V8 "Engine Overheating" displayed in message centre?
Discussion
Hello all, first post...
Late-model XKR.
After 10-15 minutes sitting in slow-moving traffic, the dashboard displays the disconcerting news that the engine is overheating.
Is this standard fare, because there's no temperature gauge, or is it a signal of impending doom?
I understand these engines are pretty bullet-proof, so could it be a dicky sensor, or something more fundamental?
Would a dicky sensor "show/not show" on the diagnostic memory recall?
Thanks all, in advance.
Late-model XKR.
After 10-15 minutes sitting in slow-moving traffic, the dashboard displays the disconcerting news that the engine is overheating.
Is this standard fare, because there's no temperature gauge, or is it a signal of impending doom?
I understand these engines are pretty bullet-proof, so could it be a dicky sensor, or something more fundamental?
Would a dicky sensor "show/not show" on the diagnostic memory recall?
Thanks all, in advance.
It is VERY serious! You have an Aluminium engine , they don't like getting too hot. Typically the fault you describe is either a failing thermostat or fans. Simple first check open the bonnet are the fans running with the aircon on? Might just be a fuse blown? Don't wait, head gasket failure follows after an overheat, the solutions are much cheaper if you find the cause quickly.
I appreciate the reference to the radiator fan - and aluminium engine design.
What puzzles/intrigues me is whether or not a failed fan would register in the OBD memory - given that it's such a fundamentally important engine protection feature.
And, if it doesn't log a fault, then the only means of "testing" would be going down the "destructive testing" route, and creating a situation whereby you necessarily have to overheat the engine to notice the failed fan? Though this does seem a strange way of going about things.
Thank you to all who have contributed.
What puzzles/intrigues me is whether or not a failed fan would register in the OBD memory - given that it's such a fundamentally important engine protection feature.
And, if it doesn't log a fault, then the only means of "testing" would be going down the "destructive testing" route, and creating a situation whereby you necessarily have to overheat the engine to notice the failed fan? Though this does seem a strange way of going about things.
Thank you to all who have contributed.
I have an XF, 5.0 V8 n/a. Recently, I got a yellow engine warning light come on. Took it to the local JMD and it was diagnosed as a failing water pump which is quite a common issue after around 50,000 miles with the XF, apparently.
I mention this because the warning light relating to the water pump is not the same as what's appeared on your vehicle, so maybe a water pump failure can be eliminated in your case.
R.
I mention this because the warning light relating to the water pump is not the same as what's appeared on your vehicle, so maybe a water pump failure can be eliminated in your case.
R.
The Leaper said:
I have an XF, 5.0 V8 n/a. Recently, I got a yellow engine warning light come on. Took it to the local JMD and it was diagnosed as a failing water pump which is quite a common issue after around 50,000 miles with the XF, apparently.
I mention this because the warning light relating to the water pump is not the same as what's appeared on your vehicle, so maybe a water pump failure can be eliminated in your case.
R.
Can I ask what warning is displayed for that, please? I mention this because the warning light relating to the water pump is not the same as what's appeared on your vehicle, so maybe a water pump failure can be eliminated in your case.
R.
Just curious, without sounding daft - is it a specific message?
a8hex said:
Don't thermostats tend to fail open?
That's been my experience, although not on a V8.
The symptom is the heater doesn't work and even if you have a pre-heater so you leave home with the heater blowing nice warm air, within about the first 100 yards is back to blowing cold again.
Jaguar 4.0 and 4.2 V8s tend to fail closed That's been my experience, although not on a V8.
The symptom is the heater doesn't work and even if you have a pre-heater so you leave home with the heater blowing nice warm air, within about the first 100 yards is back to blowing cold again.
P700DEE said:
a8hex said:
Don't thermostats tend to fail open?
That's been my experience, although not on a V8.
The symptom is the heater doesn't work and even if you have a pre-heater so you leave home with the heater blowing nice warm air, within about the first 100 yards is back to blowing cold again.
Jaguar 4.0 and 4.2 V8s tend to fail closed That's been my experience, although not on a V8.
The symptom is the heater doesn't work and even if you have a pre-heater so you leave home with the heater blowing nice warm air, within about the first 100 yards is back to blowing cold again.
What ever happened to fail safe design New Relic said:
How did it take a week to repair :-O ?
And, may I ask how Jaguar diagnosed it?
It was originally diagnosed at the roadside by the AA man that Jaguar sent out. I can't say I remember what he actually did to diagnose it though. He advised me it would be OK to drive the two miles home as I'd been stopped for over an hour. Jaguar then sent a low loader to collect the car and left me a brand new Discovery to use. This was on a Thursday night and they didn't actually get to look at it until the Monday. Then once they'd confirmed it was the fan they had to order the part in, fit it, test and so on. I think it was actually eight days in total before I got my car back. I wasn't overly bothered as I unexpectedly enjoyed the Discovery.And, may I ask how Jaguar diagnosed it?
P700DEE said:
It is VERY serious! You have an Aluminium engine , they don't like getting too hot. Typically the fault you describe is either a failing thermostat or fans. Simple first check open the bonnet are the fans running with the aircon on? Might just be a fuse blown? Don't wait, head gasket failure follows after an overheat, the solutions are much cheaper if you find the cause quickly.
Rhetorical question, but when does "overheat" become a "serious overheat" which would cause significant latent damage ?I hope the question doesn't sound absurd.
TIA
Based on the earlier 4.0 cars which had a damped switch as a temperature guage it was possible to damage the head gaskets from a single event where the switch activated the red over temperature warning. The 4.2 gaskets were much better, I lost all my water in my 4.2 S type on the M5 and unknowingly continued my journey for five miles without water before the over temperature light came on! My car was recovered, valley pipe failure re filled and is still running fine now some two years later and 20k miles. I have no experience of over heating a 5.0 but Aluminium engines are far more likely to warp than steel. The temperature warning light is a RED stop engine as is the low water warning. From my limited experience I think these warnings are worth investigating sooner rather than later.
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