Benz300 - I also have an '88 260E that just started to exhibit the exact same problem. AC works fine, then suddenly only blows warm humid air. If I turn the car off and restart, AC works great again (for awhile).

J.HIDALGO - The belt "seems" tight (to my untrained belt-tension-testing finger).

jcyuhn - As I remove and clean, (or replace for $92.09 from PartsShop/FastLane on this site), the monovalve, should I expect a massive loss of liquid under pressure or should I expect a trickle (maybe just the amount the monovalve itself holds - like about two shotglasses full)? Do I just remove the four screws and remove and clean the cylindrical aluminum colored top cover and its internal components, or do I remove the entire monovalve unit from the two attached hoses? How do I prevent or minimize the fluid loss if it's going to occur?

LarryBible - The small fan (which seems to be behind a slotted grill that's part of the forward overhead interior light) appears to slowly inhale second-hand smoke quite readily.

dpetryk - If it's the expansion valve, is it a difficult task to remove & replace? And is this step a "last resort"?

Everyone else - I bought this car last summer and have been "lurking" and learning on this forum ever since. All the expected problems have occurred and the suggested fixes have been right on target! Maybe now I have a small amount of experience and may actually be able to become a contributor. Thanks again to ALL!!!