E90 reality question

[Oldmactech]

Son has a 07 335i twin turbo that leaks oil like crazy, not just a drip but a puddle the size of two basketballs every time he parks. Had oil filter housing gasket, valve cover gasket and oil pan gasket changed, no joy. We suspect rear main seal. Talking to a repair guy today and he said probably the entire oil filter housing leaks not just the gasket. Theory being the oil pressure at that point makes it leak more dramatically. Fairly common at 90k miles he said.

Anyone want to chime in?

thanks.

[marvinstockman]

Clean engine, buy UV dye kit, dump dye into oil, UV light will find leak.

[White94RX]

There's nothing wrong with the oil filter housing. I haven't replaced one ever on these engines. The N52 has an aluminum cylinder head bolt right behind the oil filter housing that likes to break off and then will leak like crazy. Can't recall if the N54 has the same aluminum bolt or not, but you need to check it.

[jclausen]

Yea I though the broken bolt was for the non turbos, but good thing to check. It would be interesting with the car running can you take off the oil cap or is it really hard to remove, meaning high crankcase pressure, could leak oil more. And clean every thing off

[Oldmactech]

Don’t have the car close by but the cylinder bolt you speak of is a bolt that attaches the oil filter housing to the engine not an actual head bolt (head gasket related) right. Have a friend that has a BMW specific shop and he maintains he’s replace lots of housings (not just the gasket) due to leaks.



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[White94RX]

If your friend is replacing housings, then he's wasting a lot of people's money for no reason. It's a cast aluminum part. How can it leak? It's sealed with a rubber gasket that hardens over time and leaks. Plain and simple.

And no, the bolt I'm referring to (which I can't even say for sure it applies to N54), is an actual head bolt, from the cylinder head to the block. It is right behind the oil filter housing, on the head, and not from the housing to the head.

[jclausen]

We have not had to replace the housing the gasket is the problem

[Codes2]

How about give the engine an appropriate bath (manually, not pressure wash), and then just watch for it to leak?
If it's basketballs worth, then you don't need to wait for long. I've used UV, and it's OK, but that's for subtle work IMO. This sounds epic.

I'm not familiar with the bolt in question, however, we can observe that there are many, close together, to ensure a totally even pressure on the gasket.
After changing all but the head gasket, I'd expect a leak if a bolt were broken or improperly torqued.

Mine looked like the rear-main seal, but at highway speeds, oil just drifts back and really drops from that region, regardless of sources.

If it is leaking from the OFH, then someone may have over tightened the bolts so intensely that they cracked the housing. I've seen one person admit to this, but as said, it's the least likely thing.

[Bimmer1231]

So I’m looking at a 06 330i with 160k miles. The guy says the car has been meticulously maintained and has never seen a light on the dash this is what he’s saying, the car is the perfect spec I’m looking for. With 160k miles on it tho, I’ve never owned a bmw but I know a little about them. What are things I should look for and is this even a good buy? Will this car be reliable if I keep maintaining it?

[JDStrickland]

So I’m looking at a 06 330i with 160k miles. The guy says the car has been meticulously maintained and has never seen a light on the dash this is what he’s saying, the car is the perfect spec I’m looking for. With 160k miles on it tho, I’ve never owned a bmw but I know a little about them. What are things I should look for and is this even a good buy? Will this car be reliable if I keep maintaining it?



You are not looking at the E93, you are asking about an E46. The engine in the E9x is an N51 or N52 unless it's the turbo, then it's an N54. The 330 engine is an M54.