My step-father is the owner of a v8 jaguar S-type and recently its been overheating. he doesn't know much about cars so im trying to help him out. When I took a look at the engine, I saw that the thermostat housing was all corroded and worn out. My initial suspicion was a stuck thermostat, so I ended up replacing it as well as the thermostat housing. I filled it up with coolant to only realize I needed a bit more. I went over to the autoparts store (less than half a mile) with the car to pick up more and it began overheating again. When I came back from inside the store, I noticed a small river/puddle of coolant forming underneath/behind the back of my front drivers side tire. This now leads me to believe that the coolant reservoir tank is broken.

Now ive heard that the reservoir tank is sort of a weak link, but could this be causing the overheating issue. Doesn't the tank fail due to high heat? Im not sure if the tank is a result of the original problem

I dont really know how to define the problem other than that it overheats after driving it for a bit. My step-dad said that he actually had been driving the car by putting it in neutral, turning off the engine, and coasting, then turning it back on, giving it a chance to cool. I also know that the fans stay on after the car has shut off.

Any suggestions or advice would be appreciated. Also, if anyone knows the cheapest place to get the reservoir tank, id really appreciate it. Thanks

 

If the reservoir has a leak, the system will not fully pressurize and most certainly can overheat.

The best way to find a cooling system leak is with a pressure tester. Some auto-parts stores may rent them.

 

+1 on the recommendation

 

Thank you guys for the quick reply's and recommendations.

Just out of curiosity, how long are these tanks supposed to last. My step-dad had this problem once before, but had it fixed under warranty. that was roughly 6 years/90,000 miles ago. While im glad this tank lasted longer then the first one, it just seems a little premature. 140k and have the car run through two tanks?

Another question I have is about the burping proccess. Ive think I read on several threads that the car essentially auto burps itself over multiple hot/cold cycles. But the process is to leave the reservoir tank cap open, run at a slightly high idle (1.5k) and have the heater on blast. Does this sound correct. After I replace the tank, I don't want to have cooling issues due to air in the system.

 

The one on my 2003 S-type just let go this weekend @60K. They are not a great design, but Jag isn't the only brand with that issue.

Fill up the system, run the engine to full temperature, (turn on the heat also) then shut off the engine and let it cool. Once it is cool enough to open, top it up. After that you should be fine. Do not run it with the cap off...it will burp with it on, and boil over with it off.

 

Any good sources for these tanks? TDC, the writer of the DIY replacement for the tank claimed it only cost him $86 for the job. I cant find any place selling the tank for under 100, and most of these places are out of stock.

Also, for future reference for anyone who might stumble upon my thread with the same issue. https://www.jaguarforums.com/forum/s-type-15/diy-s-type-4-0-remove-replace-~-coolant-reservoir-tank-faq-46238/

 

Cheapest I found it was $99 + $6 shipping @ JAGUAR C2C34318 TANK/EXPANSION (Package of 1 car part), JAGUAR OEM PARTS

Old part # is XR845310
SKU is C2C34318
Searched for both of these as thats the cheapest I got.

 

$98.33 at Jaguar Parts center..usually the best price.

Jaguar Parts Center - Call (800) 510-1401 for Genuine Jaguar Parts and Accessories

I needed to get mine on the road this weekend, so I ended up paying the local dealer's markup.

 

For the part # I used to search, I stumbed accross this line for the part; "This is the latest design that eliminates the coolant sensor and stops the leak problem.". While an OEM part does sound enticing due to the fact that its original, might it be better to go aftermarket? with shipping, parts4carsonline is slightly cheaper, but I cant find any information on the retailer, and im a little skeptical to hand over over $100 to a company without much history. I think im going to end up using the link you provided in the end. Thanks

 

Yea the tank is totally going to depend on year and engine. For the STR its 150 I know the 3.0 03+ is cheaper. There are a few different tanks so that is where you are seeing the price differences.

 

I prefer to stick with the dealer based discount sites, either the one I mentioned, or Direct JPLV Porsche Parts.com.

Also Nalley Jaguar in Atlanta is 15% off list for forum members, plus free shipping. You need to call them, however.