[Pavlo335]

Hey guys,

This is my first post so I apologize if I sound like a noob

I wanna start off by saying I purchased my stock 2007 e92 335i 6spd last October and I absolutely love it. Prior to this car I had an e46 330ci 5spd, so the turbo world is new to me. When I first got the car the ses light came on my first day of ownership. It would cold start really rough but then run well once it was warmed up. It had an open recall for the blower motor wiring so I took the car to the dealership for the recall and asked them to check out the engine light while they were at it. They came back and told me the ses was for an evap leak but there were also codes for misfires because the car had a tune and that flashing it back to stock would fix the cold start issue and in turn there would be no misfires. So i said okay go ahead so they flashed it back to stock and then came back and told me that it didn't solve the problem and that my injectors were leaking and quoted me close to 3k for the repair. I said no thank you and took the car to my local indy that i use to take my e46. He told me that my injectors don’t leak and that if they were failing they would either be stuck open or closed and that I just needed new coil packs and plugs, and a new leak detection pump to fix the evap leak. I had all of this done and also had him do a walnut shell blasting. This all made the car run much nicer however the car still had a slight rough idle on cold starts. I called my mechanic and he said that these engines are known for rough cold starts basically that its normal because the carbon build up and even the walnut blasting wont clean all the carbon build up.

So I continued to drive my car and the rough cold starts progressively got worse and the car started to hiccup at idle more often but the ses light wouldn't come on. So now several months and 7k miles later im not accepting the fact that this is normal and something that cant be fixed so I decided to do my own research into this issue which I wish I would have done from the beginning but I came to the conclusion that in fact my injectors were leaking. I didn’t want to take my car back to that indy and i didn’t want to fork over 3k to bmw so I decided I would do the job myself and I ordered myself a set of 6 brand new index 12s from ecs tuning along with the oem bosch ZGR6STE2 plugs and oil and filter. Even though I had just done a change 2k miles ago I was worried that the oil viscosity could be compromised if the injectors were leaking, and what kind of damage i may have done already to my engine driving 7k miles with leaky injectors. When I pulled the first spark plug sure enough it was fouled, wet and smelt like fuel. the first 3 plugs looked pretty bad but the 4,5,&6 plugs looked okay. They actually seemed to progressively go from really bad to okay. I had a weird arrangement of index 3’s, 9’s and one index 8 in the car. After changing the oil, plugs, injectors and coding them with the bmw protool app, the car starts and runs 10x smoother, pulls nicely and never misfires under load, however it still runs slightly rough on cold start and i still get that occasional hiccup at idle, noticeably more when the car is not at full operating temperature. The ses light does not come on but I did get the code 2C7E “oxygen sensor control” the day that I replaced my injectors when I was testing the car after. I cleared the code and it hasn’t come back in the past 3 days since. I was really hoping the injectors would solve all of my issues.

If you read this far I really appreciate you. What do you guys think? Could the coil packs be bad after 7k miles of driving with leaky injectors? Could there really be that much carbon build up just 7k miles after a walnut shell blasting? Could I have done some real damage to the internals by driving so long with leaky injectors? I mean who knows how long those injectors were leaking for.

Any input is greatly appreciated. Thank you to those who took the time reading this.

[BM3Rrrr]

Have you checked your plugs recently after installing the new injectors?
You can also try resetting the lambda adaptations

[Pavlo335]

Originally Posted by BM3Rrrr

Have you checked your plugs recently after installing the new injectors?
You can also try resetting the lambda adaptations

Yes I put all 6 new plugs in with the injectors. Haven’t tried resetting the lambda adaptations but I can try that today. What do the lambda adaptations do exactly?