That's oil you need....

[Mactech]

I was up in the lake district at the weekend (should have taken a boat not a car) but on the return journey my S class disgraced itself.
We stopped at services lunchtime yesterday and the engine undertray was dripping with engine oil
No warning messages, no function changes just lots of oil! Popped the bonnet and it was obvoius that the oil was coming from the oil filler cap. Removed it and checked the seal and all seemed ok, except the oil was everywhere.
Took it to the dealers this morning and they cleared up the mess and replaced the cap. ' We have seen this on a brand new car' was their comment. I had visions of blocked breathers or crankcase over pressure but they assured me that if the cap seal fails, this is the result. This is my first Mercedes issue in 5 years. Anyone else had a oil filler cap fail?

 

[KLP 92]

I've had a few that seep a bit of oil but nothing that excessive!

 

[mikevernon]

I was up in the lake district at the weekend (should have taken a boat not a car) but on the return journey my S class disgraced itself.
We stopped at services lunchtime yesterday and the engine undertray was dripping with engine oil
No warning messages, no function changes just lots of oil! Popped the bonnet and it was obvoius that the oil was coming from the oil filler cap. Removed it and checked the seal and all seemed ok, except the oil was everywhere.
Took it to the dealers this morning and they cleared up the mess and replaced the cap. ' We have seen this on a brand new car' was their comment. I had visions of blocked breathers or crankcase over pressure but they assured me that if the cap seal fails, this is the result. This is my first Mercedes issue in 5 years. Anyone else had a oil filler cap fail?

I had a similar problem last year on my old 911 C4 (964 model) just before I sold it. I hadn't used it over the winter and it developed all kinds of electrical problems while standing outside, mainly caused by a serious water leak into the cabin. Eventually I sorted it and took it for an MoT which it passed, so on the way home I opened it up a bit. A few hundred yards from home I noticed an enormous cloud of smoke in the rear view mirror, so I limped home at 10mph with a trail of oil pouring from the engine bay and feeling utterly dejected.

When I opened the lid the whole engine bay was drenched in best Shell Helix which was dripping all over the exhaust and my driveway. The filler cap was resting on the undertray, so I must have failed to replace it properly when topping up. I jetwashed the engine but it still stank of hot oil for weeks afterwards, and I had a terrible job convincing any potential buyers that it didn't suffer from the usual oil leaks for which the 964 is justifiably renowned.