Cyl 6 Misfire after repeated short run times

[CarbonZHP]

I have not been driving the E46 for about a week. Most days, I have to start the car twice a day to change its position in the driveway to make room for other cars. The car never gets to run for more than 30 seconds. After a few days I was getting rough or inconsistent idle on start. Today, it threw a P0306, 6 cyl misfire. Car seems fine, other than a rough idle every few seconds or so. Do you guys predict a real problem? Or just symptoms from being driven only for very short amounts of time?

[TheFinanceGuy]

I would start by swapping the coils to see if the misfire follows. If it does, then bam-easy fix for a new coil. If it doesn't, then could be a problem. Could also be bad plugs from repeated 30 second runs.

Most likely, not a huge problem (though I'm crossing my fingers!).

[UdubBadger]

What kind of plugs you using? I've noticed some misfires when I changed to NGK plugs about 4-5 months ago

[CarbonZHP]

Plugs are Bosch I believe. About a year old. I'm thinking I just need to get the car completely warm for nice and then try to not start it like I have been. Also this isn't my choice, the short durations. I wouldn't do this behavior by choice

[az3579]

Sounds like a coil to me. Follow Patrick's advice and swap the coils between other cylinders to see if the issue follows. If so, replace coil(s).

[CarbonZHP]

Was my original thought. Will do.

[slater]

What kind of plugs you using? I've noticed some misfires when I changed to NGK plugs about 4-5 months ago

which NGKs, seth? (sorry for threadjacking) i'm about to install some BKR6E's.

peter

[az3579]

which NGKs, seth? (sorry for threadjacking) i'm about to install some BKR6E's.

peter

The correct plugs are NGK BKR6EQUP. You're on the right track. :thumbsup

[UdubBadger]

The correct plugs are NGK BKR6EQUP. You're on the right track. :thumbsup

well it's for my M3 so not sure they are same are they?

[UdubBadger]

a lot of guys with the N54's are having issues with misfires when changing plugs at 65k or so.

[az3579]

well it's for my M3 so not sure they are same are they?

I quoted it for Peter; those are the correct plugs for the ZHP. Not sure about the M3.

[slater]

The correct plugs are NGK BKR6EQUP. You're on the right track. :thumbsup

i prefer copper plugs (copper is a superior conductor), and don't mind changing them every 15k... so i am just putting in the BKR6E's. :)

peter

[CarbonZHP]

What I found. Oil around the outside of class 5 and 6. Clean coils. Clean on the inside. Can't really see where the leak is.. It's quite small

http://tapatalk.imageshack.com/v2/14/10/08/fcaa9bad823cf4be3a9f9ca8320e3498.jpghttp://tapatalk.imageshack.com/v2/14/10/08/ec93313a0c31662300f4a963f5b48178.jpghttp://tapatalk.imageshack.com/v2/14/10/08/cc0b0f03711951903196c5395520ec6c.jpghttp://tapatalk.imageshack.com/v2/14/10/08/a6110b9c3e5b6a0d0f7bf5e0ffcd2acb.jpg

[Johnmadd]

That's not the problem.

[CarbonZHP]

Swapped 5 and 6 coils so I'll see. Is this leak a cracked vc?

[Oli77]

How is that oil getting there, either a vcg crack or from filling with oil ?

[CarbonZHP]

Don't believe it's from filling so I have to go with crack or gasket. This leak is brand new to me

[danewilson77]

Don't believe it's from filling so I have to go with crack or gasket. This leak is brand new to me
+1

No flame suit required!

[CarbonZHP]

Still does not solve my original problem, only adds a new one (I think?). Right now Im unable to pull the spark plug to check it, dont have an extension long enough.

[Johnmadd]

Still does not solve my original problem, only adds a new one (I think?). Right now Im unable to pull the spark plug to check it, dont have an extension long enough.

Tool kit in the trunk is missing the tool?

[CarbonZHP]

You mean the tool to remove the wheels?

[Johnmadd]

You mean the tool to remove the wheels?
Yep, wait no

[CarbonZHP]

Yeah doesnt work

[Johnmadd]

This http://i1210.photobucket.com/albums/cc407/johnmadd1979/20141008_191205.jpg (http://s1210.photobucket.com/user/johnmadd1979/media/20141008_191205.jpg.html)

[CarbonZHP]

Never seen that before in my life.

[Johnmadd]

And you use the wheel tool to spin it... it's awesome lol

[CarbonZHP]

Haha sounds random. No I dont have that so hopefully Ill have the plug out tomorrow. Hopefully will drive it tonight to test

[danewilson77]

You mean the tool to remove the wheels?
No...to remove the spark plugs.

What's going on up in heya?

No flame suit required!

[CarbonZHP]

Just didnt know a special tool to remove the plugs was ever in that tool box. So all I could of think of was the wheel tool. So no I dont have that tool.

Heya?

