[themyst]

Got around to doing plugs today, and it appears cylinder 6's plug threads were covered in oil and plug tip covered in carbon (maybe oil residue)?

Doing some digging on e90, it appears the valve cover gasket may be the issue. Anyone here experience this and did the valve cover gasket resolve the issue? I found nothing overly conclusive.

edit - the coil pack was dry when pulled.

[E90Company]

That's very interesting.

[onebadmofo]

What is that in the background?

[The Ghost]

I would do a compression check. Was there oil on the other end of the plus (where the coil pack goes)? If not, I doubt it's the gasket. In fact, a leak at the gasket wouldn't make it past the threads to the electrode end. If it's oil, IMO you have a ring issue (or valve stem seal). It's it's carbon, perhaps an add fueling issue. I'd do a compression test to eliminate a ringland/ring issue.

[OpenFlash]

Originally Posted by The Ghost

I would do a compression check. Was there oil on the other end of the plus (where the coil pack goes)? If not, I doubt it's the gasket. In fact, a leak at the gasket wouldn't make it past the threads to the electrode end. If it's oil, IMO you have a ring issue (or valve stem seal). It's it's carbon, perhaps an add fueling issue. I'd do a compression test to eliminate a ringland/ring issue.

+1
A leaky valve cover gasket wouldn't wet that tend of the plug unless it got wet during installation. You should be able to shine a light down in the spark plug hole and see if there is oil on the walls. If so, the valve cover is definitely leaking. If not, it's coming from the combustion side.

[themyst]

Originally Posted by The Ghost

I would do a compression check. Was there oil on the other end of the plus (where the coil pack goes)? If not, I doubt it's the gasket. In fact, a leak at the gasket wouldn't make it past the threads to the electrode end. If it's oil, IMO you have a ring issue (or valve stem seal). It's it's carbon, perhaps an add fueling issue. I'd do a compression test to eliminate a ringland/ring issue.

I did do that actually lol. I just didn't feel like retyping that info from another site that I originally posted on. Compression was consistent across all cylinders. I would guess leakdown test is next?

The coil pack was dry, only the threads were soaked in oil, as you can see in the picture. The electrode itself appears to be covered in carbon. I just can't buy the fact I could potentially have two issues in the same cylinder? I truly believe that the deposits on the electrode are burned oil and not fuel. If it were fuel I would definitely look into replacing the cylinder 6 injector.

The car does not have the symptoms of a failing injector (car does not misfire, car does not rough idle on a cold start, car runs fine from what I can tell).

I will check the spark plug hole for cylinder 6 with a flashlight and see if the threads are covered in oil.

Then again, if the valve seal gasket and leakdown tests do not fix the problem, it may be time to buy into the fact something's broken in there. I don't really think so though since the car runs fine.

[MilehighM3]

Do you think it's possible that there is a crankcase ventilation issue on cylinder 6? Perhaps the low pressure side of the ventilation system has a leaking check valve (in the valve cover) that is leaking under boost?
If your cylinder leakage test turns out okay, maybe it's worth looking into. I'm sure you know to do the cylinder leakage test with the engine hot, so I hope your results come out in the acceptable range.
Do you have or have access to a bore scope to get a good look at the cylinder walls?
Perhaps you have a valve seal issue causing the oil build up also?
Am I correct in the fact that you have RBs? Did you notice any oil build up on the exhaust valves or the #6 exhaust port when you installed them if so?
You may pop the intake off and try to determine if the valve seals are leaking, which may be tough with the typical carbon buildup.
That's a lot of ideas, but you may run out of other ideas on your own. Definitely keep us in the loop!

[The Ghost]

Originally Posted by themyst

I did do that actually lol. I just didn't feel like retyping that info from another site that I originally posted on. Compression was consistent across all cylinders. I would guess leakdown test is next?

