Coolant Leak No signs

[ColorCactus]

I have a coolant leak but no signs of leakage anywhere. I suppose it's going into the engine somewhere and out the exhaust. How do I get this checked out? I have put a pressure tester on the system and the coolant level went down but no signs of leakage.

I have a 1989 300e and I went through a cold winter Angel Fire, NM., -24 degrees cold and wonder if the head got cracked and this cold be the problem.

Another part of the story is I noticed the coolant started leaking when after my overfill hose broke and I had to fit a new hose to the old hose. It was poorly done but worked. Could this effect the system?

Any help would be great. Thanks!

[Romanow]

If coolant is actually getting burned in the engine, the car will put out a lot of white smoke, Which should be very easy to see if you watch it take off. If the head gasket is leaking, It's a near certainty that there will be obvious oil in the coolant reservoir, which can be seen by the formation of a pudding-looking white mush around the rim of it. Otherwise, the same stuff could be seen on the oil dipstick.

In any case, I doubt that's the case. More likely, it leaks at the bottom passenger-side of the radiator, and only when running, so it's hard to see on the garage floor. Use pliers to bend in the metal near where the lower radiator hose comes in.

Also, replace any coolant hoses that have a swollen look, and replace the corresponding clamps.

You can message me if you want any more advice. Good Luck!

[conbobway]

I spent approx. 2 years looking for a leak that I couldn't find. It wasn't much of a leak but it seemed like every time that I added fluid up to the correct coolant fluid level, whenever I checked it, it would be approx. 1 pint low. Never had white exhaust, engine never ran hot, no antifreeze under the car, no residue on the undercarriage, hoses were dry, etc. Well, you guessed it, I had a seam leak on the coolant fluid reservoir itself and everytime that the the fluid was added and the system pressurized, the coolant would seep out slowly and evaporate.

[ColorCactus]

Thanks for the help. I've already replaced the coolant reservoir, so it's not that. I haven't done the white smoke test, because I'm currently installing my A/C system and that will be the first thing I do when I get the car rolling.
I checked the passenger side radiator hose and no moisture at all. The car leaks a good amount so, it should be noticeable there.
No residue in coolant tank, so I guess no head gasket leak. I do live in high elevation (8,000 ft). Does the elevation pressure have anything to do with extra pressure on the system?

[ColorCactus]

The answer to this question is very simple. I have a coolant line running into the windshield wiper reservoir to heat the wiper fluid. Somehow this metal line developed a leak and was leaking coolant into the wiper fluid. So, I bypassed the line outside the tank, who needs heated wiper fluid? Coolant level has stayed correct ever since. Very glad to solve this inexpensive problem. Thanks again for the help!

[Teutone]

I once had a slow coolant leak from a corroded heater core pipe (behind the firewall) dripping onto the manifold.


ColorCactus , please read the 'Welcome to the Forum' tutorial sticky on top of the W126 page.

[conbobway]

For what it's worth, I too had a coolant leak from the coolant recovery tank. In my case, it only took about three years to finally figure it out. It was always about one pint low, but after a re-fill, it would, within hours of driving, be one pint low again. It only leaked under pressure.