Took my 1997 XK8 out first time this season and ended up overheating. Never happened before. Planning to start with the thermostat replacement followed by the housing replacement. I know I would be doing certain things twice but seeing how much PITA the housing replacement is, I want to make sure it is a thermostat issue. Could someone please confirm that these are the correct parts:

https://www.welshent.com/Heating-Coo...at-With-Gasket
https://www.welshent.com/Heating-Coo...ing-Kit-P22770

Also, is there a way to test the radiator fans and associated relay?
Any other recommendations are welcomed.
Thank you.

 

If the T-mostat housing is original, then it may crumble or the brass thread inserts come loose?
Might plan on that as well as the cross-over pipe.

The original water pumps (nylon 66 impeller) were known defective as the impeller would detach from the shaft.

 

Thank you for the response. Would this be the correct part for the cross-over ?

https://www.autohausaz.com/pn/639_20...caAo_fEALw_wcB

How about thermostat and housing in my 1st post? It looks like a perfect match, but wanted to double check.

 

The housing description includes the thermostat. No need to purchase a separate one.

The cross over looks good.

 

Thank you, ordering the parts. I am sure it will be an adventure as anything that is not metal under the hood falls apart as soon as you touch it.

 

I usually spray cleaner and blow debris from the intake-to-head area then loosen/remove the intake 10 M8 bolts.
Leave the throttle area M8 bolts to 'pivot' and lift the front of the intake 'slightly' to access the rear T-Mostat base bolts.

I bought a pack of shorter M6 x 1.00 x16mm Allen socket head bolts to replace the factory bolts in case I need to replace the tower gaskets/seals in the future.

Long enough to hold the tower but short enough to get out in the tight confines of the manifold.

Bolt the intake back down. Never had one leak but it is possible as you are re-using the rubber intake seals.
Clean head/manifold surfaces should re-seal.

 

Understood, thank you. There are also some recommendations to use 8mm open wrench that is bent 90 degrees or a crowfoot. Will see what works.

 

The people that recommend using a wrench to remove the rear base bolts usually end up breaking/destroying the plastic housing to get enough clearance for the bolt removal.

Never tried it, I just lift the intake.

 

Just so that I understand, breaking the housing is not an issue if it is being replaced anyway, correct? Or are you referring to something else?

 

When I replaced the housing in my '97, I stuffed a rag in there and broke it apart, then used socket head screws and a ball drive on the aluminum housing. Just make sure you get all the pieces out.

 

Thank you, parts are ordered ...

 

make sure you get an 82 degree C thermostat ..gives you a heads start and I run the fans half speed 24/7. Its only one wire on the ecu plug to earth and does not affect the full speed . If you look at my posts I have written it up .

 

already ordered the parts, but will take a look at your thread, will have to re-order if i go this route

thank you

 

Replaced the thermostat, crossover, and temp sensor ( i am assuming that is the sensor that is mounted on the crossover). Still overheating plus I get no temp indication. The hose that is coming from the thermostat and going to the passenger side of the radiator is hot, the hose that is coming back from the driver side radiator to the top of the thermostat housing is not. Water pump? Completely clogged radiator?

ty

 

Most likely it's the pump.. If you can read the part number printed on the front of the case, it'easy to know if it's the plastic impeller type.

 

Could someone recommend a good mechanic in Northern NJ. I had good experience with Marotas Motors but lately can’t get a hold of him.

thx

 

No temp indication - You might check the temp sensor.
When I replaced the thermostat housing, which came with a new sensor, it was bad.
Overheating on the first test run after finishing the job.
Replaced sensor with the old one, temperature gauge working again and no more problems.

Good luck.

 

With a bad sensor it's possibile that the engine management didn't turn on the fans.
But in his case the water doesn't circulate, the thermostat, if it is working, must open anyway, even with a bad sensor.

 

If it does not circulate after the thermostat replacement, wouldn't this be a pump? The fact that the other hose does not heat up makes me think that there is no circulation.

What if I remove thermostat all together and do a test run?

I am not that great with the engine troubleshooting, but I do have decent troubleshooting skills. I think temp sensor is a secondary issue, I will sort it out once I get the main issue resolved. I dont get temp indication with either old or new sensor. So it is possible a connector or a wire issue, everything is so brittle under the hood, it is crazy.