Howdy All,

I've got a 93 245 that is loosing coolant somehow.

I've replaced both of the heater hoses. The radiator, new Volvo OE top and bottom radiator hoses, water pump, thermostat.

I can't find the leak. I've looked everywhere I can think of. I also looked very closely at the exhaust manifold for signs of a leak. The car has never overheated and runs good currently. It does run ruff for a minute max upon starting it...sometimes. Other times it starts and runs strong. No smoke of any color. No steam escaping the tailpipe.

The heater works good as does the a/c with no funny smells or fluid loss inside the car.

I live in the mountains so I've bypassed the radiator transmission fluid cooler and have added a Hayden Automotive 678 Rapid-Cool Plate and Fin Transmission Cooler in front of the radiator. I also have a "tropical" fan clutch.

Because of the changes I've done to the cooling system the car almost never goes above 1/3 on the in car temperature gauge. I've removed the temp. faker also.

It loses about 2.5 inches in the reservoir every 200 miles. I've replaced the reservoir cap with a Stant 10245 Radiator Cap - 11 PSI. When I remove the cap to add coolant I can hear the pressure escaping. I'm not sure how I'm loosing coolant yet the system is obviously pressurized?

I put my old Volvo OE reservoir cap on and it does not keep the system pressurized as when I remove the cap it does not make any noise as the new cap does. Coolant loss also happens with the OE cap.

I'm considering purchasing a Mityvac MV4560 Radiator/Cooling System and Pressure Test Kit. Before I drop $45 I thought I'd ask you guys.

Any help is greatly appreciated!

HACK

"I'm considering purchasing a Mityvac MV4560 Radiator/Cooling System and Pressure Test Kit."

This kit does not have adapters that work on the 240.
Dan

pulled the plugs today. They all look the same..normal.

Gonna have to invest in the block tester.

Perhaps there is a dye that you could add to the coolant to find the leak.

This is possibly a useful method. Just one of many videos on the subject.

https://www.youtube.com/watch?v=CHp5E7XnbXo

I see you've replaced all the things that could leak externally, it seems. You could pressurize it and watch that it holds, but I know this test can pass when things are cool and yet the HG can leak when things are fully warmed and stressed. So you might still be scratching your head after a pressure test. Might. There are those stories of a pinhole spraying a stream all the way across the engine bay where you wouldn't be looking for it.

You could pull the plugs and see if one is cleaner than the others. It sounds like you are adding a pint every hundred miles, and that's not trivial. Do you get pressure right away, or does it build only after warmed up? If you get pressure soon, consider getting a test kit for exhaust in the coolant. But that can work both ways too -- leaking out or leaking in.
--
Art Benstein near Baltimore

Those who race through life finish first. (Darrel Hunsbedt)

Thanks for the advice Art!

I'll pull the plugs this weekend and have a look.

Not sure if I get pressure right away. If I let the car sit after driving even overnight when I remove the reservoir cap there is pressure.

I think the coolant is only disappearing when the car is warmed up. But I haven't seen any on the ground. i'll put some clean cardboard under the engine and let it run a bit.

If the problem is a head gasket wouldn't the car run hot or have other symptoms?

Thanks,
HACK

My car was losing coolant and tested similar to yours. When first starting the idle was sometimes high or erratic but sometimes normal. The head gasket was only just beginning to fail. Later the cooling system was immediately pressurized on starting because the head gasket failure had advanced.

Not right away. A minor leak usually goes unnoticed until the engine overheats. I'll bet you even check your oil between changes...

I'm a little surprised you have pressure in the cooling system when it is cold. The pressure should follow the came path as the coolant and get 'lost'.

Greg

Howdy all,

Thanks for the info.

I put the original OE coolant reservoir cap back on. This cap does not hold pressure when the car is cold.

Perhaps the new non OE cap was part of the problem?

Hopefully I'll get to the bottom of this issue in the next few days. I'm going through a bunch of distilled water.

HACK