Need some help diagnosing idle pulse/ slight surging

[09GT]

I have a 08 E90 6MT, 38K. Yesterday upon start up it, the exhaust seem to pulse at idle, and the car seem to surge a bit will driving in traffic. Sure enough this morning it did the same thing and I got "Increased Emissions" CEL. I haven't had the specific code read and my car is out of warranty, so I'm trying to get an idea of want it might be before I take it in.

Seems like its either a o2 sensor or some other fuel sensor. Any ideas? Car drives pretty normal, no decreased redline. Read through some threads, but couldn't find anything about the exhaust pulsing at idle.

Lucky we have some good private BMW mechanics in Chicago, so no need to get hit with the high dealer rates.

Thanks ahead of time for any help guys.

[09GT]

Also, no mods, no tune.

[09GT]

This sounds pretty crazy, but found this thread:

http://www.m3post.com/forums/showthr...ased+emissions

"UPDATE** Got my car back from the dealer. The paperworks says the reason for the check engine like (increased emissions) was caused by after market wheel. I WAS LIKE WTF?!?!? Are you kidding me?

This is exactly what it says and I will take a picture of the paperwork later tonight:

Aftermarket accessories connected charger and interrogated fault memory and found due: Speed recording default. Followed test plan and wire tested the system between the DME and DSC. Found the PT can line to be fully operating at 1.5 volts and 4 volts high. Found the resistance to be at. 020 HMS. Wrote puma case 50847390 and they advised me to measure the wheels on the car verse the stock wheels. Found the rear wheels to be 63.5 MM difference and 18.24 mm in the front. Found the trans shifting to also be related due to the weight nd size of the wheels. Per puma swapped stock wheels and cleared faults drove car and found the light to not be present. Found the wheels to be the problem for check engine light."


Honestly, ever since I swapped my summer wheels back on (recently purchase, used). The car has been driving kinda pissy (surges more than usual). The ratio from front to rear (245/30/20 & 285/30/20) is 3.7% difference. I think I'm going to buy some 295/25/20's, but could this really cause a problem with a manual trans? I guess I will throw my winter wheels back on and see if that fixes the problem.

[happos2]

Did you get your codes read?

If you are pulsating at Idle and in neutral, you are not connected to the drivetrain. It doesn't matter which wheels you have at that point. You could be on 46" mudders, you can have the wheels off and it wouldn't matter. There is some other underlying affect. Having different sized wheels/tires with an overall different diameter can cause problems while moving down the road (speedometer not correct for instance).

You mentioned you had an 08 which have had some throttle acuator problems, but I am not sure what this would cause or if it is even remotely related.

[09GT]

I'm going to head to AutoZone after work.
I noticed there is a lot of talk about Idle Valves and the Throttle Actuators.
The Actuators seem to be very expensive to fix, which sucks.

Originally Posted by happos2

Did you get your codes read?

If you are pulsating at Idle and in neutral, you are not connected to the drivetrain. It doesn't matter which wheels you have at that point. You could be on 46" mudders, you can have the wheels off and it wouldn't matter. There is some other underlying affect. Having different sized wheels/tires with an overall different diameter can cause problems while moving down the road (speedometer not correct for instance).

You mentioned you had an 08 which have had some throttle actuator problems, but I am not sure what this would cause or if it is even remotely related.

[happos2]

Can autozone or the likes read manufacture codes? Or can they only do the generic ones...

[09GT]

I thought they could.
Theres also a good shop by my work I might stop by as well.

Originally Posted by happos2

Can autozone or the likes read manufacture codes? Or can they only do the generic ones...

[09GT]

Update:
Went to Autozone, they scanned it for free.

P0305, cylinder 5 misfire

I already bought some new spark plugs, just haven't installed them yet, guess I will now.
Suppose it could be a ignition coil. I only found 1 other member that had this error.

[edwinm3]

Originally Posted by 09GT

Update:
Went to Autozone, they scanned it for free.

