Available for free at www.jagrepair.com or here on this site.

 

Great. Thank you

 

Before loading any further expensive items in the parts catapult (Pull!), I'd suggest verifying the new thermostat and CHT sensor are accurate. Way back in post #2 I mentioned my travails. My '02 V6 was running hot, and it was a combination of a bad thermostat and inaccurate sensor. I replaced both, and it turns out the two new parts were also bad.

Since then, I have decided to always verify the accuracy of any thermostat I replace. It's super easy to do, by submerging them in a pot of water on the stove and measuring the temperature. No whining that your new parts can't possibly be bad. I've run into this enough, and thermostats seem to be especially suspect. I'd highly suggest doing that before convincing yourself the water pump needs to be replaced.

For the temp sensor, that's easy enough to check, too. See post #24 in this thread for a chart of resistance values at various temperatures, applicable to the '99-'02 V6 models:

https://www.jaguarforums.com/forum/s...2/#post1795165


It's easy enough to remove the sensor and heat it in a pot of water, too. Compare the resistance values to that chart and see how accurate it really is.

What year is your car? The '99-'02 V6 models used a different type of temp sensor than the later V6 (and all V8) models. I have no information about checking the accuracy on those cars.

 

That's a good point. The thermostat is working. I haven't checked the sensor though. Right now I'm starting to think that it Mau not be the cooling system at all. I had a similar problem in an older car I once owned. It turned out the rising temps were a result of excessive back pressure from a failing catalytic converter. I'm not jumping on that bandwagon yet but if my cooling system completely checks out it might be time to look elsewhere. My car is an 01 by the way.

 

 

It does not happen while parked. The Times that it does climb I just stop and let it idle. It eventually comes down on its own. Comes down quicker with the heat on but if I'm moving it will still climb.

 

Be careful you don't convince yourself of a bigger problem without ruling out some easy stuff first. That's exactly how my car behaved, too. The fault was a combination of the bad thermostat and bad CHT sensor, nothing else.

Also, are you using a scanner for your temperature information, or just the dash gauge? This link (same as before) has a LOT of information that should help you, especially the details of how the dash gauge is deliberately misleading:


https://www.jaguarforums.com/forum/s...rature-186873/


Oh anyways, I hope doublechecking the thermostat and temp sensor can save you some time and money...

 

Just read the thread about the same problem. Over the weekend I'm going to test both sensors and I might buy the 180 degree thermostat and test it too. My car had about 182thousand miles. That 12 degrees might help it. I'll update when I know something. Thanks.

 

New update. Tested both new and old sensors. They both tested ok. I bought a 180 degree thermostat. Tested it. It was opening when it should. Put sensor and new thermostat in. Took it for a drive. Gauge stayed right where it needed to. Thanks kr98664 for making me recheck everything. After all was said and done the old thermostat opened but way late. Now, off to the suspension. Lol. Thank you for your help.

 

Groovy, glad you got it all sorted out. Thanks for humoring me and rechecking everything.

Just curious , when you said "the old thermostat" opened too late, did you mean the original one or the first replacement?

 

It was the first replacement I checked. I never checked the original one. Drove it again this morning and it's still holding.

 

Wow! I don't know why, but there has been a rash of bad thermostats lately. Not just with our Jaguars, but I've also seen it with other brands, too. OEM, aftermarket, it doesn't seem to matter. Who knows, maybe they're all coming out of one Chinese factory but getting different labels...

 

Yeah, that's odd. You'd think they would quality test these things before putting them out.