about how sometimes making some fixes might add issues in the future. You show it maybe a classic car but it can be worked on if you take your time and pay attention! Keep the good work going, thanks it’s very educational. 1990 XJS V12 still drivable and hopefully improving as time keep going!
I have this problem with my V12 - too cold when it’s cold and too hot when it’s hot. I’ll be watching with interest! I also have a replacement fan, and clutch, that I will soon put on, but I admit I never had much hope it would make a difference. Seemed wise to get rid of the infamous exploding yellow fan anyway.
Bob, turn the heater on full blast, LoL. I assume you did a coolant flush of the engine to wash out the passages as much as possible. Since the rad is in great condition, perhaps there is a chemical that you can run through the system, do a flush, then refill. Knock on wood my XJ6 runs cool, but next summer when she gets the V12....so I'll be following your series here with interest. When the car does get the V12, I plan on moving the clock up on top of the dash in a 3D printed enclosure and putting a second H20 temp gauge in the clock space (I have a Series 1 with the row of gauges). One for bank A and one for bank B. Looking forward to the next in this series. Cheers.
I actually had to use the heater trick on a couple of 90º+ days on a road trip to Seattle with my first XJS. I had a 24 count flat of gatorade on the passenger seat. Didn't take a pee all day. Brutal.
I think the slight assymetry you noted in the distribution (and shape) of the fan blades may be intended to avoid resonances created by rhythmically beating the air.
That was a thought I had but my son had a land rover discovery and said the clutch removal procedure included pulling the clutch through the gap. It makes sense.
When I got my XJS v12 it would overheat in minutes (mismatched and stuck thermostats) I replaced them both with 160 degree thermostats which works well for me since I don't ever plan to drive it in the cold.(chose such a cold temp because the idea of dropping a valve in an engine I can't afford to replace is scary...)
after three months off and on i went the homemade shroud and electric fan route....(2x mustang fans). so far...so good. both pull through radiator....which is aluminum. not cheap but worked well. took damned near 20 hours fab time. good thing i am retired and have the time to mess with such things. 🙂looking forward to seeing how this turns out for you to be sure.
Minneapolis…..I recently rescued an 1987 Lister Jaguar XJ-SC that was originally purchased at Downtown Jaguar in, Minneapolis MN already converted to a 5 speed manual for the V12. 1 family owned and only 23k. Working my way through the details to pass inspection.
An interesting vlog thanks Bob. You touched on the condition of the rad coolant side being a potential issue, it certainly was on my s3 E type as the car aged. A visual inspection of the core is difficult, did you have the flow rate/pressure drop of the rad checked by a specialist.
@@thecampchaoschronicles9567 hmmm. Maybe. Lol. The Combs mk2 and e types had them. (Dare I say for a reason). Lol There’s basically no space around the v12 as u know of perhaps the latent heat build up is a partial factor…. I’d say it’s probably a few one percenters tipping things over the edge….
Have you considered this. No matter the size of the mechanical fan you fit, unless the considerable heat created by the engine can be evacuated from under the bonnet, then there is effectively no heat transfer/exchange taking place. There's only damed, superheated air with no direct path to escape. The engine and all of it's components are effectively being cooked to death within the confines under the bonnet. Cooling air needs to pass through the radiator core, absorb the heat from the coolant and then pass out of the confines of the enclosed engine bay. Appropriately placed louvres toward the rear of the bonnet would facilitate the egress of super heated air. A simple test, would be to raise the rear of the bonnet (closest to the windscreen) and take the car for a drive on a hot day.
That's why the front air dam is so important to the operation of the cooling system. My '90 convertible came without one and it ran within the N range. Then I put one on and it never got to the N and it was hotter, later in the same day. It creates a low pressure area behind it that evacuates air from the engine compartment. It's got to be there.
