My wife was driving her 850 GLE wagon and told me the oil light was flickering. I checked it when I got home tonight and I saw that there was oil all over the inside of the engine compartment (primarily in the rear of the compartment). I topped it off (3 1/2 qts!!), wiped it down the best I could and started it up. I heard a slight tick (gasp) coming from inside the top of the motor, and I cracked open the oil filler cap to try to hear how loud it was. There was an incredible amount of pressure when I cracked the cap open (I figured because the car was running - duh), so I closed it up and turned the car off. However, even after the car was off, when I went back to check the cap, it again really released a great hiss of pressure. First off - is that amount of pressure normal? I don't ever remember it being like that, but then I have not opened the oil filler cap immediately after turning the car off either.

Later, after I had started the car back up again, I noticed a small pool of oil gathering along the ridge on the head gasket cover (behind the oil filler), and some oil trickling down the backside of the oil filler cap's neck. Upon further investigation, there was also some fine oil mist shooting from under the cap into the back of the compartment, and as the engine ran longer, I also noted some oil trickling down the front side of the filler neck as well.

I double checked the oil level (wondered if I had added too much) but it was about 2/3 of the way between the add/fill line. Any ideas what could be causing this? Could it be that somehow the oil cap was damaged? I figure there might be some kind of damage to a valve inside (tick), but would that cause this leaking from under the cap? Any ideas or things to look at first to diagnose this problem?

Any help would be greatly appreciated....