Help/Advice-misfire (long-ish)

[Washburn]

OK. I will start to keep this as concise as possible.
Although I have posted a bit about this in another thread, I didn't address the main story, nor was I very detailed.

PART 1:

2005 ZHP - 47k miles. No Mods except Dinan intake and SprintBooster. Sits a lot.

ISSUE:
After a long period of sitting (we have been on vacay), on cold day car started and idled rough. Visible, palpable shaking.
Turned car off, started again: SES on, Started rough but settled into a smoother idle. RPMs steady and normal. But feels like its not the normal "sound/beat/pitch" of idling. No more shaking though.

Driving: Almost normal; slight feel of reduced power. SES still on. Idling still smooth.
Now when starting the car: Starts like normal "pitch", but after 2-3 seconds, drops to a lower pitch, but smooth. (but RPMs still normal).

Code checked at Adv Auto: P0302 : Cyl 2 misfire.

First suspicion: bad coil pack.

So, this is what I did:

-Got a basic code scanner; Scanned car again at home. (SES still on). Got same code as before : P0302
-Starting the car: still same symptoms; Starts like normal "pitch", but after 2-3 seconds, drops to a lower pitch (but RPMs still normal).
-ERASED the code, using the scanner.
-Swapped coil packs 2 and 3 (so now, suspected bad coil is on cyl 3), expecting / hoping a new SES will result with a Cyl 3 misfire code.
(Both coil packs looked similar in appearance to my newbie eyes; Spark plug wells also looked clean)

Started car again: Idled rough and shaky (just like when the SES came on before) for only a few seconds, but then settled to a smoother idle, and remained smooth. RPMs steady.
But.... NO new SES!
(in almost all troublshooting threads I have read, people got the "new" SES shortly after swapping CPs)

Since then, Car started like normal but "drops" the pitch / sound of idle. (The idle "changing" after immediate start feels like same change of sound that I listened to in a lot of YouTube videos: when a coil pack is unplugged.)
Driving: Same as before coil swap: Almost normal but not quite normal power.

This behavior remained for several days, and still no new SES. Have driven about 30-40 miles since then in different driving conditions.

Latest: Now the car starts like normal, and does NOT change the pitch / sound of idle. In other words, starts and idles like before any of this ever happened. BUT while driving I STILL feel like the car is not running on full power....
(still no SES and no stored codes)

So, I am baffled. I don't know why I never got a new SES after the CP swap. I think I have driven the car enough for it to come back.
Question: If I have to keep driving to get it back, then how bad is it to drive it in this condition? IDK if it's running on 5 cyl or what..

PART 2:
(sort of unrelated to Part 1)
While I was practicing pulling off coil packs (I found it hard), I pulled CP on Cyl 1 (remember this is NOT the cyl that misfired): -the boot remained on the plug and there was some wetness on the CP. Several people suggested that at least on THAT cylinder, there might be some leaking of the spark plug well gasket/seal.

Although this not related to cyl 2 misfire, I want some opinion of the following:
My local indie BMW shop is running a special on VANOS rebuild ( with anti rattle kit ) and VCG replacement - they're pretty good at what they do, and their special is not bad - they do this special annually, and use Beisan kit.

This would be the prefect opportunity for me to get the VCG and the spark plug well gaskets replaced and cleaned I think.
As far as VANOS, my car is by most standards too young at 47k miles
But I have heard people post or say that Vanos rebuild is beneficial even at a young mileage and sometimes I have heard a rattle noise but I have no idea is it's Vanos or not ...

What do you guys think ? Should I go ahead and get it done ?
And although it might be too early should I replace the plugs and / or the coil packs ? It would be easy for them to do as they have remove all that anyway to do the Vanos / VCG

Summary:
Thanks for reading so far. What should be my next step?
-should I just wait and wait and drive the car while waiting for the SES to reappear?
-But is it bad to drive with this "reduced power"-feeling? Is it running on 5 cylinders? (Hope not)
-Should I get the whole thing (VCG/VANOS, CPs, SPs) done?

[danewilson77]

No P0174? P0171?

"No flamesuit required"

[Washburn]

Nope. Nothing except the initial P0302, which I erased/cleared with the scanner before swapping coils.

[danewilson77]

And you can feel it still missing?

"No flamesuit required"

[Washburn]

Well, it IDLES like normal (as in like BEFORE the rough idle/misfire/CEL episode, its usual self.).
While driving, though, car feels a but underpowered/slow or something.
I can't say for sure if I "feel it missing" - I am not sure what to look for while driving (or idling) to determine if it's missing or not.

Any pointers on what symptoms I should look for ?

[danewilson77]

Well, you would know if your missing or running on 5 cylinders. Engine would "stumble".

"No flamesuit required"

[Washburn]

Nope - no stumbling at all while driving or idling. Just feels like it has lost some "oomph" and powah, but smooth.

[danewilson77]

Nope - no stumbling at all while driving or idling. Just feels like it has lost some "oomph" and powah, but smooth.
Mmmm...interesting.

"No flamesuit required"

[danewilson77]

I'm thinking your next step should be swapping injectors.

"No flamesuit required"

[danewilson77]

More info here:

Causes
Possible causes of OBD code P0302
A code P0302 may mean that one or more of the following has happened: Faulty spark plug or wire Faulty coil (pack) Faulty oxygen sensor(s) Faulty fuel injector Burned exhaust valve Faulty catalytic converter(s) Running out of fuel Poor compression Defective computer

Possible Solutions
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back. If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

"No flamesuit required"

[Washburn]

Thanks - as there is no stumbling etc I think I am going to wait for SES and get the Vanos / VCG thing done anyway in the meantime - if the SES comes back on before that, I can rule out or determine it is a CP, depending on the code. If the SES doesn't come back by the time car is at indie place for VCG etc, I will have them check the car out with their diagnostic software.
I will have new spark plugs and CPs ready just in case when I take the car to them.


Sent from my NOT bent iPhone 6 using Tapatalk

[Jon D]

How long sitting, if 2-3 months could just be the gas separating, add some treatment to the tank.


Sent from my iPad using Tapatalk HD

[Washburn]

It was about two and a half weeks.