No qualms about the air dam, but for it to function effectively the car needs to be moving forward at a reasonable speed. When stationary in traffic for lengthy periods, then it's a different story. There's still a need to evacuate the super heated air from the confines under the bonnet, especially at the rear of the engine. Another issue of concern, is that confined super heated air will also over time destroy any plastic fittings on the engine and also harden the insulation of underbonnet wiring which ultimately leads to cracking and flaking compromising critical electrical connections.
@@enigmasvids9615 No argument there. But Jaguar shipped these things all over the empire to some pretty hot climates. Having been active in a number of forums over the years, there are people who live in places liken the southwest united states that have absolutely no problem with traffic. My '90 convertible is one of those cars. I don't know if this was a problem for the first ten years of production or not. I believe it is more of a maintenance/repair issue than a design flaw with the car.
Jaguar may have shipped them all over the world, but they certainly didn't fair well with the summer heat often prevalent in OZ. Have you sat the car idling in traffic for any length of time during a hot summer? You can further aggravate the situation by operating the car's aircon whilst stationary. Not trying to rain on your parade just listing my experiences with English cars of the period in climates that aren't as agreeable as the general weather conditions of the UK. Although the current heatwave would be something of an exception.
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I did not realise, that incorrect ignition timing is also a reason for overheating in the engine. More of this content!
Great video as usual Bob.. as I mentioned in other videos you have made.. my son and I are restoring, rebuilding, modifying his 86 xjs. Being a licensed mechanic for 42 years and worked on hundreds of jags... the small 10" electric use to die, mostly of bad connection or temp trigger sensor on the water pump housing.. I have installed a half dozen twin electric fans on these toys.. never hits 200 ever again..I removed both the old useless mechanical and small electric fans.. I made a custom shroud with venturi divider between my 2 - 14" vortex electric fans.. the car never passes 186F. Less than half mark on gauge.. also swapped temp sensors locations.. there incredibly quiet, insane amount of air circulation and runs for about a minute or 2.. now there are several companies that sell a complete kit for these cars.. but only use 2- 12" electric fans.. good luck my man.
Thanks for the info, Pete.
Great video Bob. After 25 years of same problems and meticulously maintained engine I finally fitted large HO Spal fan. Big draw on alternator and not tested in traffic in v hot weather but much better now
I like that you show “hands on” doing the work to do the work. Being a backyard mechanic it’s helpful to see it being done and your honesty about how sometimes making some fixes might add issues in the future.
You show it maybe a classic car but it can be worked on if you take your time and pay attention!
Keep the good work going, thanks it’s very educational.
1990 XJS V12 still drivable and hopefully improving as time keep going!
I have this problem with my V12 - too cold when it’s cold and too hot when it’s hot. I’ll be watching with interest!
I also have a replacement fan, and clutch, that I will soon put on, but I admit I never had much hope it would make a difference. Seemed wise to get rid of the infamous exploding yellow fan anyway.
Hi Bob - the reason for the gap in the fan blades, is to stop a harmonic from ‘humming’ when the fan is spinning at speed.
Thanks for the info.
Bob, turn the heater on full blast, LoL. I assume you did a coolant flush of the engine to wash out the passages as much as possible. Since the rad is in great condition, perhaps there is a chemical that you can run through the system, do a flush, then refill. Knock on wood my XJ6 runs cool, but next summer when she gets the V12....so I'll be following your series here with interest. When the car does get the V12, I plan on moving the clock up on top of the dash in a 3D printed enclosure and putting a second H20 temp gauge in the clock space (I have a Series 1 with the row of gauges). One for bank A and one for bank B. Looking forward to the next in this series. Cheers.
You know what they say about when we assume.😀 The coolant system flush is planned for the episode after next.
I actually had to use the heater trick on a couple of 90º+ days on a road trip to Seattle with my first XJS. I had a 24 count flat of gatorade on the passenger seat. Didn't take a pee all day. Brutal.
@@thecampchaoschronicles9567 Back in the day I rented a manual stick UHaul same thing. Brutal would be an understatement!
