what's my problem?
 

i have a 1998 s320 and have discovered oil in my cooling system. no water in the crankcase oil. the car has 145k and runs quiet.does this mean a cracked head? thanks for any advice.

I can't help with your problem but you may get more response with a title of something like "1998 s320, oil in cooling system". This also helps people with similar car/problem to find your thread when searching. Also, maybe check the transmission oil for correct level and water. There is a transmission oil line in the radiator. Good luck, Dan

how much oil? does it look like chocolate milk in the coolant expansion tank? or are their some oil droplets and oil sticking to the tank sides?
Have you ever used Redline brand WaterWetter?

At 145K miles SOME say it would be normal to have some small oil deposites.

Do you know you can perform oil analysis on your engine oil and transmission oil to help guide you to whether things are normal or in need of repair.

if you query a few different phrases in the SEARCH engine at this site concerning oil contamination you'd be well versed on the issue.

Luke, sounds like a head gasket leak. Fix sooner rather than later. You should flush the cooling system to remove oil contamination.