I noticed it a few minutes ago. It is hot (95 fahrenheit) today, and Dallas traffic sucks. Not sure if it does it everytime, but I will update on that in a bit because I am about to drive it. Doesn't go above the halfway point.

2002 Sport

 

The temp. gauges in these are pretty much useless it won't show a problem until it's likely too late. I monitor mine w/ Torque app & a blue tooth dongle.

 

yup fan is on after longish drives. What all do I need to check? Or is this something normal? I doubt it is normal, but not sure.

 

+1 on KC's remarks.

Same hot weather here as you experience.
The only time mine had the same problem was when my thermostat got stuck in a closed position.
Replacing it (with some other upgrades at the same time) solved the issue immediately.

I more and more think X308 owners should do a preventive replacement of the thermostat every couple of years, they are cheap and it is not a lot of work.

 

​​​​​​​Great, I can change it! What upgrades to you speak of? Car already had the aluminum thermostat housing. Water pump was replaced 2013. But I am not sure if it is the one with metal games. How can I can check to see which water pump it has? Yes, I know about reading the car's computer. I do that on my 93 Vette through and app and Bluetooth. What all is needed to do same on my Jag?

 

For peace of mind, you can easily check the old thermostat in some boiling water.
Mine clearly remained stuck, while the new one opened up when needed.

Besides of the tower, it is a good idea to replace the plastic crossover pipe in front of it, it is made of the same brittle plastic as the original tower (and it will give you a new temp sensor for free )..

If the waterpump was replaced in 2013, I should not bother too much.
Handling the plastic manufacturing process has come a long way since 1998 when some problems happened.

On the x308, the OBD2 port is in the driver's foot-well, on the right side, up against the middle console.

Not every car / make has the same output (I have one Torque configuration for our X308, and an other one for our SLK), but it is reading all important data, and quite some more.

 

Sorry, just noticed my post above had some weird words in it, like where it says games. I meant to put metal vanes.

Ok cool, I will test the thermostat Monday. If it is good, what else should I check? Also, I noticed it doesn't always run the fans once shut it off after driving. But the fans were running at high speed. They turned off after 5 minutes. Thanks for the help!

 

Well, maybe you just don't have a problem, fans are there to cool the engine, and do so if needed after shutting down.

However, as mentioned, I live in a hot, humid (and mountainous) country myself, and the fans only came on after parking up when I experienced the thermostat issues.

If I was you, besides of the test, I should get the app working on your XJ8.

It will tell you in detail what's going on in there, so no more guessing.
Check the actual value of the coolant-temp, and see if it is low after a night parked, and rises after starting.

 

My XK8 always had the fans run for about 15 seconds after shutdown if the engine was above 197 F actual temp. The fans may not have been running prior to shutdown, so I think this was programmed.

 

Thanks guys. I'll get the app and Bluetooth obd2 port to read live data.

 

Since it has been really hot this summer. My fans come on when I park after driving for quite a while. Usually for less than a minute after I park. Using torgue app and temp reads about 212. Of course that is with AC on, traffic and outside temp of 99-106.

 

Didn't really worry about because it stopped doing it. But did it to me just now. So I guess I should replace the thermostat? No coolant leaks.

 

I've learned a lot from being on the Forum, but I still haven't got my head around the cars 'brain' and how it can be changed/manipulated. Is it not possible to program when the fans should kick-in, like, tweak some settings somewhere/somehow? Please forgive me if that's a daft question, electronics is not my strong point!

I'm sure most members will remember the recent competition to win the True Temp Gauge (think that's what it was called?), are these readily available and a worthwhile MOD?

The reason I ask is that in the UK overheating is certainly not a common problem lol! So it is worth noting if settings can be 'changed' as (being so rare in the UK) any high temp would indicate a serious issue with the car's cooling system? It's pretty rare we get more than 2 or 3 days a year where the temperature reaches the dizzy height of 30 degrees C, especially in the North East UK where I live (16 C today!). Buying summer clothes is cheap though!!

 

Paul,

First of all, the X308 cooling system and controls work flawlessly if in up to date condition, and is able to control temperatures in the hottest of conditions, I can testify from practice in tropical conditions.

Problems are mainly caused by old hoses, improper hose clamps, failing thermostat, failing temperature sensor, failing plastics, a leaking pressure cap on the expansion tank, and mixed up coolant liquids.
Replace (some of) the above on a regular base, and you should be totally safe.

That said, the mentioned 'real gauge' is a nice mod, transforming the temperature gauge from an 'idiot light' into a real indication of the coolant temperature.
I think it also got an audible alarm if things get too hot.

 

Thanks guys. I'll look into this shortly. I know the gauge on the instrument cluster isn't completely accurate, but it doesn't go above half way.

 

Thanks for the clarification Eric. Where would I look to get a 'Real Gauge' for my car?

 

XK8 / XKR / XJ RealGauge - TheJagWrangler
I think forum members get discount .

 

I had a fans running-on condition with the wife's XJR last year - Plums posted a procedure for bleeding the system, which solved the problem - apparently an air gap at the temp sender for the fans if I recall correctly. The trick for bleeding is to bring the car up to temp with the system open and then put a head of coolant via a funnel on the expansion tank. As the car cools it draws in coolant until everything equalizes. Worked like a charm and no running-on since. If you think about it the fans running with nothing circulating doesn't serve any purpose except drawing the battery down. A quick search should find the detailed procedure. Good luck.

 

Thanks a lot! Yes, when I replaced the bypass hose,(near tsat tower and outlet pipe) I didn't bleed the system. Guess that could be it. I'm thinking I may as well buy a thermostat and change it, since I don't know when it was last changed. And then, bleed the system. I do know the water pump was done in 2013.

 

No-brainer, replace it, they are a cheap but crucial part!