[duckiebmv123]

Hi all,

Just came back from my local mechanic and been informed my PCV pipe on my n52 is blocked. Took it in due to oil leaking down from front of engine onto the belt making it chirp (didnt want belt to snap and get eaten by the engine.) He is going to replace the pipe along with the rocker cover as the backpressure from the block is making oil seep through most seals. He said there is a chance this may of caused the main seals to get damaged which sadly would of cost more than I can afford and what the car is worth. Has anyone had a similar issue and know the symptoms of the main seals leaking (front and rear crankshaft). It does not leak onto my driveway and i don't have any smoke when driving.

[sonofsun]

Not sure if it would cause oil leak at the front onto the belt. The way the valve cover is angled, the possible leak point would be on the right side of the valve cover just near the firewall. Positive crank case pressure is a bad thing though. It can possibly cause the main seals to leak but not sure how long you ran like that though.

By rocker cover I am thinking you are talking about the valve cover. Yes most of these have a built in oil separator inside the valve cover. I think the N-52 also has a standalone oil separator tucked between the manifold and the engine. Others can confirm.

[sonofsun]

Depending on the miles, have your DISA valves inspected for damage. Mine was damaged. I am replacing it as we speak.

[duckiebmv123]

I am not sure how long I have been running it for like this, I only noticed it when the belt started to squeak about 2 weeks ago and saw the oil on it. there is no oil leaking directly from rear seal onto my drive so hopefully they are still holding up, even if it seeps a little.

[ptpending]

this is absolutely standard problem for every N52, but person who feel burnt oil taste earlier and do oil filter gasket and PCV replacement are more lucky
the valve cover integrated with PCV replacement job is not very complex if you have garage and tools

[e91Owner]

Given that you're not in the US, does your 330i have a magnesium or plastic valve cover? The 330i was only sold briefly in the states and the advice you might get from the predominately US posters here may not relate to what you have (e.g. later EUR 330i have no DISA).

Along those lines, it's always good to post the MY and model in your posts.

[ptpending]

my N52 car is 2007 man date and it has plastic cover with integrated PCV and i own it for 5 years
but before this car i owned e46 car with M47 from 2009 and E91 with M47N diesel from 2011 which also has oil leak issues until its PCV function will not be remediated
the only implementation of PCV function is different
the whole concept bmw have if PCV not working, you will have oil leaks

[duckiebmv123]

My bad it’s a 2007 330i with 170k on the clock. most of the usual suspects have been replaced by a friend who owned it previous to me. I am not sure on the material of the cover as i haven’t seen it myself but i can do a quick google search. I do have a garage currently working on the car giving it a new pcv pipe. Cars got a lot of miles on it, i was unaware of this being an issue as im pretty new to BMW and working on cars in general, but i imagine this is a common issue especially with the higher mileage motors. Just hope all else is okay it hasn’t been ran like this for too long as if the crankshaft seals have issues then im not sure what the next move would be.

[duckiebmv123]

Update for thread:

Mechanic called me, cleaned breather and the crank seals are okay. New vanos seals needed. Caught it in good time luckily. Thanks for the help everyone.

[ptpending]

you better also do the oil filter housing gasket replacement as well
or wash all around oil filter housing and inspect for the leaks