[Testosteroneric]

//////Solved!//////
Read post #15


2007 750i 84k
***I posted this in bimmer forums, but I can never get a response. I believe you guys can help me out.******
I've search hundreds of threads and can't seem to find a clear answer.

Car just randomly started to idle rough as I pulled into my driveway. Has horrible acceleration/ coughing.
ONLY GET ONE CODE - Cylinder 2 misfire. Sometimes random cylinder misfire as well if left on long enough.

This only happens when the car warms up. After about 60 sec I hear the actuators on the top of the valve covers click a few times and then the car shuts off cylinder 2. At this point the CEL usually comes up and the car begins to shake.
Note- If I pull the maf the car runs smooth. Just a bit laggy on throttle response.

I swapped coils and still get misfire on cylinder 2.
Probably not related, but Cylinder 1 coil had a bit of oil on it, probably time to get new gaskets.

I can also feel the left actuator ticking much harder than the one on the drivers side.

What do you guys think this could be??? I need this fixed asap its my DD.

- - - Updated - - -

Also after swapping the plugs I noticed they had oil on them. Not on the spark area , but on the thread and higher. Is this normal? Would this cause a misfire?
This was in cylinders 1 and 2.
The injectors also had lots of gunk oil build up on them.
Haven't swapped them yet, gotta fix a mini coolant leak first.

Also to note the pcv ccvs are leaking oil into the intake. Idk, if this is normal for a little bit of oil to be in there, but maybe this has correlation to the underlying problem.

 

[Testosteroneric]

Bump, can anyone chime in?

 

[Javster9]

Take it to any independent BMW shop. I would just replace all ignition coils, and plugs. But don't know what to do about the oil on one ignition coil.

 

[jbhoot]

I would tackle the misfire on cylinder 2 first. If coil and plug is fine, I'd check the injectors.

Oil on the plug threads is not normal- maybe the spark plug tubes are leaking.

 

[Testosteroneric]

I would tackle the misfire on cylinder 2 first. If coil and plug is fine, I'd check the injectors.

Oil on the plug threads is not normal- maybe the spark plug tubes are leaking.

I'm going for the misfire first. I also highly doubt that oil can fall through the top of the plugs and into the cylinder. Seems kinda improbable. The oil leaking onto the top wouldn't have any pressure.

 

[TechFreak]

Not sure if this thread helps : :dunno:

http://www.bimmerfest.com/forums/showthread.php?t=530649

 

[Testosteroneric]

Not sure if this thread helps : :dunno:

http://www.bimmerfest.com/forums/showthread.php?t=530649

Thanks, but I've read it and its all about the misfire on cold start and how the HPFP needs to be replaced. Kinda glad those aren't my symptoms. Those HPFPs are expensive.

 

[Mid7er]

Thanks, but I've read it and its all about the misfire on cold start and how the HPFP needs to be replaced. Kinda glad those aren't my symptoms. Those HPFPs are expensive.

Vano solenoid seals replaced already? Not sure if this would solve yours but it did for my 7 with similar symptoms last year. Rough idle when cold around 40 degrees and below. I didn't pull the plugs tho. Then it started doing that again. The oil filler cap gasket was worn out when i pinpointed the vacuum leaks toward to it. Keep it simple and good luck!

 

[Testosteroneric]

Vano solenoid seals replaced already? Not sure if this would solve yours but it did for my 7 with similar symptoms last year. Rough idle when cold around 40 degrees and below. I didn't pull the plugs tho. Then it started doing that again. The oil filler cap gasket was worn out when i pinpointed the vacuum leaks toward to it. Keep it simple and good luck!

Will be checking the vacuum in a bit, thanks bud

 

[jbhoot]

I'm going for the misfire first. I also highly doubt that oil can fall through the top of the plugs and into the cylinder. Seems kinda improbable. The oil leaking onto the top wouldn't have any pressure.

I'm thinking at the bottom of the tubes. See attached photo. I had this problem.

 

[Testosteroneric]

I'm thinking at the bottom of the tubes. See attached photo. I had this problem. View attachment 572784

What were your symptoms? Was this caused by a leaking valve cover?

 

[jbhoot]

Actually, this was because of the spark plug tubes/pipes. Item 12 on this link http://www.realoem.com/bmw/enUS/showparts?id=HN83-USA-12-2005-E66-BMW-750Li&diagId=11_3257

 

[Testosteroneric]

Actually, this was because of the spark plug tubes/pipes. Item 12 on this link http://www.realoem.com/bmw/enUS/showparts?id=HN83-USA-12-2005-E66-BMW-750Li&diagId=11_3257

Oh I see, did that cause misfire issues?

 

[jbhoot]

Sorry - no misfires. I replaced my engine and used the old spark plug tubes and old valve covers. I had a bit of smoke - which actually turned out to be coolant in the exhaust (different and long story )

 

[Testosteroneric]

******Update******

Found the issue!

I pulled the valve cover and found that the number 2 cylinder retainer spring was out of its socket. It actually cracked off the bottom piece of the spring and if I put it back, it only holds on with a millimeter of spring.

Now the hard part is taking the thing apart without messing with the cam. Is there a way to remove the eccentric cam without removing the intake cam?


In the Pics you can see from the top view looking over cylinder 2.
Also I put a mirror under the chipped spring to give a better view

 

[Mid7er]

Speechless... how hard do you drive your 7?

 

[Testosteroneric]

Speechless... how hard do you drive your 7?

Honestly I try to baby it and only got close to red line once lol. Usually its easy driving.
Weird thing is, is that this happened as I pulled into my driveway. I probably drove 2 miles under 30 through the suburbs before I got to my house.

I'm also stumped...

 

[jbhoot]

Good job finding the problem - did you also find the broken part of the spring?

 

[Testosteroneric]

Good job finding the problem - did you also find the broken part of the spring?

It looks fresh, but I couldn't find it. It's probably sitting down in the pan by now.

 

[permituk]

******Update******

Found the issue!

I pulled the valve cover and found that the number 2 cylinder retainer spring was out of its socket. It actually cracked off the bottom piece of the spring and if I put it back, it only holds on with a millimeter of spring.

Now the hard part is taking the thing apart without messing with the cam. Is there a way to remove the eccentric cam without removing the intake cam?

In the Pics you can see from the top view looking over cylinder 2.

Also I put a mirror under the chipped spring to give a better view

This is a weird one, there are no lateral forces on this spring so no reason it should break. Out of curiosity, have you compared this to the other springs there?

Regardless, you can change the spring without taking the whole thing apart, BUT, it's massively fiddly!

I'd also triple check that your intermediary lever is in the correct position because that could also cause them to sit too low. So make sure to compare the position carefully.

When I changed my valve stem seals I inadvertently got in a situation where I needed to do this. I rigged something up using a 1/4 inch socket to pull the spring back to where it needed to be (roughly) I think I spent way too long time on this and I remember wishing I'd just removed everything to do the job instead of using the AGA kit.

So if you're a patient man, happy rigging something up then you can do this by just changing the spring.

If however, this scares you then you need to take the whole eccentric shaft assembly of and follow the BMW instructions which have you mount the whole thing on a special holder and then you can reassemble as per manual instructions.