Hello, I am trying to track down a small coolant leak on a 6 cyl XJS (95) that only happens sometimes once the car has been driven for 30 mins or more.
It doesn't leak after a short trip, or while it's just sitting for that matter.

The leak / dripping comes from somewhere above or around the radiator crossmember right up near the drivers front wheel.

The operating temp is always in normal, and we have no reason to believe the guage is not functional as it goes up and down in accordance with operation.

Any ideas where to start? Thanks

 

Lower radiator hose is in taht area.

Coolant temp switch, for the fans, is in that area on some radiators.

Top hose is the other side, but coolant is fickle, it will run to wherever it wants, just to confuse humans, so worth a look.

That year has a Plastic/Alloy radiator, I think???, and they leak at the seams.

Others will chime in eventually, but I feel a pressure test, and a good torch, and some dirty hands in your near future.

 

I've noticed the same on mine (94). Very minor, so far... I've got it up on jacks right now working on bushings, will let you know if I find anything.

Padre

 

Could be water rail gaskets.

 

Hi,


Mine did something similar due to the water pump gland seal failing. Tends to drip down onto the cross-member and then leak from there but only when engine had warmed up. Have a look to see if you have any signs of antifreeze around the bottom of the fan pulley.
Good luck,
LeeP

 

As others have said, coolant can tend to "move" down pipes etc until it eventually drips off. The rad on an XJS is prone to its cooling fins corroding and you can eventually get pinhole leaks in the lower third of the rad. The other possible cause can be any area that is connected by the multi-branch complex lower hose. So a leak at the thermostat or water pump housing can run down the length of the lower hose and then drip from the hose attachment at teh bottom corner of the rad.

Time to get under the bonnet (and the car!) methinks.

Good luck

Paul

 

Just to bump this thread. 94 AJ6 with 137k miles.

I was away for five days, come back, and there's a significant pool of coolant under the car, still dripping. From the top, everything looks dry. I recently replaced the upper radiator hose (that split).

I'll get it up on jacks soon. Any quick ideas about what would be leaking from the bottom when the car has not been driven for days?

Padre

 

It could be, probably is the water pump to water rail hose. This hose comes off the back of the water pump runs under the intake manifold to the water rail. The water rail has two small gaskets (one each end) that seal the water rail to the block.

 

That looks OK, but I'm starting to think it's a water pump gasket leak. Pretty much all the hoses I can reach/see have no coolant on them. The water pump seems moist on the bottom.

I recently had an upper radiator hose failure and watched the temps rise before I was able to pull over. I'm thinking that may have been enough to kill the water pump gasket.

Here is is from underneath:


Padre

 

Could be...? There is a "weep hole" on the bottom of the WP to show if the WP bearing seal is leaking, check that as well.