The coil pack was dry, only the threads were soaked in oil, as you can see in the picture. The electrode itself appears to be covered in carbon. I just can't buy the fact I could potentially have two issues in the same cylinder? I truly believe that the deposits on the electrode are burned oil and not fuel. If it were fuel I would definitely look into replacing the cylinder 6 injector.

The car does not have the symptoms of a failing injector (car does not misfire, car does not rough idle on a cold start, car runs fine from what I can tell).

I will check the spark plug hole for cylinder 6 with a flashlight and see if the threads are covered in oil.

Then again, if the valve seal gasket and leakdown tests do not fix the problem, it may be time to buy into the fact something's broken in there. I don't really think so though since the car runs fine.

If your compression test showed high and consistent numbers (what were your numbers across all 6?), then a leak-down won't tell you much outside of where the air is escaping (and if your numbers are strong, it should be past the rings at a low rate). Even if oil was leaking past the valve guides, a leak-down test wouldn't tell you because the valves are closed.

[themyst]

Originally Posted by Bmw135er

Do you think it's possible that there is a crankcase ventilation issue on cylinder 6? Perhaps the low pressure side of the ventilation system has a leaking check valve (in the valve cover) that is leaking under boost?
If your cylinder leakage test turns out okay, maybe it's worth looking into. I'm sure you know to do the cylinder leakage test with the engine hot, so I hope your results come out in the acceptable range.
Do you have or have access to a bore scope to get a good look at the cylinder walls?
Perhaps you have a valve seal issue causing the oil build up also?
Am I correct in the fact that you have RBs? Did you notice any oil build up on the exhaust valves or the #6 exhaust port when you installed them if so?
You may pop the intake off and try to determine if the valve seals are leaking, which may be tough with the typical carbon buildup.
That's a lot of ideas, but you may run out of other ideas on your own. Definitely keep us in the loop!

Yes, I have RBs but they were only installed for like 200 miles. Whatever issue I have likely happened before they were put in. Definitely will update this thread with results.

[The Ghost]

And I've blown many a motor, and even when I had 60psi in a cylinder, the plugs were not soaking wet nor had burnt oil (the ringlands were cracked, but nothing catastrophic). I'd think burning that much oil would show through your exhaust and, if it was coming past your rings, on the compression test.

How many cranks did you do and which order did you do the test (1-6, or 6-1)? I normally do it twice to make sure it isn't a temperature / fuel washed-induced inconsistency.

[themyst]

Originally Posted by The Ghost

And I've blown many a motor, and even when I had 60psi in a cylinder, the plugs were not soaking wet nor had burnt oil (the ringlands were cracked, but nothing catastrophic). I'd think burning that much oil would show through your exhaust and, if it was coming past your rings, on the compression test.

How many cranks did you do and which order did you do the test (1-6, or 6-1)? I normally do it twice to make sure it isn't a temperature / fuel washed-induced inconsistency.

3 maybe 4 cranks? I have a feeling it was done incorrectly as the throttle needs to be completely open to get an accurate reading. All six cylinders showed 90-120 psi depending on the number of cranks, which based on feedback received elsewhere is incorrect. Either incorrect, or a really fubar'ed motor.

Apparently the correct way to do a compression test is to crank the motor until it stalls out?

Car starts right up, doesn't misfire, no codes, idles smoothly, no issues as far as I can tell. Car makes plenty of power (stock turbos or RBs), good enough for 118 mph in the quarter mile on stock turbos, full weight, stock wheels/all-season tires. I do have an ignition timing flatlining issue, and I am going to check the injector coding as well tomorrow to see if that can be related. I doubt it since the car does not flat line timing on the stock tune.

[dfv2]

Originally Posted by themyst

Apparently the correct way to do a compression test is to crank the motor until it stalls out?

No no, that is to run the fuel line dry prior to conducting the test, so that no fuel remains in the cylinders, and no fuel is injected during the cranking procedure.

I'm not sure how you might hold the throttle blade open? Were you cranking by jumping the starter leads or by using the start button? Once you figure it all out let us know!

