Oil Leak

[dreamingat30fps]

Ok so I am back to daily driving the Z and I'm trying to fix an issue once and for all. She has been leaking oil (not a lot) for a while now. First I was told it was the cam sensor (I believe) and so that was replaced. Still leaked, I was pretty sure it was coming from the actual valve cover seal, they agreed and replaced that (which had been replaced not that long ago when they did valve adjustment) anyways here we are today she's still leaking.

Again its not much just a couple drops on the floor but it's pissing me off as I always try to keep her in mint condition and this is one issue that doesnt seem to go away.

Any of you guys experience this? Any common leak areas in this engine I should be focusing on?

[itdnwiwbp]

Any idea more specifically where it's coming from? Could it be the CPV o-ring at the back of the block on the passenger side? If it's drops probably not unless it's really leaking but maybe worth a look.

[dreamingat30fps]

This is what I can see from the top. Keep in mind this was all cleaned a couple months ago so that oil is new from within a few months.

[itdnwiwbp]

Definitely not the CPV up there. All the way back by the O2 wires on the heat shield makes me think valve cover but since that's been replaced could possibly be a leak at the CCV line seal in the center of the valve cover or your oil cap not sealing causing a leak that's difficult to see with out the black plastic cover removed? Is there any oil at the front of the block or only down the side and rear? I would think either of those two things would be noticed during the valve cover replacement so hopefully there isn't something warped.

[dreamingat30fps]

Originally Posted by itdnwiwbp

Definitely not the CPV up there. All the way back by the O2 wires on the heat shield makes me think valve cover but since that's been replaced could possibly be a leak at the CCV line seal in the center of the valve cover or your oil cap not sealing causing a leak that's difficult to see with out the black plastic cover removed? Is there any oil at the front of the block or only down the side and rear? I would think either of those two things would be noticed during the valve cover replacement so hopefully there isn't something warped.

Nothing at the front at all. The further back you go the more oil. It actually goes down the lines on the last pic and they are covered in oil once you get further down. The sensor on the 2nd pic is the one that was replaced originally.

[itdnwiwbp]

Can you take a few minutes to pop the black plastic cover off to see if it's coming from either the CCV seal or oil cap? Remove the CCV hose (pinch connection), oil cap and 6 10mm chrome nuts.

[dreamingat30fps]

Looks pretty clean in there to me. Of course with my luck I lost one of the chrome lugs and now I cant find the sob for the life of me.

[XMetal]

Are you using an OE BMW valve cover gasket? I'm getting a similar minor leak as well with an aftermarket valve cover gasket on my previous valve adjustment. I'm going with an OE BMW gasket on my next go round.

[StickMon]

My money would still be on CPV O-ring.
The leaking oil blows all over hell from turbulence when you're cruising.
When mine blew it was all up on the head along the right side.

[elerner61]

How about changing the CPV O ring and seeing if that stops it? It's eventually going to leak if it is not this current leak. It's cheap to do and only a minor pain in the ass.

[itdnwiwbp]

I didn't have oil anywhere but below my CPV when I replaced it recently but maybe my leak was just very minor. Regardless, even with the pain in the ass of doing it with the headers on I'd still try that before replacing the VCG again since it likely needs it anyway. Use this o-ring: http://www.rogueengineering.com/rogu.../S54CPVOR.html

[dreamingat30fps]

Yeah I'm gonna check that out, didn't even know about the CPV till now thanks

[Clearancediver]

Oil filter canister...... O-ring That forms the deal with the screw top cover. Wrong torque and o-ring bulges slightly and then starts to leak. It's likely bulging on the back of the cover where you can't see. I solved my problem with that issue by getting a stainless steel clamp the right size to fit around the canister /o-ring and tighten lightly. Just enough to snug up to the canister and o-ring. While the "purists" might twitch their eyes brows at this... It's costs about $4 to do..and solves/eliminates any possibility of an oil leak from this area.

The canister/o-ring seal is a lousy design as there is no "depression in the canister top for the o-ring to settle in so if the torque isn't just right the o-ring is squeezed out... Especially when it heats up.