[danewilson77]

Ok. Yeah...it goes in the top spot. I use it every time I do plugs, so I know what you're going through not having one.

No flame suit required!

[CarbonZHP]

For sure. Opinions on the look of my leak?

[UdubBadger]

I quoted it for Peter; those are the correct plugs for the ZHP. Not sure about the M3.

Ah gotcha

[az3579]

And you use the wheel tool to spin it... it's awesome lol

I only use the wheel tool to stick in the lug holes when removing wheels so it's easier to reinstall. :dunno
Only works with two though, and I lost BOTH of them. :facepalm

[TheFinanceGuy]

Yikes- That leak looks like a cracked VC to me. You would need to pull it to be certain. This leads me to ask how a VC cracks. I've heard of this happening, however never actually seen it.

Is there a Harbor Freight tools near you? Extensions are cheap there. Not the highest quality, but it works. A spark plug socket with the rubber cup on the inside is nice too. Saves you need to fish the plug out of the well.

You also said you have another problem now? What is the second issue, aside from a cracked/leaking VC? Did you clear the misfire code before moving the coil?

[CarbonZHP]

The main issue and the reason I took this apart was the misfire. I cleared it before this but haven't been able to drive it yet to see if it's still there

[CarbonZHP]

A leaking VCG I can believe. They said it might leak after I did the catch can.

[danewilson77]

Not the gasket. The actual cover....

[CarbonZHP]

Not the gasket. The actual cover....
Better not be...

[danewilson77]

Or what? You're gonna kick it's ass? Lol.

I just don't see how oil gets there with a leaky gasket.

I guess we'll both cross our fingers.

No flame suit required!

[Sockethead]

If i remember right, Aren't there gaskets around each spark plug hole?
Clean everything up, check plug.
You can use a bunch of shorter extensions and spark plug socket tape them so they don't come apart in the hole...
I just want through this on my car. Haven't run for two months.. Sat in the garage with less that 1/4 tank.
Ran like shit for a couple of days.... Misfire on every cylinder. It smoothed out after I ran 1/2 tank of fuel through it. I cleared the codes and added BMW injector cleaner and a full tank of fuel. Seems to be ok now...

[CarbonZHP]

Yes theres gaskets along the center, around the spark plug holes. Im just not sure if that would cause it to leak out, or into the coil area. The coil was all clean. Oil is only on the cover

[LivesNearCostco]

I *think* oil on the cover (if it doesn't come from oil spilled during top ups--I've done that many times) can come from the bolt gaskets. There are 11-15 small bolts or studs holding the valve cover on and 2 or 3 (or 4) of them are in the middle around the spark plug holes. Each one gets a small round rubber gasket. So around perimeter one big rectangular gasket. Two "six pack" gaskets in center (each with 3 holes) around spark plug wells, then 11 or 14 or 15 of the little rubber round ones.

Edit: Forgot to add
--Leaking VCG gasket leaks on right/passenger side onto exhaust manifolds (lowest point) or in back by half-moon cutouts
--Leaking "six pack" gaskets (3 holes each) usually leak into spark plug wells
--Leaking grommets would leak around bolt heads onto valve cover itself

[Dave1027]

Carbon, you have the catch can so vacuum is higher. Could the increased vacuum have cracked the VC? If it did, how does oil then spray out? It should be sucking air which I could see causing a misfire.

[slater]

I *think* oil on the cover (if it doesn't come from oil spilled during top ups--I've done that many times) can come from the bolt gaskets. There are 11-15 small bolts or studs holding the valve cover on and 2 or 3 (or 4) of them are in the middle around the spark plug holes. Each one gets a small round rubber gasket. So around perimeter one big rectangular gasket. Two "six pack" gaskets in center (each with 3 holes) around spark plug wells, then 11 or 14 or 15 of the little rubber round ones.

this is a very good possibility for the leak...



Carbon, you have the catch can so vacuum is higher. Could the increased vacuum have cracked the VC? If it did, how does oil then spray out? It should be sucking air which I could see causing a misfire.

i certainly hope this isn't the case, but i am curious! OP, let us know when you can get the VC off for inspection.

peter

[CarbonZHP]

After a very quick check this morning, one of the center bolts with the rubber gasket seemed to be dirty. Still need to clean thoroughly and drive.

[Sockethead]

Yea if those gaskets fail they will fill the spark plug holes

[LivesNearCostco]

If VCG is very old, it can break upon removal, so if you're planning to inspect it for failures, I recommend having a new one on hand along with all those little rubber grommets.

[Sockethead]

My valve cover gasket was shot when the car was only 4 years old

[Dave1027]

Hey Carbon,

Any update on this issue? How did the VC turn out? Was it in fact cracked? If so how did it happen?

[CarbonZHP]

Meant to update. Got a chance to drive a good distance last week. Car ran great. No misfires. Everything nice. Haven't pulled the VC, but I cleaned where the oil was collecting so I can go back later and find the source