[Chriztofor]

About 1 week ago I started having rough idle upon start-up only. After 10 seconds it would go away. No check engine light or any other warnings. Without thinking of this minor annoyance, I decided to check my air filter. Turns out it was ORIGINAL So I changed it and I also deleted the carbon filter. I then added chevron techron fuel system cleaner. http://www.chevron.com/products/prod...tives/tcp.aspx I just noticed that I no longer have that cold start-up rough idle problem. Not sure if it was the air filter, carbon filter delete, or the fuel system cleaner. If I had to guess it would be the fuel system cleaner because BMW in the e90 eliminated the huge gas filter cylinder that was located on the under-body of the e46 and our injectors are probably starting to get clogged. By the way, a good DIY for air filter change and carbon delte can be found here http://www.e90post.com/forums/showthread.php?t=21590 Good luck.

[Verbiage]

Looks like Aonarch was right!

[mike3000fl]

looks like ill try this too. 112,000 miles and it surely needs it.

[Chriztofor]

^ I got the idea from Mike

http://www.e90post.com/forums/showthread.php?t=385766

[vasillalov]

Originally Posted by Chriztofor

I then added chevron techron fuel injector cleaner.

Make sure you change your oil ASAP. Fuel injector cleaners will completely obliterate your engine oil.

[Alexander]

Originally Posted by Chriztofor

^ I got the idea from Mike

http://www.e90post.com/forums/showthread.php?t=385766

NO!!!!

Lol. I say this every day to guys. The N52 needs injector cleaner every oil change, BMW actually recommends it and sells their own bottle. I have no idea if their stuff is any good I just use any major brand that looks good. The charcoal filter is retarded, also I'd remove the silencer as well, it's pointless and prevents air flow.

You should clean your MAF too.

Super, super easy. Torx 25 or 27? Two screws, then spray like 20 times 1 seconds a spray wait 5 seconds spray...

[Alexander]

Originally Posted by vasillalov

Make sure you change your oil ASAP. Fuel injector cleaners will completely obliterate your engine oil.

Never heard that, but you might be right. I'd do it before an oil change regardless if it kills the oil, it's just smart.

Also the fuel injector cleaner with octane booster is good shit.

[John 070]

Originally Posted by vasillalov

Make sure you change your oil ASAP. Fuel injector cleaners will completely obliterate your engine oil.

Is that true? I figure in the modern era these additives are not needed. Also, the dealership should have changed the air filter, mine got done with very low miles, forgot when, < 10k. I had taken it out to look prior, and it looked like it was brand-new out of the box, so not sure why it got changed.

[Alexander]

Originally Posted by John 070

Is that true? I figure in the modern era these additives are not needed. Also, the dealership should have changed the air filter, mine got done with very low miles, forgot when, < 10k. I had taken it out to look prior, and it looked like it was brand-new out of the box, so not sure why it got changed.

BMW recommends it every 6,000 miles. It helps clean the VANOS as well as the fuel injectors. It seems like fuel injectors are starting to go bad upwards of 80,000 miles form some of the posts that I've seen.

Preventative maintenance is key in keeping your E9x running smoothly w/o issues.

[Alexander]

Silencer removal DIY

http://www.e90post.com/forums/showthread.php?t=37835

[CollinsE90]

Originally Posted by vasillalov

Make sure you change your oil ASAP. Fuel injector cleaners will completely obliterate your engine oil.

+1, he beat me to it...you always want to change your oil right after a fuel injector cleaner

[Chriztofor]

Nice suggestions.

I didn't know that the oil needed to be changed after using injector cleaner, just great, I had the oil changed 2,000 miles ago. Oh well. Thanks for the heads up.

Silencer delete, hmmmm, might do that.

[JIM E92]

Also added a full bottle of Techron Fuel System Cleaner on 3/4 tank. By the time I was at half tank the rough idle went away. I'm very impressed.

BTW last week Oriley's was having a buy one get one free on Techron.

[Chriztofor]

Originally Posted by JIM E92

Also added a full bottle of Techron Fuel System Cleaner on 3/4 tank. By the time I was at half tank the rough idle went away. I'm very impressed.

BTW last week Oriley's was having a buy one get one free on Techron.

Nice! By the way, I contacted chevron and you do not need to change the oil unless you add the injector cleaner more than 5x? I posted an email from Chevron some time ago. Too tired to look for it now.

[Chriztofor]

Sorry for revivng the thread. I saw a flag and I thought it was a recent comment! lol