Hey everyone. Odd situation and before I take it to the shop I wanted to see if there were any ideas in regard to the cause of my coolant leak.

Car is a 91 300SE with about 65,000 miles. I warm it up from time to time and last time I did, the low coolant light was on. I looked, and sure enough it was a little low on coolant (which it never is).

I pull it out of the garage and there's a stream of coolant (looked like water) left on the driveway. The missing coolant had been collecting in the plastic under-the-car-engine-bay-protector cover thingamajig (under engine) and had not dripped on the floor which is why I had never noticed a loss of coolant until I actually moved the car. No puddle until driven.

So, I refilled the reservoir and marked it with a pencil. I drove around for an hour or so (car runs very well) and when I get back the reservoir is about an inch to an inch and 1/2 low. So, its losing coolant somewhere.

I don't smell burning coolant, I checked the oil and (thankfully so far) nothing odd is in there. Coolant is also good looking with no oil or funkiness either. I checked all the obvious places for leaks, radiator, hoses - nothing. Its coming out someplace at a decent rate, but I can't see where.

So, where can I look? Any ideas where this leak is coming from? Is this a common kind of thing with the M104 or is my car a freak? I'd like to keep her, but stuff like this gets me nervous.

Thanks.