Radiator hose colapses...
 

The top radiator hose on my '88 300SE seems to collapse when the engine cools overnight. With the engine hot - everything seems fine. If I open the cap on the expansion tank with the engine cold, the vacuum is released and the hose expands to normal - is there a problem??

I get a little smoke on start up, but generally the car runs fine - for 250K.

Thoughts?

I would suggest a new radiator cap to start.
Dr.D

Me too! Mine would do that when I once forgot to close the cap tightly enough...so I figure yours isn't sealing properly...