Dear XKR enthusiasts,

My 2002 XKR has a subtle coolant smell inside that starts several hours after driving. The car looses perhaps ~1/2 quart of coolant per year.
Two shops did thorough tests and could not detect any leaks.

What to do?

Thanks
SP

 

Welcome to the forum sposse,

One possibility is the Expansion Tank is known to develop minor leaks from the joint between the two halves or from pinholing in the base which only open up when the engine is hot. This allows occasional drops of coolant to fall onto the exhaust. The coolant immediately vaporises so there is the characteristic smell but no sign of a leak once the engine has cooled. A pressure test (which is carried out on a cold engine) doesn't identify a leak from this source.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

You need to pressurize the cooling system with a test kit. Pump it up and the leak will finally reveal itself....

You can borrow one (with a refundable deposit on your credit card) at many of the big box auto parts stores such as Advance, Autozone, etc....

 

I had a similar issue. It turned out to be a slight drip from the Norma connector - right side first, then later the left side. It would drip on the cat convertor and evaporate. This can be fixed, at least temporarily, with an o-ring replacement. There are many posts on this subject. I could see some orange residue on top of the cat (orange coolant).

 

I second/third all previous comments. In the XK8/XKR experience I've had, the Octopus hoses have leaked with no visible drips on floor, expansion tank issues left and right, etc. Definitely get a coolant pressure test leak kit.

I also hate to advocate extensive work, but if your cooling system on your '02 is all original (Valley Hoses, Octopus Hose, Expansion Tank, etc) you're a bad day away from failure. Best to "rip it off like a band-aid"; not sure if a shop would charge less to do it all at once since items would already be removed.

 

Mine was a torn o-ring on the expansion tank cap. Pressurizing doesn't find those.

 

^^ True, the cap must be removed in order to pressurize the system, so it is automatically out of the equation....

 

Dear All,
Thank you for your expert advice. Some additional information on the maintenance history of this 100k miles XKR convertible, which I should have added:

The smell, which is only noticeable inside the car and hours after a drive, started more than a year ago after the expansion tank were replaced to fix a small coolant leak, which was due to a crack at the bottom of the coolant tank. A few coolant hoses were subsequently replaced as well due to continuing minor leaks and the ill fitting cap of the expansion tank was replaced as well (it is still difficult to remove). Recently, I replaced the thermostat, which was misdiagnosed. The smell persisted and leak checks were conducted by two independent shops with no results. I checked for drops of coolant by placing a towel underneath the expansion tank. - negative. I am aware of potential issues with the Norma connector / Octopus hose. It is not easy to locate orange residue on top of the cat. It would be nice to see a picture of the place to check. The next step will be to rent a pressurization kit as you suggested - I may need to get it on when the coolant is still hot.

I also posted my Membership Intro as requested.

Stefan

 

 

Thanks for your concern. I meant warm, not hot. I am aware of risks.

Stefan

 

 

I performed a pressure test using a Powerbuilt test kit from AutoZone. The only adapter that seemed to fit was the #5 (for BMW). Is there a custom adapter for Jags?

When warm (not hot), it loses 2 psi within an hour. When cold, it loses 1 psi within an hour. However, I could not see any leaks - too many hoses and cables behind the supercharger. Will bring it back to the shop to have them check the valve in the butterfly hose.

Stefan

 

Everyone is talking about everything under the hood. I've had several cars with a pinhole leak in the heater core, inside the dash. It only takes the tiniest amount of coolant to give you the smell? Hope it helps.

Jack

 

my experience of the leak that was no leak and caused air in the system and sudden overheat which was not an overheat ....long story.
water pump, under it, leaked when car was warmed up only, coolant loss was minimal and no sign of it, but it smelled....water pump, so to find we warmed it up, parked it downhill and there was a puddle over night, looked up into the engine and found it was the water pump....DEFECTIVE as it was replaced along with thermostat and gaskets 6,000 miles ago....go figure.

 

Thanks all for the excellent feedback. Is there any fix for a heater core leak (other than replacing the core $$$)? I think the smell is still there when I decrease the temperature control to minimum to close the valve.
We'll check for a leaking water pump although I did not find any drops underneath the car after driving.
Could it be that the pressure test adapter was not as tight as I thought and the test result mislead me? I compared with my XJR, which appears to hold pressure better.

Stefan

 

#1 way to tell if you have a leaking heater core is if your windshield keeps developing a slimy film.

If your windshield is clear on the inside, it probably isn't the heater core, and you really don't want to change that if not needed!

 

This is where my '02 was leaking. Replacing the Octopus hose (and all the rest, with new clamps) took care of the issue.

-David

 

The coolant smell inside is now quite subtle. The latest pressure test in my trusted repair shop did not reveal any leaks. They noted that I may have overfilled the reservoir. I'll have to wait until the problem becomes more obvious.

The next item on the list is the steering wheel tilt motor, which makes grinding noises in the upper range - the auto tilt function will stay off for now. And, some times the car will not start in Park, but will start in Neutral.

Stefan