Hi,
Been topping up the coolant far too frequently over the last few months. Only small amounts originally, but I am now topping up the reservoir daily, only small amounts, but it is going somewhere. Have yet to spot any leak, ive looked for areas such as thermostat body and water pump. ive looked at the reservoir, no leak. pipes look in good order, no trace of any leak whatever.

The engine runs great, no sign of water in the oil. Never seam to get heater more than warm though.

Any Suggestions appreciated.

Steveeasy

 

I have a small leak in my 97, most likely at the firewall. The evidence is only visible from underneath the car. I suspect the octopus hose where it connects at the firewall. It's on my to-do list.

 

Steve,

Are you finding coolant on the ground beneath the engine? Where?

If you don't top it up, will you get a Low Coolant Level alert?

I've been chasing down an occasional whiff of coolant smell and I think it may come from my expansion tank (in the fender well) when (if?) I over-fill the reservoir. Of this I'm not entirely sure, but my next "action" is to do nothing. I'm not topping off the reservoir again UNTIL I get a low coolant alert.

Hopefully this experiment will go on for many "years" - lol. Well - at least TWO!

BTW: I recently had some kind of mysterious coolant disappearing act that went on for several hundreds of miles. It was the water pump (at 85K miles). It took quite some time before I found evidence enough to point me in the correct direction for a fix.

Good luck to you and yours.

 

Hi Jim & Glen,
Thanks for your feedback. I get the low coolant level warning as soon as the the level drops off, I then add 200ml of water that fills the reservoir.

I am not finding any coolant on the ground under the car at all. I think im going to have to look again, perhaps I need to run it up to temp and then look.

steveeasy

 

Hi Steve,
Had the same problem on mine, turned out I only needed a new hose clip. It was a pressure test that found it.

No coolant on the ground and no tell tale signs in the engine bay.

May be worth getting the system pressure tested. If the car is only just getting warm inside then it could be a sign of a stuck open thermostat.

Hope this helps,

Jim

 

was having the same issue... tighten the line from the coolant reservoir to the thermostat housing or even replace the clamp with a screw down type... if it leaks there you wont notice it because it wont start untill under pressure and then is so small it evaporates as soon as it hits the tower that is now hot . my light was coming on every other day add maybe half a cup and full again

 

I concur with doing a cooling system pressure test. I chased an invisible micro-leak for a month until I got tired of adding a couple of ounces of coolant every weekend and borrowed a pressure test kit. It quickly proved that the culprit was the thermostat housing. The small amount of coolant that was leaking would evaporate off in the hot engine bay before it could stain anything that I could see. I replaced the entire plastic coolant duct assembly (including the thermostat and its housing), the brittle plastic hose running between the top of the coolant duct assembly and the coolant expansion tank (and installed new worm-drive clamps), and all was well again. That was about 45 days and 2,000 miles ago and I have not had to add a single drop of coolant since....

 

Hmmm, ...... 200ml sounds about right for the warning level.

OK. If you're only replacing the lost coolant with water that may be the problem, or at least part of it. The overly diluted coolant may just be evaporating in the expansion tank. After shut-down, when the cooling engine looks to inhale some of the expansion tank fluid back, it's not there. So less is returned to the engine than was expanded away while it was running. As this cycle continues the reservoir level steadily drops. The situation also worsens as you keep adding just water to the reservoir when it's low.

Do they still even make "hygrometers"? Using one of those would tell you if your coolant is diluted. Try adding straight concentrated coolant (not 50/50) for a while and see if it makes any difference. Don't worry about using too much - I've successfully limped a couple of cars home with taped-up hoses by running 100% concentrate and leaving the radiator cap off (i.e., depressurizing the system).

 

Hi,
Good Points, ill get a pressure test done, ill also add coolant and see what happens.

steveeasy

 

+1 on all advice, also recommend looking just under the throttle body, there is a plastic 3-way connector connecting 2 small hoses and the octopus hose that has a tendency to crack causing small leak - just replaced mine a few weeks back - $3.00 part that fell apart when I started disconnecting.

 

Front end is off my XK8 and before, I would have to put maybe a TEA CUP of coolant in about once a month. I found that somewhat manageable but still was curious where it was getting out. I could smell a light 'burned coolant' smell after short rides and couldn't find the leak.


With the front end off for a restoration of the front, the body shop was drawing DOWN the coolant system to put new in and it wouldn't hold. They found the slight leak IN FRONT OF THE aluminum THERMOSTAT HOUSING that I upgraded to a couple off years ago. I retorqued the bolts and hopefully that solves my leak.


I would have sworn that the leak WAS NOT AT THAT LOCATION but.....was wrong!!!


Check yours again and the 'octapus' hoses up at the firewall is also a likely source.


Good luck.

 

when my water pump was leaking it was just a little, it burned off and I never saw it but smelled it, then one day it sat, cooled down and I saw the dribble of fluid from it.

 

Exactly how it played out for me a few months ago. Once the failing pump actually announced itself, I was adding coolant every few days and it was worsening quickly too. I was down to getting a low coolant warning every other day by the time I changed it out (about two weeks later).

BRG: How far did you push yours?

 

btw can rent a pressure test kit from orielys for nothing just a deposit that is refunded when you bring it back am sure autozone and other places have the same .

 

Not all pressure test loaner kits are created equal. The kit available at my local Autozone did not have the necessary adapter to fit down into the coolant reservoir tank and seal properly. The kit available at my local Advance Auto Parts had far more nozzles and adapters (including the one that I needed) so I went with that one. Be sure to carefully check that kit before you take it home. The more various and sundry pieces in the kit, the better chance you have of finding the correct adapter....

 

I have 'rented' pressure test kits from both Advance and O'Rilley and never found a fitting that matched the Jaguar reservoir. Always had to use the 'universal' cone shaped fitting which worked without a problem.

 

Hi Steve:


I experienced a similar problem recently with the low coolant warning light and I could never find any leaks in the engine compartment or underneath the car.

I had a coolant system pressure check done and found the problem. The rubber O-ring on the bottom of the coolant filler pressure cap was not sealing properly because of an aging part, which allowed very small amounts of coolant to bleed past / around the pressure cap. I guess the high engine temperature simply burned off the coolant. Thus, no visible coolant traces or smell in the engine compartment.

The problem was solved with the installation of a new pressure cap. Worth checking since it is a minor repair -- if the pressure cap is the problem.

 

I would check the valley hoses under the intake manifold. You cant see them, but I too smelled coolant and forever could find no leak. So one day I'm detailing the engine, look down and the valley shows signs of having coolant where it shouldn't be. Sure enough, valley hoses. There are tons of posts about them on here. Not a cheap date.

 

Hi,
update, not managed to do a pressure test as yet. While driving today, the amber warning light came on, never been seen before. and at the same time the temp dropped to cold, lasted two minuets and everything normal.

I think its time I checked the water pump and thermostat.

steveeasy