[DriveSchnell]

I have a 2007 335 with about 80K miles. I recently had the turbos replaced under the extended warranty for wastegate rattle issue.

I am experiencing a very slight surging under light and constant acceleration. Its barely noticable, but noticable enough to be an annoyance and makes me wonder what is wrong.

I was running JB4 tune for awhile but turned it off because I ruined an ignition coil on heavy acceleration at high speed. A month or so later, I accellerated quickly from a stop and experienced the same issue where the engine is shaking violently due to one of the cylinders not firing. However, after I stopped the car and restarted the problem went away. I turned the JB4 off at that point thinking that it was causing the problems and have been driving the car with less enthusiasm since. Not sure if these issues are related to the surging and not sure if the JB4 was causing the problem with the ignition coils...

So, my questions:

1) Can the JB4 be causing issues with the engine?
2) If the surging is not related, could it be fixed with replacing the spark plugs? How about walnut blasting?

Thanks.

[galahad05]

1) Yes, but usually in the form of "higher power = showing weaknesses in the engine/fuel/ignition system easier than stock". So if you have borderline-weak spark or carbon deposits on your intake valves, for example, you'll notice it real quick when you have the boost turned up. Stock, less so.
2) Walnut blasting fixed my problems. General rule of thumb these days seem to be walnut shell blasting is needed about every 60k miles or so. Some get away with more--even up to 100k miles. I had mine done at 65k miles.
Spark plugs really should be something around a 60k miles change for a 335 (stock) or ~30k miles (boosted).

[335m]

Have you cleared/read any codes from it recently?

[DriveSchnell]

Originally Posted by 335m

Have you cleared/read any codes from it recently?

I have not received any codes in the dash, but will scan later.

[DriveSchnell]

Originally Posted by galahad05

1) Yes, but usually in the form of "higher power = showing weaknesses in the engine/fuel/ignition system easier than stock". So if you have borderline-weak spark or carbon deposits on your intake valves, for example, you'll notice it real quick when you have the boost turned up. Stock, less so.
2) Walnut blasting fixed my problems. General rule of thumb these days seem to be walnut shell blasting is needed about every 60k miles or so. Some get away with more--even up to 100k miles. I had mine done at 65k miles.
Spark plugs really should be something around a 60k miles change for a 335 (stock) or ~30k miles (boosted).

Thank you! Will look to do both.