I think the slight assymetry you noted in the distribution (and shape) of the fan blades may be intended to avoid resonances created by rhythmically beating the air.
That was a thought I had but my son had a land rover discovery and said the clutch removal procedure included pulling the clutch through the gap. It makes sense.
Fiendishly clever these designers. Sometimes.
Much appreciated. watch all your segments on youtube.
When I got my XJS v12 it would overheat in minutes (mismatched and stuck thermostats) I replaced them both with 160 degree thermostats which works well for me since I don't ever plan to drive it in the cold.(chose such a cold temp because the idea of dropping a valve in an engine I can't afford to replace is scary...)
after three months off and on i went the homemade shroud and electric fan route....(2x mustang fans). so far...so good. both pull through radiator....which is aluminum. not cheap but worked well. took damned near 20 hours fab time. good thing i am retired and have the time to mess with such things. 🙂looking forward to seeing how this turns out for you to be sure.
Minneapolis…..I recently rescued an 1987 Lister Jaguar XJ-SC that was originally purchased at Downtown Jaguar in, Minneapolis MN already converted to a 5 speed manual for the V12. 1 family owned and only 23k. Working my way through the details to pass inspection.
Rare animal. Good for you.
An interesting vlog thanks Bob. You touched on the condition of the rad coolant side being a potential issue, it certainly was on my s3 E type as the car aged. A visual inspection of the core is difficult, did you have the flow rate/pressure drop of the rad checked by a specialist.
What bonnet vents help re more air flow around the engine bay?
Perhap but it also might upset the. original airflow scenario.
@@thecampchaoschronicles9567 hmmm. Maybe. Lol. The Combs mk2 and e types had them. (Dare I say for a reason). Lol
There’s basically no space around the v12 as u know of perhaps the latent heat build up is a partial factor….
I’d say it’s probably a few one percenters tipping things over the edge….
Have you considered this. No matter the size of the mechanical fan you fit, unless the considerable heat created by the engine can be evacuated from under the bonnet, then there is effectively no heat transfer/exchange taking place. There's only damed, superheated air with no direct path to escape. The engine and all of it's components are effectively being cooked to death within the confines under the bonnet. Cooling air needs to pass through the radiator core, absorb the heat from the coolant and then pass out of the confines of the enclosed engine bay. Appropriately placed louvres toward the rear of the bonnet would facilitate the egress of super heated air. A simple test, would be to raise the rear of the bonnet (closest to the windscreen) and take the car for a drive on a hot day.
That's why the front air dam is so important to the operation of the cooling system. My '90 convertible came without one and it ran within the N range. Then I put one on and it never got to the N and it was hotter, later in the same day. It creates a low pressure area behind it that evacuates air from the engine compartment. It's got to be there.
No qualms about the air dam, but for it to function effectively the car needs to be moving forward at a reasonable speed. When stationary in traffic for lengthy periods, then it's a different story. There's still a need to evacuate the super heated air from the confines under the bonnet, especially at the rear of the engine. Another issue of concern, is that confined super heated air will also over time destroy any plastic fittings on the engine and also harden the insulation of underbonnet wiring which ultimately leads to cracking and flaking compromising critical electrical connections.
@@enigmasvids9615 No argument there. But Jaguar shipped these things all over the empire to some pretty hot climates. Having been active in a number of forums over the years, there are people who live in places liken the southwest united states that have absolutely no problem with traffic. My '90 convertible is one of those cars. I don't know if this was a problem for the first ten years of production or not. I believe it is more of a maintenance/repair issue than a design flaw with the car.
Jaguar may have shipped them all over the world, but they certainly didn't fair well with the summer heat often prevalent in OZ. Have you sat the car idling in traffic for any length of time during a hot summer? You can further aggravate the situation by operating the car's aircon whilst stationary. Not trying to rain on your parade just listing my experiences with English cars of the period in climates that aren't as agreeable as the general weather conditions of the UK. Although the current heatwave would be something of an exception.
worn out water pump propeller ???
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