My 1994 E420 had a front crankshaft seal leaking a decent amount of oil. I have since had the seal replaced, yet there continues to be a strong odor coming from the engine bay. I notice it when parking in my garage, or while at a stoplight. I assume that some residual oil is on the manifold, or some other hot engine component, which "activates" the smell after driving for a while. Will a thorough steam cleaning take care of the smell? Any precautions with steam cleaning that I should be aware of? Most detail shops have stopped offering steam cleaning due to EPA restrictions. At one point I tried an engine degreaser and a garden hose, but it did not do anything for the smell.

Thanks a lot in advance for any helpful replies.

You may have other leaks. Make sure that the valve covers are OK and that the tranny is dry.