Massive Oil Leak

[marksae]

When I was on the freeway, my car developed a massive oil leak. Oil is everywhere on the front passenger side of the engine. Oil is all over the bottom side of the headers, frame rail, undertray, steering rack, suspension, and the front right wheel well. Prior to this, my car did not have any real leaks. I recently changed the CPV o-ring, front main seal, and the VANOS sealing plate seals. The leak appears to be coming from the timing chain tensioner area.

I removed the VANOS oil line and it did have a broken mounting tab. But when I examined it, there was no obvious sign of failure. I cleaned all the grime off it. The hardline portion of the line didn't have any obvious cracks or pin holes in it, even around the broken tab area. Thinking the flex portion might have failed, I removed the heat shielding but it was dry underneath. So am I wrong to conclude that my VANOS line did not fail? My car does have 168k miles. I plan on replacing the line anyway, but am worried this might not fix the issue. My car runs fine otherwise.

What else could have failed that would have resulted in a sudden massive oil leak? I checked my timing chain tensioner and it didn't back off. I was only able to put a socket on it, but not a ratchet since I didn't have enough room. What else should I be looking at?

Thanks.

[robgill]

I would check the freeze plug in the front of the head behind the VANOS. I had a similar experience and that plug had fallen out.

[marksae]

Okay, I will check the freeze plug. It does feel like something backed off to result in such a sudden leak.

Thanks.

[Mystic3]

Freeze plug (coolant)/massive oil leak ??

[Mystic3]

Freeze plug, massive oil leak, don't see the connection

[Icecream]

When I was on the freeway, my car developed a massive oil leak. Oil is everywhere on the front passenger side of the engine. Oil is all over the bottom side of the headers, frame rail, undertray, steering rack, suspension, and the front right wheel well. Prior to this, my car did not have any real leaks. I recently changed the CPV o-ring, front main seal, and the VANOS sealing plate seals. The leak appears to be coming from the timing chain tensioner area.

I removed the VANOS oil line and it did have a broken mounting tab. But when I examined it, there was no obvious sign of failure. I cleaned all the grime off it. The hardline portion of the line didn't have any obvious cracks or pin holes in it, even around the broken tab area. Thinking the flex portion might have failed, I removed the heat shielding but it was dry underneath. So am I wrong to conclude that my VANOS line did not fail? My car does have 168k miles. I plan on replacing the line anyway, but am worried this might not fix the issue. My car runs fine otherwise.

What else could have failed that would have resulted in a sudden massive oil leak? I checked my timing chain tensioner and it didn't back off. I was only able to put a socket on it, but not a ratchet since I didn't have enough room. What else should I be looking at?

Thanks.

Same happened to me, I looked all over and everything was fine. When I took the vanos line off it appeared fine except a small wear spot on the braided area. I could see no holes and when I tried blowing through it to see if there was a hole, I couldn't. Sure enough when I replaced it the leak went away. I bet it is the line. Mine leak looked line the exxon valdez so I couldn't believe I was unable to even blow air through it.

[robgill]

Here is a pic

https://flic.kr/p/2hEcMQb

[marksae]

Here is a pic

https://flic.kr/p/2hEcMQb

Wow. Is that freeze plug for coolant or oil? I'll pull my VANOS unit off to check for this and also to make sure there aren't any issues with the sealing plate.

Per the Bimmerworld website, the VANOS line operates around 1500 psi. So I guess any small hole could result in oil getting everywhere.

https://www.bimmerworld.com/Engine/Camshafts/BimmerWorld-S54-Vanos-Line.html?gclid=CjwKCAiAouD_BRBIEiwALhJH6LjC-p9sMHdi40dJkHRZs5xleVb4cKnU6XrsmceVf8ztm4YPvFgmvxoCIykQAvD_BwE

[jbfrancis3]

Per the Bimmerworld website, the VANOS line operates around 1500 psi. So I guess any small hole could result in oil getting everywhere.

Yes exactly. With those pressures the compromised area won't necessarily be visible to the naked eye. Given its on the passenger side, it makes the VANOS line the likely culprit by a long shot.

[sapote]

I bet it's the VANOS accumulator line leaked spaying oil under high pressure. No plugs nor tensioner cap loose can cause a massive leak.

OP, how did you detect the leak -- smell or smoke sign?

[sapote]

Freeze plug, massive oil leak, don't see the connection

These plugs (plug the holes which were required during tooling in factory) are on the head, not the coolant plug on the block.

[marksae]

Thanks robgill for the picture. It was the freeze plug! I just used a mirror with a light and I was able to see that mine is missing.

[marksae]

So looking at the parts diagram, it looks like I just need to replace the cap only (part #3). Do I just hammer it on? Looks like this thing is just a press fit. How do I make sure this doesn't come off again?

https://www.realoem.com/bmw/enUS/showparts?id=BL93-USA-12-2003-E46-BMW-M3&diagId=11_2991

[jbfrancis3]

Well damn. Nice find, all

[robgill]

So looking at the parts diagram, it looks like I just need to replace the cap only (part #3). Do I just hammer it on? Looks like this thing is just a press fit. How do I make sure this doesn't come off again?

https://www.realoem.com/bmw/enUS/sho...diagId=11_2991

Correct, part # 07119901197

Yeah you just tap it in. There wasn't a lot of room to swing the small hammer so I also added some Loctite 620 to try and get it to hold better. Good luck!