Hi everyone,

I just did oil change on my 99 SLK 230 yesterday and used a new filter kit from the dealer. After I was done, I started the engine and it all seemed ok. After running the engine for about a minute, I noticed oil leak from the O-ring. Turned the car off and dried the area. The O-ring had a bulge at the area where the oil appeared. I removed the cap and made sure all is in the right place. The O-ring seemed as good as new. Replaced and tightened the cap a little bit more that a hand-tight. Inspected the O-ring and made sure there are no bulges. Started the engine again. No leaks for about a minute, but as soon as started warming up it started tearing up (see pics).

It almost seems like it is building pressure and pushing the O-ring outward.

The only thing I can think of is that at the time I replaced the filter, the housing looked really dirty, so I used a long screwdriver and a rug to clean it up. I noticed two valves/sensor looking things at the bottom of the oil filter housing. I hope I did not damage any of them...

What are those two things and how can I test they are still functioning? Any idea why it is building pressure from the inside?

Thanks,

Rick

P.S. I used a brand new kit from the dealer - filter and O-ring. At the time of the install I made sure the new O-ring is seating right and tightened it about 1/4 turn with the wrench more than hand-tight. It looked nice and evenly pressed on all sides. After running the engine for about 1 to 2 minutes, I actually noticed an oil spot on the floor and more of a slow stream of oil coming down from a different bulge. Stopped the engine and cleaned the area with brake cleaner spray. Removed the cap, dried and inspected the O-ring, replaced the cap (1/8 turn with the wrench) and verified the O-ring is not bulging. This time I actually just stared at the area for about a minute and then I watched the O-ring deform and bulge before any oil came out. I shut off the engine right away before taking the pictures, that's why it shows just a little bit of oil. Cleaned the oil again and took another pic to show the bulge.

I will try to take more pictures from different angles and from inside the housing.

I do believe it may have something to do with the filter bypass and drain back AFAIK... I may have damage them with the screwdriver...

What effect will they have on pressure if both are fully closed/clogged up? Can they be replaced?

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