Aarhuser

I just had this exact smae problem on my E55. Tighten to spec and the o ring bulges then pops out when I start the car. Tighten to the point just before bulge and it still pops out. Hand tighten and the damn still pops out. If have changed oil a hundred times and six time on this car, never had a problem, ever, not even a loose drain plug. As far as I can tell, there is a deficency in the cap design. It should have a slight fillet shape to hold the o ring. I am stuck. Can't even turn my car on. Been running mobil1 filters then just switched to mann and got the problem. Replaced rings back to mobil1 and still have the problem.

Benz2002

About 2 weeks ago I had the same problem. I had a bad oil leak, couldn't find it in the obvious places. The oil sensor message (the red one). the oil was a little low on the dipstick. add oil, ok for a few days, Then the oil level message comes on (the yellow one). I replaces the oil sensor , then start checking for the leak again, only to found it was leaking from the filter. The "O" ring did looked sqaushed. I replaced filter and ring.
I have been out of town so car was not driven much, I wiil check for leaks as soon as possible and see if that worked.

Aarhuser

My next idea is that oil on the ring is causing it to slip out. Going to clean thoroughly and then put back on and seal if the seal works that way. Both cap and housing are in perfect shape with no aberration or warpage so I really think it must be oil on the ring causing the issue. So weird because I have never had this problem or anything like it before.

Benz2002

Good luck, I will drive around for a while and check mine again

BBBSS

The part about it gaining you .5 in the 1/4 made me think your just screwing with us now. Or at least I sure hope this was all a joke otherwise..

06E55

My wife had this happen by the dealership at her first oil change on her 09 C300. An o-ring failed and we had oil everywhere...

MBTEK

The problem you describe is from install error,there is an upper groove right by the top of the filter cap,and one a little lower.The seal goes on the lower groove, not by the the top.I have seen more than 1 engine leak/destroyed by that mistake,just recently a new ML CDI that went 6k miles after an oil change at another dealer befored towed in for engine failure.Pay attn. to seal install,lightly lube and tightened cap slowly till tight and you'll have no more problems.

izzyz28

I've been putting it on the upper groove since I got the car(about 7 oil changes, that's where it was when I bought the car) and I guess I've been lucky so far. It certainly seems like that's where it's supposed to go, but from the pictures I just looked at I can tell that you're 100% correct. Thanks!

Yuille36

The oil filter comes with the rubber o-rings for a reason, use them. Not using them, doesn't make any sense to me. The large o-ring needs a little oil to lubricate them, before tightening the oil filter cap. This is simply user error period.

Aarhuser

Problem solved. I accidentally installed a new o ring over the old o ring that was flattened against sthe plastic and blended in perfectly. I must have done this on the previous oil change, but it didn't cause a problem until this time. I had been running 8k with two o rings in the same spot and no leaks. Completely ridiculous! I've had my dumbass moment for the week.

roguewrester

Same thing happened to me on a Sunday morning out in Selma (california) in the middle of nowhere. Oil Filter failure. oil all over the front of my engine. I freaked out until I called my best friend (MB mechanic) and described what UI saw and what happened. He knew right away what the problem was without seeing it and said that its a fairly common thing for the filter to fail. Had my car towed to Fresno (25 miles away) and found the only place open that I could get an oil change done was a Firestone. Walked the guy thru it and have had no problems since. I think I need to replace my sensor though. Everything looks good with levels and no leaks but I occasionaly get the "check oil level" light.

Aarhuser

figured out the issue with mine. the o rings on the oil filter housing are usually orange to distinguish from the black housing. however I bought some filters with black ones. 1 of the rings, the main 1 at the very top got smashed flat into the groove and I didn't realize that I put the new 1 over the top of the old 1. remove the old 1 problem solved.

msheredy

I've seen this happen on the V6s (320s) as well. It's either that the filter wasn't tightened enough or the large o-ring wasn't installed correctly. The o-ring sits in it's own channel maybe an 1/8" below the lip of the filter housing. If the o-ring is bulging out it's probably because the o-ring was installed just below the lip which is incorrect.

