Hi,

My 1990 760 GLE (V6) with 220K miles has started to lose coolant. No eternal leaks are visible but steam comes out of the oil filler cap. What are the symptoms and how expensive to fix? The car is otherwise in excellent condition and I would hate to send it to the junk yard.

Thanks in advance for your feedback.

Have you done an oil change lately and note any unusual coloration of the oil..perhaps leaning towards "coffee with cream color" .I also experienced coolant loss even though at a very slow rate ..no dripping on ground. As it turned out there was a hairline crack on the upper plastic "cover' of the radiator just BELOW the upper rad. hose and so was not easily visible from the top. My attempt to fix this resulted in a crumbling of the plastic and subsequenr removal and replacement with a new heavy duty all metal type radiator...good luck

I believe this is an aluminum engine with wet liners (sleeves) so I think repairs would be very expensive.

Try the old truck drivers trick of one or two tubes of "Alumaseal" and remove all pressure from the cooling system.

You got nothing to lose at this point! Try it!

Of course you always replace the engine with a trusty "red block"

Sounda to me like a blown head gasket, if youre sure its steam comming from the top of the engine then youd better not drive it as oil and water dont mix well in an engine, now its highly possible you blew a section of gasket and are only throwing water out the tail pipe, i did this on a few 700's, easy fix on that car, but a good time to get the hear machined and valve;s done, do a quick compression check to see if any of your cyl's are off.

I meant external not eternal :)