Well, lately it seems like my car is been having one problem after another. All minor but still irritating and worrisome.

Here is the list since i bought the car a couple months ago:
1: Sagging headliner/ glove box adhesive pulling away ( no biggie fixed both)
2: Coolant housing leak(at the nipple) Ok fixed had same problem on x type ( within last month or two)
3: Diving vibrations at 70-80 ( had road forced still have problem)
4: Engine rattle when under moderate to heavy acceleration. (recent unsolved)

Here is the new problem. Recently I have been noticing the my radiator fan is kicking on alot more often than is should. The out side temp has been in the 70s and at night the 50's and it still kicks on alot at night as well.

Got home just a couple of minutes ago (out side temp 64) and the shut the car down in the garage and the fan ran for about 3-5 minutes. This doesn't make sense to me? Anything I should take a look at? When the housing tank was replaced and coolant refilled could the mechanic have used the wrong fluid and now im having this problem? I remember he said that he was going to replace the fluid with dexcool.

What do you guys think? Any suggestions would be greatly appreciated!

 

the coolant is correct, perhaps the t-stat is getting stuck? I've had to replace mine already, maybe its time for yours?

 

Is that an easy diy? Where is the t-stat located on the engine?
Also is there a easy way to tell if the tstat is operating correctly?

 

only way I have heard of, is to take it out of the car, put it in water, and heat it up...if it opens at the right temp, its good. That's too much trouble for a $50 part. I've got an extra t-stat for the 4.2 engine...it has like 2,000 miles on it if you want it (just pay for shipping). Replaced mine a few months ago, then my thermostat housing started leaking, and the new housing came with the t-stat pre-installed ($75 total).

Its pretty straightforward with the bolts and radiator hose removal. The hardest part was removing the t-stat from its 'piece' of the entire housing. Luckily, you get the entire part off, negotiate the removal of the old t-stat (and don't break its housing tabs) and putting the new one in. I found a 1" open spanner to work perfectly in this regard. Have it with you, and you'll understand why during removal.

Check out the FAQ thread at the top of the xk8/r forum, there is a PDF for the 4.0 engine and removal/replacement of its thermostat,

 

This sounds like you might have an air lock in the cooling system. You may need to burp the coolant reservoir. Someone not familar with the system could overlook this. Open the small plastic screw on the housing and let air escape from it while filling the reservoir. Other than this, you should verify a good thermostat. I always wince when a non-specialist works on a car like this, it's a crap shoot whether he will do a job right.