Having worked on British cars on and off since, oh, 1975, my experience is that sometimes the best (ie it may cost more initially, but, like buying snap on (or MAC or ...???? tools, you get what you pay for..and only buy it once) solution is the OE part. Especially in critical systems on the beast.

1. It's what the manufacturer designed around, so, it's what was designed for the car
2. It will work as the manufacturer intended it to.

Other consumables (spark plugs, air filters, etc.) are generic, for the most part. Using the specific part (all things being equal) eliminates one source of 'is it the generic part I just replaced' or 'is it something else' conundrum.

Especially for things that are 'universal'...which most times, aren't.

Just my $.02.

 

Cant at all argue with that logic, but it does seem after some researc this is a Jaguar specific cap, OEM equivalent

 

. . . and does not have the 'O' ring seal to hold pressure from flowing to the overflow bottle open to the atmosphere.

 

Oh I already agreed with you its the wrong part. My local Advanced Auto has already ordered the Stant 10263 for me, should be here this afternoon. Thanks again for the advice

 

If I read your posts correctly, there was nothing wrong with the original cap.

 

I dont believe there is either, but since Im chasing down a coolant leak and the car is 17 years old, seems like a good preventative measure for a nominal sum of $$. Ive seen bad caps cause some pretty screwy cooling issues, and usually, they dont appear to have anything wrong with them, but may not be working properly. Seems like a cheap way to get some added assurance IMO

 

Got the new cap and will install once car has cooled down, but the bad news is it seems some coolant spray is again evident under the water pump, same spot we cleaned yesterday. I think I may have to bite the bullet and replace the water pump. Good news is theyre pretty cheap and I might have an indy do the job for me. When replacing the water pump, what else should I be aware of and replacing at the same time? It looks like a pretty straight forward job and doesnt seem to be connected to the timing chain, is that correct?

 

Your XJR has a shorter list than the XJ8 but I would add the thermostat and upper and lower radiator hoses to the water pump if you are going to open the coolant system up.

 

On Amazon so far, Ive found the WP, upper hose and thermostat, but cant seem to find the lower hose. Any guidance would be really appreciated

 

Am I correct that the timing chain has nothing to do with the WP?

 

Correct

 

Thanks JHartz. How likely is it that an old, now bad, coolant cap could cause a leak? I know thats something thats a possibility on most cars. Have you Jag folks seen that issue popup?

 

The only way a bad coolant cap is going to cause a leak, is if it has the pressure relief valve stuck, and the engine would have to get dangerously hot to do so.


The pressure is only there to raise the boiling point of the coolant, if you have a leak you have no pressure so can boil off some coolant as well as loosing it through the leak.


A genuine cap is only about £20, so is a cheap place to start.

 

Can't remember hearing of a pressure cap causing a leak but I guess it is possible. If the cap failed to release pressure above its rated level it would equally distribute that over pressure to the entire system to find the weakest point of escape.

 

Maybe I didn't explain myself so good, I meant exactly what you said, but as the pressure releases it can take an amount of coolant with it.

 

Again, I dont think my cap was the cause, but it was a cheap way for some added assurance on a 17yo car. An old cap not keeping the right amount of pressure can surely cause problems, even though such a scenario is likely rare. Its an old car, I dont mind buying some things here and there to keep it tip top. In the pic below, old one is left, new one is right. To my wearly old fart eyes, they are absolutely identical.

Can anyone lead me to the correct lower rad hose? Id like to buy it from Amazon if possible but cant find one. The WP, upper hose, thermostat and therm gasket Ive bought. TIA

 

U WASTED YOUR MONEY!

Bought mine from Welsh.

 

Thats great, but doesnt help. I doubt very much I payed too much, I got a great deal on all the parts so far and my personal indy is going to do the job for an incredibly reasonable amount of $$. Please, help me to find the lower hose?

 

I. bought Mine. From. Welsh!

 

Ok, thank you. I doubt I wasted my $$ if I havent bought the hose yet. Can you please share with me their website? Im new to the Jag world, not familiar with this vendor. What I like about Amazon is they stand by their product, their prices tend to be very good and I can get them within 2 days with Prime. TIA