[onebadmofo]

Remove charge pipe and stick the throttle blade open with a finger?

[OpenFlash]

You don't need to hold the throttle blade open. Just unplug the connectors going to each of the fuel injectors. Remove all 6 plugs. And then test each cylinder with 10 cranks. Pressure will stabilize after the 6th or 7th crank. It's also useful to know what pressure is on the 1st crank but that requires two people.

shiv

[MilehighM3]

Originally Posted by themyst

Yes, I have RBs but they were only installed for like 200 miles. Whatever issue I have likely happened before they were put in. Definitely will update this thread with results.

You don't have the infamous RB oil burning issue do you?

[Jeff@TopGearSolutions]

Compression test are not done to crank motor over. You dont want the motor to crank over that is why you disconnect injectors and coils.

You just want to turn over the motor until you get your highest reading on the gauge.

However many cranks it takes is usually what people go for but it should be around 5-10.

Usually something around 180 PSI. The build up past the threads is interesting, initially I thought it may be a bad injector though until i realized the black went further up. Not so sure now.

Usually if the coilpack is oily its the valve cover gasket.

[themyst]

Originally Posted by Bmw135er

You don't have the infamous RB oil burning issue do you?

Wouldn't know, I had them installed for 200 miles. But haven't lost any oil yet.

No blue smoke out my tailpipes or anything either.

I am wondering if running that BSH OCC for a while may have contributed to this issue? Cylinder 6 is quite close to the pcv tubing. No OCC as of around 4000 miles ago.

[marv85]

Originally Posted by themyst

Wouldn't know, I had them installed for 200 miles. But haven't lost any oil yet.

No blue smoke out my tailpipes or anything either.

I am wondering if running that BSH OCC for a while may have contributed to this issue? Cylinder 6 is quite close to the pcv tubing. No OCC as of around 4000 miles ago.

Wasn't it determined that the BSH OCC was restrictive and could lead to such issues? or am I mistaking it for another OCC.
but this is a good point either way and I think it's worth buying the BMS OCC as a precaution.

[themyst]

Originally Posted by marv85

Wasn't it determined that the BSH OCC was restrictive and could lead to such issues? or am I mistaking it for another OCC.
but this is a good point either way and I think it's worth buying the BMS OCC as a precaution.

would the BSH OCC toast a valve seal or valve cover gasket? Don't know, but when I ran the car hard with that can, I would lose a half quart of oil after 5-6 hard pulls. Once the can was removed, no issues whatsoever. Didn't lose a drop of oil, no smoke, no nothing. Did 5 60-130 pulls with no cooldown and no oil loss. Just white smoke on cold start but that appears to be normal for a catless car.


Perhaps the oil collected on the plug was just residual from back when I had the BSH OCC installed, and the oil collected immediately on the new plug just remnants from that? It's been 4000 miles since I removed the can. I will do a proper compression test, clean the spark plug hole, try an old clean plug and see if it fouls right back up.


Is there any definitive evidence that the coil pack sleeve would be covered in oil on this platform? I have dug through this site extensively and found nothing that visually confirms that the coil pack would get oil on it on a bad valve cover gasket.

[themyst]

Just stretched out the car this morning. Runs great, engine responds smoother than ever. Very confusing!

[geterdone]

Just went to change the plugs out and my #6 plug looked the same. Car runs great and does not consume oil???

[R1000K3]

Originally Posted by themyst

Got around to doing plugs today, and it appears cylinder 6's plug threads were covered in oil and plug tip covered in carbon (maybe oil residue)?

Doing some digging on e90, it appears the valve cover gasket may be the issue. Anyone here experience this and did the valve cover gasket resolve the issue? I found nothing overly conclusive.

edit - the coil pack was dry when pulled.

Move the coil and see if if the problem follows. If it remains on 6th I think it is the injector. This will also foul the plug since the combustion is not what it should then.