1991 XJ6 have some issues I’m trying to figure out.
Some info on the car, it uses coolant. Can not find the leak!
When driving above 65mph I can hear a squeal noise, I cannot distinguish if this is a belt slipping or coolant escaping whistle or something else?
Car does not overheat and performs well in 110f degrees and A/C on.
The needle does move in between N and H when driving above 90 mph, need to test one out more.
After the a good run the car will idle fine with the A/C on. But once I turn the A/C off the idle is very bumpy and feels like I’m in a massage chair.
When removing the coolant tank cap after sitting for a few days, it is still pressurized and will release pressure when cold. Head gasket? Cannot find hard evidence of water in oil or oil in water.
Can anyone help me diagnose my car? I would like figure out where the coolant is going? It’s not on the grounds. Car has 39000 miles on it. I’ve cleaned the throttle body and removed the air filter assembly to get a better look at the various hoses under there but I see no apparent leaks.
I have, all of the spark plugs were dry and uniform. They were pretty clean I would say. I don’t have enough experience to say they were steam cleaned, I might be in denial of a bad head gasket
First I want to know how anybody has a drivable, non collector car that’s almost 30 years old with only 39K on the clock. Did somebody purchase it new and forget it was in their garage ! It sounds crazy but I see it all the time. An average of 3.7 miles a day, and that average would get blown away with a trip to the corner market
Now where is that coolant going indeed. It’s either an external or internal leak.
With an external leak; hose, radiator, water pump, heater core, or water rail you can usually see or smell the antifreeze. Of course a very small leak may be difficult to detect but normally you can always smell it.
An internal leak, usually from a water gallery into a combustion chamber via a bad head gasket is more difficult to a detect. This exact thing happened to me last year. If this were the case you would expect the engine not to be firing on that cylinder. But this all depends on how fast the coolant level is going down. The other internal leak could be a cracked block. But with only 39,000 miles an internal leak of any kind would be very rare.
So the first troubleshooting question is … how fast are you loosing coolant?
Top off the coolant to the bottom of the filler neck and take a nice long drive. Now let the engine cool down at least several hours and check the coolant again. If the level is down and you don’t smell anything pull all the spark plugs and disconnect the fuel pump relay. Now crank the engine and look for a water mist coming out of one of the spark plug holes. Fingers crossed you won’t see any.
I purchased it from an elderly gentleman 90 years old, he purchased the car in 1994 for his retirement present with at the time only 24,000 miles on the car. I’ve already put almost a thousand miles on the car.
When driving the car, I believe I do smell the coolant when moving and the drivers window rolled down. It is 117f degrees where I’m at so I haven’t rolled down the window for any extended period of time. Only when the car is moving though do I smell it. On idle with my head in the engine bay I can’t smell it.
It’s not a lot of coolant that I’m losing. Maybe every hundred miles I would have to top it off. Need to drive it more to test this out
When checking for an external leak take the car for a long ride to get everything nice and toasty
(and with an outside temperature of 117 degrees that shouldn’t take long ) and check under the hood while you leave the engine running. A very small leak may not show up otherwise.
My guess is that it’s an external leak because unless the engine really overheated at some time in the past 39K miles is just breaking these very robust engines in.
Possibly a minor leak in the heater core? If you turn the climate control to defrost (blowers on high) whilst driving the car can you detect the smell of coolant and/ or do you see any misting on the inside of the windshield?
) and check under the hood while you leave the engine running. A very small leak may not show up otherwise.