P0305, cylinder 5 misfire

I already bought some new spark plugs, just haven't installed them yet, guess I will now.
Suppose it could be a ignition coil. I only found 1 other member that had this error.

ign coil

[09GT]

Here is a pic of my spark plugs after 38K.
They don't look great, but would this cause a misfire?

[happos2]

Test them!

[09GT]

Replaced all the spark plugs and reset all the adaptations.
Car runs like new, hopefully that's it.

[edwinm3]

Originally Posted by 09GT

Replaced all the spark plugs and reset all the adaptations.
Car runs like new, hopefully that's it.

They look like shit lol. Glad it's fine

[09GT]

So the car drove great for a day, then started misfiring again on start up/ cold start. There is also so very mild shaking at low rpm's in a high gear.

I have a feeling the mechanic never tested the coils. He said they looked fine/ OEM BMW spec.

Wondering if I should just go to a BMW dealer out in the suburbs and have them look at it. Some of these private mechanics don't see enough M's to properly diagnose them.

What do you guys think? Ignition coil? Software update needed? Fuel injector? I just don't want to throw money away guessing.

[edwinm3]

At least you know it's not the plugs. Has to be a coil

[09GT]

I think I need to take it over to Patrick BMW.

I talked to the mechanic who did the plugs, he said he switched the ignition coils around to test them, but I'm still misfiring on cylinder 5.

What else could it be? Bad connector? Old software? o2 sensor? Vacuum leak? Fuel injector?

Could use some opinions before getting raped by the dealer???

[SYZ]

Originally Posted by edwinm3

They look like shit lol. Glad it's fine

Unless my monitor setting are jacked up, those plugs definitely don't "look like shit" to me. They look like normal wear.

[SYZ]

On cold start, the motor is running in open loop, correct? So wouldn't that eliminate the possibility of the o2 sensor? Sounds like a coil or some other sensor to me.

[Gooch]

I had a similar problem . But the misfire was so seldom that it would take a while for it to trigger the service light. I moved the coil to another cylinder. Once I saw the misfire code change location I knew that was the issue. The coil was cheap online.

[09GT]

Took it to the dealer today, but no real luck. Customer service was excellent though. They did find a small vacuum leak in the air filter case (not shut properly). SA says the P0305 code a registered 12 times. They suggested to run the gas out of it first and refill at a good gas station before they look any further. Quote for replacing a coil was over $400.

Interestingly enough I did actually fill up at a shady Speedway gas station last time.

Is there any sensors connected to the ignition coil, itself that could cause this?

If the dealer keeps poking around this could get expensive.

Also, they noted the car's current software is 2.45.2, but the latest update is 2.49.2 (thought it was 240). Software update was $248.00.

[09GT]

Nevermind, found this:

220E:
ISTA/P;2.43.2;E89X-11-09-503
ISTA/P;2.44.0;E89X-11-09-505
ISTA/P;2.45.0;E89X-11-09-506
ISTA/P;2.45.1;E89X-11-09-506
ISTA/P;2.45.2;E89X-11-09-506

231E:
ISTA/P;2.46.0;E89X-12-03-500
ISTA/P;2.46.1;E89X-12-03-502
ISTA/P;2.46.2;E89X-12-03-502
ISTA/P;2.46.3;E89X-12-03-502
ISTA/P;2.46.4;E89X-12-03-502
ISTA/P;2.47.0;E89X-12-07-502

240E:
ISTA/P;2.47.1;E89X-12-07-503
ISTA/P;2.47.2;E89X-12-07-504
ISTA/P;2.47.3;E89X-12-07-504
ISTA/P;2.47.4;E89X-12-07-506
ISTA/P;2.47.5;E89X-12-07-507
ISTA/P;2.47.6;E89X-12-07-507
ISTA/P;2.47.7;E89X-12-11-507
ISTA/P;2.48.0;E89X-12-11-507

[09GT]

Follow up.
Had the ignition coil replaced and the car is running like a champ!