MyE28.com DEV

So before vintage I did some work on my 5er, which included building a shroud for my K&N, I think the shroud was a bit too tight. That, and my K&N was always a bit crushed and hadn't been cleaned in a while.

On the way down to the show the car belched oil smoke from the exhaust a few times, but ran well. I daily drove it a few weeks afterwards and the smoke got worse.

It sat for a while and I finally pulled it apart to find the K&N totally collapsed, definitely restricting airflow.

Is it likely that the vacuum in the intake was pulling oil past the seal?

I've since replaced the filter, but the car is still belching smoke, especially at idle, only when the engine is warmed up. Those driving behind me say they can smell oil even at speed. I had hoped that it was just oil pooled up in the exhaust burning off, but i'm not sure anymore.

I pulled the drain hose from the turbo while it's running and it seems to be draining well.

Any other ideas before I pull the turbo and send it off to be checked or worse, start doubting my rings?

Strange. I'm having the same issue right now. Just haven't cared enough to look into it.

My turbo exhibits the same symptoms. Likely oil leaking past the impeller shaft seal. Probably time for a rebuilt center section.

So what is it that does the leaking? In my brief research the center section is basically an oil lubricated / cooled plain bearing with two slinger rings and a circlip like ring.

I have no idea if this is coincidence but I used to run Redline 15w50 and literally the day this happened I pumped some Liquimoly into it because I was out of redline.

From my racing days I have to agree with Kyle. One of the teams I worked for had gone so far as to use V-band clamps (right at the turbo) on the intake and exhaust tubing and hydraulic quick disconnect fitting on the oil pressure lines. Talk about quick turbo changes.

The one journal bearing turbo I ever used lost the turbine side oil seal. Very slight amount of oil burn at idle and cruise and a big-ass cloud when you spool it up.

Every other turbo I've run was a GT series ball bearing unit, and I've had zero failures with those. They cost more initially but at least thats the end of it.

I replaced the filter, changed the oil and drove it.

It's doing better, it still smokes a little. I'm not certain that the problem is solved, i'm going to drive it on a few long drives to see if it's just oil in the exhaust burning off.

It won't stop.

the better less diluted oil is helping but its still worn out

check your crankcase/ valve cover breather hose... if that is collapsed or clogged the car will smoke. make sure it is not seeing positive pressure under boost also.

I'll check this out soon. Does the TCD setup put the crankcase under vacuum like it is stock?

BTW I have been daily driving the car, you're right Kyle, it didn't stop.

Patrick McHugh wrote:I'll check this out soon. Does the TCD setup put the crankcase under vacuum like it is stock?

You have the car, right? Trace the crankcase breather to where it goes.

mooseheadm5 wrote:

Patrick McHugh wrote:I'll check this out soon. Does the TCD setup put the crankcase under vacuum like it is stock?

You have the car, right? Trace the crankcase breather to where it goes.

There is not vacuum.

Where does it go?

Here's a pic, it connects to the recirc valve. I don't really know why it does that.

Looks like it goes back to the metered air side of the AFM. Just like stock.

I have a vacuum hose connected on my breather hose. What's purpose does it serve to not have a vacuum hose?

turbodan wrote:Looks like it goes back to the metered air side of the AFM. Just like stock.

There's no AFM because it's MS, but yes, it goes to the intake side of the turbo.

I like to guess at things.

Probably the kit was made for a draw through air meter.

BOV is much quieter venting into the intake and why run
two hoses to the same place from the same general area.
Looks good to me.

In case anyone is interested…

I did a differential compression test today, the results were surprisingly good for a motor that has been FI for years and has suffered much detonation under my MS regime. A few of the cylinders had a slight amount of what I think is valve seal noise I could hear through the oil cap, but not bad. The lowest cylinder was 78/80 hot.

The smoke is in my opinion caused by one of the following, placed in order of probability.

1. Worn turbo seals pushing oil into the exhaust
2. Worn valve seals
3. Worn oil rings

I am going to upgrade to a ball bearing turbo. If it still smokes i'm going to take the engine apart, redo the internals, redo the head and install an MLS gasket and studs.

Basically win win.

I pulled the turbo, manifold and piping today with the intent of replacing the turbo.

I stared at the engine for a long time and decided that tomorrow i'm going to pull the whole thing, go over the bottom end and install an MLS gasket and studs.

Patrick McHugh wrote:I stared at the engine for a long time

That gets me every time

Patrick McHugh wrote:In case anyone is interested…

I did a differential compression test today, the results were surprisingly good for a motor that has been FI for years and has suffered much detonation under my MS regime. A few of the cylinders had a slight amount of what I think is valve seal noise I could hear through the oil cap, but not bad. The lowest cylinder was 78/80 hot.

The smoke is in my opinion caused by one of the following, placed in order of probability.

1. Worn turbo seals pushing oil into the exhaust
2. Worn valve seals
3. Worn oil rings

I am going to upgrade to a ball bearing turbo. If it still smokes i'm going to take the engine apart, redo the internals, redo the head and install an MLS gasket and studs.

Basically win win.

Leakdown through the crankcase is rings. Leakdown through the valves is going to be evident from the intake or exhaust. Its not likely you'll actually hear valve leakage through the oil filler cap. Might be easier to confirm where its actually going with a smoke source.

turbodan wrote:

Patrick McHugh wrote:In case anyone is interested…

I did a differential compression test today, the results were surprisingly good for a motor that has been FI for years and has suffered much detonation under my MS regime. A few of the cylinders had a slight amount of what I think is valve seal noise I could hear through the oil cap, but not bad. The lowest cylinder was 78/80 hot.

The smoke is in my opinion caused by one of the following, placed in order of probability.

1. Worn turbo seals pushing oil into the exhaust
2. Worn valve seals
3. Worn oil rings

I am going to upgrade to a ball bearing turbo. If it still smokes i'm going to take the engine apart, redo the internals, redo the head and install an MLS gasket and studs.

Basically win win.

Leakdown through the crankcase is rings. Leakdown through the valves is going to be evident from the intake or exhaust. Its not likely you'll actually hear valve leakage through the oil filler cap. Might be easier to confirm where its actually going with a smoke source.

I'll know soon… The engine is on a stand in my shop and is getting torn down tomorrow!

How would I have used the smoke machine to find the leakage? Pressurize the cylinders with smoke somehow?

Ed Zachary.

Well, she's out and in a billion pieces!

The exhaust valves look dry and the cylinder walls still show cross hatching (despite 10 years of FI abuse), I'll know more when I pull the crank and pistons, but I think the oil was leaking from the turbo.

The rotor was super loose, lots of play.

I'm still stoked I pulled it, Todd shipping me some goodies!

Nice!

Done, it rocks. I am not excited about the break in period