[udfxrookie]

So my buddy owns a 300i N52 and is having issues with MASSIVE smoke out his exhaust and it is definitely oil. I looked under the car and where the header meets the exhaust the gasket was dripping oil (bottom of headers, start of exhaust pipes), I tightened the bolt which resolved that problem (LOL) but it was a solid indicator of oil leakage as it was very dark.

Here's the video of what's going on:

All images can be found here: imgur.com/gallery/roK5yUy

Compression test on all cylinders shows 200 across the board with cylinder 1 at maybe 190



Plugs are in HORRIBLE shape:


and VANOS needed replaced:


Codes initially were:

DME/DDE [MSV70] | 29F4: Catalytic-converter conversion
DME/DDE [MSV70] | 29F5: Catalytic-converter conversion 2
DME/DDE [MSV70] | 2A82: VANOS intake
DME/DDE [MSV70] | 2A87: Exhaust VANOS, mechanism
DME/DDE [MSV70] | 29D0: Combustion misfires, cylinder 4
DME/DDE [MSV70] | 29D2: Combustion misfires, cylinder 6
DME/DDE [MSV70] | 29CC: Combustion misfires, several cylinders

***This car has NO CATS and has AA headers to account for first 2 codes
After replacing VANOS and resetting codes, nothing has instantly popped back up.

At first I thought it was a blown head gasket, maybe the rings... then I read about the oil separator for this engine being a big cause on this.... any way to test that? Ideas on what this could be?

[e90yyc]

Nice, detailed post. Doubt it’s the head gasket though. That’s just not common, and this also appears to be oil burning and not coolant. I don’t think valve stem seals are a common failure point on this engine, but maybe?

Before you do any further digging, check the PCV system. Since it’s a separate system with the 330 and isn’t integrated into the valve cover, the good news is you can replace things separately.

Also a couple stray comments—some more constructive than others :

• That steering wheel cover though…
• Did you try cleaning the VANOS solenoids before replacing them? Normally the only drawback to replacing potentially good solenoids is the cost, but in your case I see you’ve fitted HiSport solenoids from Amazon… Mayne you’ll get lucky, but don’t be surprised if you’re replacing them again in a short period of time. I know new genuine solenoids are expensive, so if cost is a problem then try some used ones. Cheaper than Amazon and likely to last much longer.

I think you’re on the right track by starting with PCV system. Maybe one of the 330 guys will chime in with some specific suggestions on things to check. I’d just look over everything.

Good luck!

[Noir]

I have no cats mated to 335 Remus mufflers… I don't think I've ever put out that much smoke when my crankcase ventilator was shot. Was totally drinking oil - but I only recall getting something similar to that exhaust display in the cold months when I was in Virginia…

Maybe an opportune time to run some seafoam through the crankcase / injectors and give it a good flush at the end of cycling those cleaners through. Never seen a gnarlier set of vanos, tbh 👀

[udfxrookie]

Originally Posted by e90yyc

Also a couple stray comments—some more constructive than others :

• That steering wheel cover though…
• Did you try cleaning the VANOS solenoids before replacing them? Normally the only drawback to replacing potentially good solenoids is the cost, but in your case I see you’ve fitted HiSport solenoids from Amazon… Mayne you’ll get lucky, but don’t be surprised if you’re replacing them again in a short period of time. I know new genuine solenoids are expensive, so if cost is a problem then try some used ones. Cheaper than Amazon and likely to last much longer.

TY for the info and I will certainly jump on the PCV, I'm used to the N54. As for the cover, not my car but it works with the wrap that's on it lol. The solenoids are actually good, I used them in my N54 until I started building her and it's a set that actually sits on the shelf waiting for a VANOS problem to use for testing =)

[udfxrookie]

Originally Posted by Noir

I have no cats mated to 335 Remus mufflers… I don't think I've ever put out that much smoke when my crankcase ventilator was shot. Was totally drinking oil - but I only recall getting something similar to that exhaust display in the cold months when I was in Virginia…

Maybe an opportune time to run some seafoam through the crankcase / injectors and give it a good flush at the end of cycling those cleaners through. Never seen a gnarlier set of vanos, tbh 👀

I put the headers on for him about 6 months ago and we've NEVER had smoke like this, so no, I definitely do NOT think it's because of no cats, that was mentioned to cover the first two codes regarding the cats

[Brian86]

Oh yea. Oil separator/PCV system. Particularly if it started doing it suddenly.

The check valve in the bottom of the drain is stuck open, and the separator/valve cover inlet is probably clogged, and the diaphragm is probably torn.

It's sucking oil into the intake manifold like a straw in a milkshake.

Pro tip. Use a fuel line disconnect tool to remove the drain line from the oil pan. Or a sawz-all.

[Noir]

Originally Posted by Brian86

Oh yea. Oil separator/PCV system. Particularly if it started doing it suddenly.

The check valve in the bottom of the drain is stuck open, and the separator/valve cover inlet is probably clogged, and the diaphragm is probably torn.

It's sucking oil into the intake manifold like a straw in a milkshake.

Pro tip. Use a fuel line disconnect tool to remove the drain line from the oil pan. Or a sawz-all.

Sawz-all… Signature checks out :

[Brian86]

My car had the super mega oil separator trifecta failure at about 285k. Drank 2 quarts in about 30 miles. There was actually liquid oil dripping out the exhaust discharge as the engine would just pump it through without burning it during misfires. Something like a quart was puddled inside the intake manifold when I removed it.

I put in Beck Arnley replacement parts, no problems in the last 40k. I'm still a little worried my cat's got fouled. I started having cat efficiency malfunctions in the DME, but they haven't crossed the threshold to light up an OBD fault. It also could just be that the car has a lot of miles on it.

[udfxrookie]

Tomorrow I think I will start taking off the manifold and checking the CCV system, and thoughts on valve stem seals? Someone on another group mentioned it...

[Brian86]

Valve stem seals don't go from 'tight' one day to 'James Bond getaway car' fouling all six plugs the next day.

N52 valve stems probably take 20,000+ hours to get that leaky.

[udfxrookie]

@Brian86 LOL that is the greatest example I've heard ty LOL