My 1992 245 has a habit of losing coolant, as much as the whole expansion tank (2 quarts?) during a 120 mile drive. I can't see any sign of drips or smell any coolant in the cabin, carpet is dry. Has been to my mechanic's twice, and they are starting to say maybe it's just normal loss of coolant. They pressurized the system, and said it held pressure for two days. No water in the oil or vice versa. So it seems that wherever the leak is, it happens only while driving, perhaps under load. A little hard to tell because the mechanic has only the streets of Brooklyn to test drive, when the leak seems to happen more at highway speeds. Any thoughts or clues?

Thank you.

You're using coolant 1 qt/60 miles of driving? That's a lot. I can smell it well below that level. At your rate of loss

- If it's a heater core leak, you'll see it and smell it in the cabin

- If at the engine, you'll smell it under the hood after a drive

- If the head gasket into the cylinders, you'll smell it in the exhaust

No drips when you park it?

I'd drive some with the expansion-tank cap loose and see if the loss was reduced. I'd drive with the cap tight and then see if there was pressure when I cracked it.

Have you checked compression? Pull the spark plugs. If one/more is/are super-clean, suspect a head gasket.

Drive it until it warms up and have your mechanic pressure-test it hot and running. You should see/smell that kind of loss quickly.
--
240 drivers / parts cars - JH, Ohio

You may have a pinhole leak in one of the hoses that enter-exit the passenger compartment. Which only opens up when the engine is rocking.

Wrap some tissue paper around the hoses, run the engine and rock it, check to see if tissue is wet.
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.

Now suspect the freeze plugs. Some fluid shows around, not clear if that is oil or coolant. Any experiences to share?

So far I've managed to catch all of my coolant leak mysteries with a pressure test. Some need more patience than others, or the benefit of a warmed-up motor to start the leak.

Many stories told about the pinhole in the rad or rad hose which issues forth a thin fine stream of coolant only to disappear on a hot exhaust part or disperse into the air stream behind the fan. I can only suggest you repeat the pressure test and maybe apply your own patience to it. Tell your man it still leaks; could you borrow his pressure tester?
--
Art Benstein near Baltimore

Two atoms were walking down the street one day, when one of them exclaimed, "Oh no - I've lost an electron!" "Are you sure?" the other one asked. "Yes," replied the first one, "I'm positive."

A little more obvious to identify but one of teammates that is spreading the Volvo religion to his family members had not heard about the relatively common "wicking" issue with cheap or very old radiator hose. He immediately opened his hood to find and four ends of the hoses growing fuzzy green stuff.

Loss from wicking is usually measured in tablespoons per month in my experience but could be a contributing factor.

Just to add to Phil's post.

***To confirm whether the Heater Core is leaking or not. After the engine is warmed up, Turn on the heat full blast in defrost mode with the fan on. Leaking coolant will vaporize and fill the cabin with white steam coming out of the dash vents and you will smell it and it will fog up the windsheild.

Hey there man what's up with pouring that stuff in and it disappears.
Did a magician own this car before you did?
(:-) just thought I break into this almost one way conversation! The board seems a little slow lately!

If you are burning this water or coolant in the engine the spark plugs wil not have a speck of deposits on at least one of them! Steam does a heck of a good job! So well in fact, it can cause excessive wear in that cylinder including the valve guides.

Check all the plugs right away!

If you have antifreeze in the water, when that substance dries, you gotta see a trail someplace.

If it was leaking into the cabin you should, Smell it or See it, on the inside the windshield as a oily smear.
As far Feeling coolant in the carpet you might not! The coolant can run under the carpet and reside in the foam padding, which is under a rubber covering. The carpet lays on that rubber sound proofing. Get your hand under there!

If the coolant is leaking from a heater core in can be caught by a drip area under it. There is a drain hose/hole in the box that dumps condensate through the cars body, from a A/C if equipped, right on top of the transmission. Look for stains on the outside of the transmission case.

If you have a automatic, check your transmission fluid after driving so it's stirred up.

If the fluid level is on the line cold or Above the hot line, when hot, the coolant is under it!

The transmission sump shares fluid heat transfer with a seperate coil inside the radiator. Coolant is thinner than oil and the pressures can push water into the transmission. It only takes a pin hole or crack, to warmup and allow migration into the sump on long trips.

A leak pressure test will totally miss this scenario.

Hope this sends you hunting more closely because magic is not fixing this! (:-)

Phil

Does you mechanic also do inspections? Have him start the car and put the "sniffer" in the overflow, don't get it wet. High HC reading be a head gasket in your near future.

Nothing looks wet in the engine compartment? Look behind the motor, heater hoses and at the water pump. Near the cylinder head, you could have a failing head gasket. Have someone follow you to see if the car smokes out the tailpipe on acceleration. Oil, coolant and freon is like blood. If you are loosing it then there is problem and it isn't good. Good luck!