Oil all over isn't fun at all to clean up because it's a gift that keeps on giving. It'll take you a few rounds of cleaning till it's all been dispersed from the nooks and crannies.

daouu

I have the severe leakage until I think of a way to tackle it. I went to Homedepot and buy an air vent clamp (the diameter of the adjustable clamp is betw 3-4"). I put the clamp around the oil ring and tighten it, at the same time I tighten the cap. That's way the o-ring does not bulge oưt when you tighten the cap. I think the problem is solved.
I know it is the design issue. The should chamfer the cap and the bottom aluminum housing and/or the O-ring must be tough and does not stretch and/or the sectional circle must be smaller.

Yuille36

Could the o ring have gotten pinched somehow. Did you lubricate the new o ring with some engine oil before re-installation?

tw2

Replace o ring, lubricate all of them as mentioned above, carefully install in the correct groove and if you are **** like me then get the torque wrench out so there is no room for error.

Redwood415

When installing the new O-rings, always lube up slightly with clean oil, when you install the new ones dry they can twist or bind up when you crank the cap down. I had this happen to me on ML (M112 motor)
since that day (10 years ago) I have always done it the same way and had zero issues, lastly torque cap to torque spec, its there for a reason. - Cheers

daouu

Yuille36, lubricating or using the dry/brand new O ring still did not solve the problem, until I used the cheap clamp as described above. I bought several filters made by Bosch/Mann (Made in Germany), took the O rings and used them, and still had the leaking issue. The clamp is cheap and you might need some thin metal at the screw of the clamp to press in all the lengh of the O-ring.
I believe that the O-rings (and filters) I bougth on Ebay and Autozone are good.
Don't know the OEM sold by dealership is any better.
Good lucks.

daouu

As I said in my case, the edges of the cap and the filter body are smooth and have no damages or chips. But when I tighten the cap, the O ring always bulges out and the leakage was severe. I do hope the O ring is smaller in diameter and smaller in sectional diameter so it can not bulges out under pressure.
But using the $2 clamp solves my problem.

daouu

just a blank

daouu

Also my belt idler was broken and I think the leaking oil that wet the serpentine belt caused the problem. So you guys have to fix the oil leakage at the filter cap before having trouble with the serpentine belt.

tw2

Sorry but I think there must be something wrong with your filter housing or filter assembly. What you describes does not sound like a good fix. I would check the metal housing very carefully and order a replacement assembly (the black long plastic thing) as they are not too expensive. I presume you also have the correct filter socket for a wrench.

daouu

tw2,
I inspected and found nothing wrong except the seat for the O-ring is too small and when you screw the black cap to the aluminum filter body the O-ring gives out.
I have been exremmely happy to do the makeshift fix as described above!

StarvingArtist

I haven't read the whole thread, but all three of mine will seal hand tight, and there's enough resistance in the o-ring to keep it from unscrewing. Seems like you're not in the proper groove. move the o-ring one notch deeper. It should be in the housing and past the inner bevel a few turns before it's tight.

E63007

As embarrassing as this is, I have to thank you for pointing this out!! After rebuilding my engine and having done several oil refills and after having just installed a new Radiator and A/C Compressor, I missed the fact that there was already a black rubber O-Ring in that particular groove, however, my filter came with a White O-Ring and I ended up slapping it on there without taking the old one off and sure enough, I have noticed an oil leak that I traced back to the damn filter!! After reading this, it was obvious what the problem was!! The white O-Ring was remaining on the outside being squeezed such that it would visibly come outside the circumference of the Oil Cap. I had remembered someone saying to only tighten hand tight, so I did, only to result in this mess, only its not all that bad. It does explain my misunderstanding that it might have been A/C Oil leaking from the lowermost bolt!!!!!

So after just reading this, I go and remove the Oil Filter Cap and saw that there was already a Black O-Ring there, so I removed the White O-Ring and now the Cap tightens as it should! Sweet!!!