I posted a message about my occasional droning radiator fan(s) and it was suggested I change the thermostat 'pronto' as my car shouldn't be over-running the fan when turned off, particularly with the flippin' cold weather we've been getting.
The odd thing is, the gauges don't indicate any kind of overheating.
It says all is well, nice and in the middle.
Any ideas?

Roy.

 

The temperature gauge is notorious. By the time it moves to indicate overheating, engine temperatures are already way too high.

The only reliable way to determine operating temperature is with a scantool such as AutoEnginuity which gives the actual temperature.

Graham

 

The temp gauge will not give you an acurate real time reading. they are rigged to stay in the middle. This is a well known feature which jaguar thought was a good idea. Problem is, if a problem devellops, it can be too late to react.
Not only should you change the thermostat, you need to inspect the water pump which i think you will find the plastic fins have disintegrated.

 

The only gauge on the xk that works is the clock and speedo.if you continue to drive and it overheats...good chance you may have valve seats dropping on the pistons.heads warping..blown head gaskets..all mega bucks..the thermostat is a very very easy job to do..cheap..water pump also cause problems..not trying to frighten you..jusy good advice

 

The car had a Jag replacement engine only 35,000 miles ago and it's as sweet as a nut.
I really don't want to risk anything, so I think I'm going to replace the water pump and thermostat at the same time anyway, 'just in case'.
The parts aren't particularly expensive and I have an excellent mechanic who charges almost nothing for his time.
For example - a brand new genuine Jaguar XK8 steering rack, fitted, flushed and filled, PLUS replacing the anti-roll bar bushes, £370 ALL IN!!!!
And yes, it was a GENUINE steering rack - I had it delivered to my address.
All packaging, paperwork, part numbers etc were correct.
And it wasn't a re-furb unit.
Marshall Jaguar in Ipswich wanted almost £1100 for the same job, not including roll bar bushes!!!

Roy.

 

This thread discusses how the temperature gauge works (or rather doesn't): https://www.jaguarforums.com/forum/x...e-gauge-62813/

I have developed a 'black box' that converts the existng temperature and oil pressure gauges to real, functioning gauges. Currently it is undergoing beta test with a couple of forum members and I expect to have it for sale on my website (below) later next month.

 

Don’t know what series you’re asking about but in my own research the service manual I downloaded from Jaguar (X350) says the electric fan running for 4 minutes is “normal” so just thought I’d post that.

 

I'm having this same issue - going into the shop Tuesday to check it out. One question I have is if it's truly damaging things running this way, wouldn't the temp Guage actually just climb into the red like it's designed to do? I know it's basically an prettier idiot light, but if it appears to be functional (slowly climbs to midpoint and stays there) why wouldn't it shoot to the red?

 

The gauge reads mid scale until about 230 deg, then climbs rapidly. The X350 fan may be expected to run for four minutes, but I don't think that applies to the X100.

 

Maybe they changed something over the years, but fan running after ignition shut off is normal. I remember reading factory warnings not to stick your hand by the fan in case it happens.
Mine typically does this after driving with ac on on days in upper 80s farenheit.
FWIW I have the real guage installed, wouldn't want to be without it, so I can attest to fact that it has nothing to do with overheating. Fan running ignition off, typically happens when temp is up around or above 200ish.

John

 

My 97fan used to run for about 15 sec after ignition off on a hot day, my 06 hasn't done that yet.

 

I had an issue with a different model. Could not stop it from over heating no matter what I did to it. It turned out that it was a leaky radiator cap not holding pressure....... Might want to replace your cap. It might be your problem, and is a cheap try.

 

Has anyone had this coolant leak problem? I'm baffled.

I drive a 2002 XJ8 Sport. I can drive it all day long around Los Angeles freeways in traffic or fast moving without loosing any coolant. When I drive into the mountains to about 5000 feet altitude and turn off the engine about 10 seconds after shut down coolant pours out onto the ground from the overflow tank. Then I get the low coolant message. The car was not overheating. I replaced the pressure cap but the same thing happened on my next trip up the mountain. I've replaced thermostat, pressure tank, cap, and water pump. I test drove it up the mountain today with the same problem. I start the car back up and it stops leaking. I drove it home and turned off the motor with no sign of overflow. Can there be a problem having to do with the altitude? The only other thing about that altitude is that its cold and may be the only time the heater is activated.

Any thoughts are greatly appreciated!