Hello Everyone!

Earlier in the year I discovered a coolant leak from the radiator, so decided to change the radiator plus all the hoses, expansion tank, and water pump. I didn't want to do any of this work again. Over the past few months another veryyy slow coolant leak developed. I couldn't find it, but today after the oil change I whip out my coolant leak detector and pressurize the system to 15 psi. Nothing initially! I was happy until I see 1 drop of coolant on the floor. I flashed the light everywhere and BINGO I find it................it was the .............coolant auxiliary pump. It was leaking from the casing!

When doing the radiator I was going to change the auxiliary pump too, but then got cheap lol

The pump was ordered and I'll swap it out next weekend.

My cheapness bite me in the butt....again. oh well

 

my aux pump has been leaking since forever

still haven’t fixed it lol

 

There are two pumps which fit our Jags:

The AC Delco one

and the rubbish one with the thin metal gasket.

I am referring to the main water pump

 

The aux water pump can be split in two and you will find an o ring between the 2 halves, that will be the cause of the leak. Mine was leaking and after about a week it would cause the water low light to come on. I was a bit concerned when it happened because I had visions of head gasket failure. But then I found the leak.

 

Oh no Joe you tickled my cheap bones...lol .. The new aux pump already arrived in the mail, but are you telling me that I only need to split the old aux pump and change the o-ring? Is that what you did and it worked?

Xalty i hear ya.. There are some things I put off for a while, but now that I know the cause I need to fix

 

I'm curious does the XJ8 also have a auxiliary pump or is it only on the xjr! I've also had a leak for a long time but could never diagnose where it was coming from as no water or coolant on the ground ever

 

Hello Doc.. I have a XJ8 NA car and yes it has the aux pump, so definitely a place to check.

I also noticed another area that could be a possible leak... While checking for leaks I noticed that there was what it seemed to be a little valley above/behind the water pump. I placed a paper towel in the "little valley" and there seemed to be dried up antifreeze (syrup texture) in there! People have mentioned that there is a coolant hose underneath the intake and it tends to fail. Could that be it??