My E93 Rough Idle! :(

tarekmid · 05-01-2020, 01:16 PM

After I have changed my valve cover gasket on my E93 N52 everything was working fine. Then 3 or 4 days later I started having very slight rough idling. RPM would drop a bit then jump back up every ~10 seconds.

The codes I got are:

29E0 Mixture Control
2D06 Air-mass system

but the check engine light would come on then go away when the rough idle stops. Later I got a code for cylinder 3 misfire.

I've reset Valvetronic limits after doing the job correctly.
I've checked for oil leaks. There is none.
I don't know how to check for vacuum leaks.
One thing I didn't do correctly is seating in those aluminum Spark Plug Tube Seals. I fixed it now. I pushed them all the way in by tapping with a huge socket. Nothing changed in the idle. I noticed that my spark plugs (installed last year) were gunged up with oil on their tips. What's causing this?

This might be completely unrelated to me changing the valve cover gasket, but what do you guys think are the possible culprits. I'm worried about it getting worse!

Phil325i · 05-02-2020, 05:31 AM

Looking at those plugs I would suspect injector issues. They look wet. Could be unburnt fuel? From your error codes it would also be worth cleaning your MAF.

Efthreeoh · 05-03-2020, 07:37 AM

Pull the electrical connector on the MAF and see how the engine runs on a mapped program. I'd bet there is a leak in the intake plumbing past the MAF sensor.

05-01-2020, 01:16 PM	#1
tarekmid Owner of Pyrrha 0 Rep 1 Posts Drives: BMW 328i Convertible '08 Join Date: May 2020 Location: Birmingham, AL iTrader: (0)	My E93 Rough Idle! :( After I have changed my valve cover gasket on my E93 N52 everything was working fine. Then 3 or 4 days later I started having very slight rough idling. RPM would drop a bit then jump back up every ~10 seconds. The codes I got are: 29E0 Mixture Control 2D06 Air-mass system but the check engine light would come on then go away when the rough idle stops. Later I got a code for cylinder 3 misfire. I've reset Valvetronic limits after doing the job correctly. I've checked for oil leaks. There is none. I don't know how to check for vacuum leaks. One thing I didn't do correctly is seating in those aluminum Spark Plug Tube Seals. I fixed it now. I pushed them all the way in by tapping with a huge socket. Nothing changed in the idle. I noticed that my spark plugs (installed last year) were gunged up with oil on their tips. What's causing this? This might be completely unrelated to me changing the valve cover gasket, but what do you guys think are the possible culprits. I'm worried about it getting worse!
	Appreciate 0 Tweet Quote

05-02-2020, 05:31 AM	#2
Phil325i Brigadier General 615 Rep 3,194 Posts Drives: E92 325i MSport Coupe Join Date: Apr 2012 Location: UK South East iTrader: (1) Garage List 2009 BMW 325i Coupe [6.00]	Looking at those plugs I would suspect injector issues. They look wet. Could be unburnt fuel? From your error codes it would also be worth cleaning your MAF. __________________ E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; 3 x chassis braces; diff brace; N53 V-brace; 034 subframe inserts; BMS clutch stop; BMS CDV; RE g/box mounts; Delrin shift bushes; Saikoumichi OCC; Cyba scoops; BMW Perf Exhaust; HEL s/steel brake hoses; M3 rear spoiler; Recaro Sportster CSs; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof/clear front
	Appreciate 0 Quote

05-03-2020, 07:37 AM	#3
Efthreeoh General 17300 Rep 18,726 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	Pull the electrical connector on the MAF and see how the engine runs on a mapped program. I'd bet there is a leak in the intake plumbing past the MAF sensor. __________________ A manual transmission can be set to "comfort", "sport", and "track" modes simply by the technique and speed at which you shift it; it doesn't need "modes", modes are for manumatics that try to behave like a real 3-pedal manual transmission. If you can money-shift it, it's a manual transmission. "Yeah, but NO ONE puts an automatic trans shift knob on a manual transmission."
	Appreciate 0 Quote