tonyb635

I've been experiencing an annoying problem over the past two months and it seems to be getting worse. When I start the car all seems ok until I put it in reverse or drive. Then I hear what sounds like a misfire, stumbling RPM is a little unstable and rough idle. During this time when I drive a way it feels more like a misfiring situation. The problem totally goes away after 1-3 minutes. This situation is there when the car has sat for several hours and is cold. I looked for codes with INPA and found nothing except a few idrive monitor and chatter codes. Nothing engine or fuel related. I have the JB4 and it's been turned off for a few days and no change noticed. Plugs were changed at 50k and car has now 86k. Things I'm thinking about are replacing plugs, maybe coil(s) not sure if there is a way to isolate to one if there is a problem. Fuel injection cleaning. I will also consider but will clearly do if its gets worse the carbon removal from the direct injection. Any thoughts?

audiophool

Also 2008 LCI 535xi. I've experienced misfiring from cold starts but to a much lesser degree. Feels like you run over something like a 2x4 when you're creeping out of the garage.

Sometimes pulling away after a start it feels like the transmission is hunting around for gears too.

Goes away very quickly so I'll just be keeping my eye on it.

Booyaazaa

Hey Tony, is the car starting right up? No long crank times.

535DREAMER

I am having the exact same problem with my 08 535xi again. The 1st time I got a check engine light and it was a misfire in cyl 5 & 6. My dealership changed all spark plugs and 1 coil. That worked for about 2 weeks lol. Now I am feeling the same $hit again, but this time i have had 2 long start cranks so maybe my HPFP is going....who knows

tonyb635

Booyaazaa - Everything seems normal except for the rough idle part when started. It also starts normal as always. The rough idle actually get worse or feels worse when car is placed in drive or reverse and you hold the brake. If you release the brake and slowly depart its the same, if you increase the speed it seems ok and after a couple minutes max, its back no normal. I was thinking something with the cold start system, but it was only a thought.

mikegreen

Does it change if you turn the AC on and off?

If you pump the brake pedal to the floor about 5 times very fast, does that bring the idle up?

tonyb635

The ac on or off or pumping the brakes doesn't change the rough idle. Ill try it again in the morning.

mikegreen

How about pulling a plug wire at a time.. when one is unplugged the idle should drop.. if there is no difference in pulling off a plug wire - cylinder is dead - plug wire bad, coil pack, sparkplug, etc..

TTuned

This week just had injectors replaced on 335i 83k mi. symptom = long crank times on cold starts. CPO is worth GOLD on N54s.

tonyb635

Mike, I have not pulled any wires yet. I did try it with AC on/off and pumping brakes 5 times. Ths didn't change anything. If I let it idle it takes 1.5 - 2 minutes and its perfectly normal. Very Strange!