Light Rough Idel- Extensive searching with no help

SquashAZ · 01-31-2016, 06:56 PM

Good evening BMW friends. I have done extensive searches on this forum and others and found no similar posted or threads which provide any relevant information. If after reading this please feel free to point to a thread you might know of which might help.

Here goes:
2008 135i 46K miles with many upgrades and ESS tune.
I have a new HPFP which is still under 100K mile warranty after warranty replacement around 15K miles. I also had 3 injectors replaced under warranty. After recent slow cold starts with White smoke I had all injectors replaced out of warranty with 3 of 6 leaking fuel into cylinder for $1800 with original BMW injectors and also did the spark plugs at the same time with original BMW plugs (I now know I should not have done them together but its too late now). when I picked up the car it had a rough idel which I had never noticed before. the cars starts fine but seem to have a slight miss fire, seems like one cylinders is not getting enough fuel or spark. No CEL, no codes. Car still has good power but at times seems to ever so slightly shudder under WOT and of course rough idle. Warm or cold and not always constant except after cold start there is the slight rough idle. Took it back to the shop and they are blaming the ESS tune. It never did this as I recall prior to new plugs and ejectors replacement.

I am going to flash back to stock and see if this solves the issues but I am very doubtful this is the issue. The only other issues I can come up with are the following:
1. Carbon build up in intake (i do have a oil catch can)
2. Damage coil (possible caused by shop error when replacing plugs)
3. Idle Censor or O2 censor?

DO any of you have any other thoughts or input? all help welcomed.

Thank you for the help in advance.

All best,
Squash AZ

all4bspinnin · 02-01-2016, 09:35 AM

If you are over 30k miles and have not had the carbon cleaning done. I HIGHLY recommend doing that first. (every 30 to 40k this should be done)

While they're at it, have them pull the vanos solenoids and clean them.

If you're over 60k, you may want to look at coils as well for maintenance.

SquashAZ · 02-02-2016, 12:27 AM

Copy that, will get the Carbon cleaning scheduled soon. Still not sure this is the issues as the issues was not there before the plugs and injectors were replaced.

Dynamic1 · 06-18-2016, 07:14 AM

I've had rough idle problems myself, and hadn't had much luck getting the car diagnosed at the dealership initially until they finally scheduled my car some time with their master tech.
Unfortunately, I placed too much faith in BMW's lifetime fluid cycle and only changed my oil at the 15k recommended intervals. Now I'm paying for it. This TSB (don't have the actual BMW document) is what is going on with my car... hope my mistakes can help someone else:

01-31-2016, 06:56 PM	#1
SquashAZ Enlisted Member 5 Rep 40 Posts Drives: Sedona Red 135i Join Date: Jun 2012 Location: Scottsdale iTrader: (0)	Light Rough Idel- Extensive searching with no help Good evening BMW friends. I have done extensive searches on this forum and others and found no similar posted or threads which provide any relevant information. If after reading this please feel free to point to a thread you might know of which might help. Here goes: 2008 135i 46K miles with many upgrades and ESS tune. I have a new HPFP which is still under 100K mile warranty after warranty replacement around 15K miles. I also had 3 injectors replaced under warranty. After recent slow cold starts with White smoke I had all injectors replaced out of warranty with 3 of 6 leaking fuel into cylinder for $1800 with original BMW injectors and also did the spark plugs at the same time with original BMW plugs (I now know I should not have done them together but its too late now). when I picked up the car it had a rough idel which I had never noticed before. the cars starts fine but seem to have a slight miss fire, seems like one cylinders is not getting enough fuel or spark. No CEL, no codes. Car still has good power but at times seems to ever so slightly shudder under WOT and of course rough idle. Warm or cold and not always constant except after cold start there is the slight rough idle. Took it back to the shop and they are blaming the ESS tune. It never did this as I recall prior to new plugs and ejectors replacement. I am going to flash back to stock and see if this solves the issues but I am very doubtful this is the issue. The only other issues I can come up with are the following: 1. Carbon build up in intake (i do have a oil catch can) 2. Damage coil (possible caused by shop error when replacing plugs) 3. Idle Censor or O2 censor? DO any of you have any other thoughts or input? all help welcomed. Thank you for the help in advance. All best, Squash AZ
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02-01-2016, 09:35 AM	#2
all4bspinnin Second Lieutenant 38 Rep 206 Posts Drives: 09 135i LeMans Blue/Terracota Join Date: May 2015 Location: Jax, FL iTrader: (0)	If you are over 30k miles and have not had the carbon cleaning done. I HIGHLY recommend doing that first. (every 30 to 40k this should be done) While they're at it, have them pull the vanos solenoids and clean them. If you're over 60k, you may want to look at coils as well for maintenance.
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02-02-2016, 12:27 AM	#3
SquashAZ Enlisted Member 5 Rep 40 Posts Drives: Sedona Red 135i Join Date: Jun 2012 Location: Scottsdale iTrader: (0)	Copy that, will get the Carbon cleaning scheduled soon. Still not sure this is the issues as the issues was not there before the plugs and injectors were replaced.
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