[Streetluger06]

My car has been misfiring lately at idle and I am looking for suggestions on how to alleviate it. I recently put downpipes on and changed my turbos for better condition stockers. I don't recall having this issue before I tore into my car. When I run it through the rpms it doesn't seem to have any issues.

I replaced my plugs less than 2,000 miles ago with new factory ones. I just finished running 2 treatments of techtron through my injectors. Two weeks ago I had my HPFP replaced under the recall and that cleared up a 6th cylinder misfire I had.

When idling I hear a poping/pinging sound coming from the downpipe/turbo area that seems to happen randomly. There are roughly 10 misfires a minute. I do not have any check engine lights coming on but it still is bugging me that its not running properly. My car is a 2007 335i and has 67,000 miles on it and to my knowledge has never had the valves cleaned or the injectors replaced. I am running amsoil synthetic with less than 2,000 miles on it.

Could my misfire be caused by carbon build up on my intake valves?

Is this normal and I am just not used to it since these downpipes are new to me and the stock cats would typically absorb the sound?

[Mike@N54Tuning.com]

Spark plugs, Injectors, Coils, HPFP?

Mike

[s2k_335i]

Do you have procede? If so try a different map. Also try to change your spark plug. I had misfire last year and the spark plugs took care of the issue.

[gsmurf]

Check your spark plugs again.

[jdbretz]

Are your misfires all on the same cylinder? Is it storing a misfire code, or are you just saying it sounds/feels like a misfire?

[Streetluger06]

Originally Posted by s2k_335i

Do you have procede? If so try a different map. Also try to change your spark plug. I had misfire last year and the spark plugs took care of the issue.

I have tried three different map releases including 12-17 with the same issue and same frequency.

I will check my spark plugs again to see their current condition and post my findings.

I do not know which cylinder the misfire is on but I can clearly hear poping coming from the turbo/downpipe which I have corrolated to being unburnt gas igniting from the downpipe and turbo temp, does this sound right? I do not have any codes on the procede to help guide me.

Also it seems to be more prominent when the engine is warmed up.

I will also try swapping coils around to see its effect and report back.

HPFP should be good since it was just replaced but that's not always the case. No codes are making me think its the injectors but maby, no real way to check that.

[tibra1]

Curious how u have all those misfires and no misfire codes or limp mode..does your piggy suppress the codes?? are you sure they are misfires..n not something else going on

I had one misfire then codes and limp immediately thrown..swapped the coil packs from bank 1 to bank 2..cleared the codes n the problem didnt reoccur..

[Brey335i]

Did you plug your o2 sensors back in? I knew a guy who forgot and the small open hole in each downpipe made the car sound like a boat at idle and those noises could easily have been mistaken for misfires.

Just a thought...

[Streetluger06]

Ya I have all 4 sensors in my downpipes. They made it a pain to get the downpipes in!

I'm pretty sure its a misfire, I can feel it when I'm in the car also.
Its like the engine is stumbling, it shakes a little each time it happens then returns to normal idle. I'll check to see if the procede is covering a code up but I don't think it would erase that kind of a code.

What else could it be?

[Brey335i]

This is strange... the Procede wouldn't delete a misfire code. But it does sound a lot like a misfire

[acdHQK713K]

Originally Posted by Streetluger06

Ya I have all 4 sensors in my downpipes. They made it a pain to get the downpipes in!

I'm pretty sure its a misfire, I can feel it when I'm in the car also.
Its like the engine is stumbling, it shakes a little each time it happens then returns to normal idle. I'll check to see if the procede is covering a code up but I don't think it would erase that kind of a code.

What else could it be?

I have the exact same problem. As the car starts to warm up and the idle RPM begins to drop it stumbles and shakes the car. All of this while in park in my driveway. Once it settles at around 600 RPM it's fine.

No misfire codes, no stumbling while on throttle. No popping noises. I have no explanation for it either. Spark plugs have <3k miles on em.

[tibra1]

Originally Posted by Stangorang

I have the exact same problem. As the car starts to warm up and the idle RPM begins to drop it stumbles and shakes the car. All of this while in park in my driveway. Once it settles at around 600 RPM it's fine.

No misfire codes, no stumbling while on throttle. No popping noises. I have no explanation for it either. Spark plugs have <3k miles on em.

I have this too on cold start only..like u hear the engine mis here and there but like u as soon as the idle settles down..no issues..i am pretty sure this is normal

I think the OP has issues at idle even fully warmed up???

[acdHQK713K]

Originally Posted by tibra1

I have this too on cold start only..like u hear the engine mis here and there but like u as soon as the idle settles down..no issues..i am pretty sure this is normal

I think the OP has issues at idle even fully warmed up???

Mine was a new phenomenon about a month ago. Doesn't bother me, just odd.

[tibra1]

Really I have had it since mile #1....i def dont like it and stare eagerly at the dash just waiting for a code to pop up..LOL

[acdHQK713K]

Originally Posted by tibra1

Really I have had it since mile #1....i def dont like it and stare eagerly at the dash just waiting for a code to pop up..LOL

This car likes to ruin my weekends with bullshit codes

[s2k_335i]

I been having Procede for a while now. I always have the code for misfire. I am not sure why your Procede does not have a code.

[tibra1]

Originally Posted by s2k_335i

I been having Procede for a while now. I always have the code for misfire. I am not sure why your Procede does not have a code.

So your sayin its normal to have misfires w Procede..>????

[Tzu]

I had idle stumbling. I cleaned my valves, stumbles/misfires at idle are gone.

[s2k_335i]

Originally Posted by tibra1

So your sayin its normal to have misfires w Procede..>????

You misinterpret my comment. I have Procede and I know when I have a misfire because my laptop tell me so....

[pzco]

my car stumbles about once every ten seconds or so at idle. not sure if misfire does it even after warm up.