My '84 240 DL with 137k miles runs great, but eats coolant at the rate of about a half gallon of water per 50 miles. Water pump has been replaced and I have checked to make sure there is no hint of white foam on the oil dipstick. No hint of steam in the exhaust and of course, no hint of any leaks under the hood. I have checked and rechecked hoses, etc. I'm using water because of the expense at $7+ per gallon of anti freeze. I even broke down and put some Bar's Leak in it in frustration! All to no avail.
I'm trying to get it ready for a long trip in a few weeks and all else is fine. (well, the AC isn't working and I gotta put cruise control on it...)
Any help would be greatly appreciated.
Mark
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'94 940 Wagon, '84 240 turbo sedan, '84 245 DL

I chased a leak in my 1980 245 for over one year, packing a pre-mixed jug of distilled water and coolant was part of the deal. Then one day I checked the head bolts...three were loose...I tightened them...all is lovely again. That was over three years ago. Check your valve clearances while you're in there.
Good luck, I hope it's that simple for you.

1/2 gallon in 50 miles is a lot! It doesnt appear that it is an internal leak thru the head gasket or your car wouldnt be running very well and you would definitely see coolant smoke in the exhaust. Still it might be external leak of the head gasket. You would have to see a coolant spot on the ground with a coolant trail.

You never said if you had a coolant smell in passenger area. I guess it is always possible heater core is leaking and somehow draining thru evaporator case drains. But still you should get a really strong coolant smell and coolant on ground.

If you are not seeing the leak, it sounds like you will have to do a pressure test.

Great idea!! I have a box of saltines here somewhere and I'll go out and dump them in. I assume the soggy crackers will seal the leak, right?
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'94 940 Wagon, '84 240 turbo sedan, '84 245 DL

It is leaking somewhere or it is being sucked into the engine because of a faulty head gasket. Sometimes a leak will only show up under pressure. A pressure check may be in order to help isolate the problem. A radiator shop should be able to also check the coolant for the presence of combustion gases.

Good candidates for leaking: Heater control valve, Upper radiator hose connection on radiator, heater hoses, Heater core - check to see if the carpeting is wet, coolant tank, water pump and mushroom seal.

Compression or leak-down test will help reveal a faulty head gasket.

Good luck.

Dan

Mushroom seal is ok, heater hoses are ok. Carpet dry in the cabin. Before I take it to a shop, where would I find the heater control valve? Under hood or dash?
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'94 940 Wagon, '84 240 turbo sedan, '84 245 DL

the HCV is on the drivers side just right of the gas pedal. pull off the plastic thingy that connects to the center console, it has 2 screws in it, 1 metal and 1 plastic. you will see it towards the floor. it is a metal box with 2 ports.

good luck in your search.
chuck
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'88 244 174K, '87 BMW 325e 180K (used to feed a '84 245, '84 244, '85 744)