[slim_n54]

So I've got a 2010 335i which I bought used in 2014. Already had the M-Performance exhaust on it and I added just a dual cone intake from Cobb. I also had tuned the car with the Accessport for a brief period of time around when I got the car around 40k miles. I'm now at 105k (tune has been off for years)...

I've had my car in the shop (not dealer) a few times the past month with the service engine light on and they believe it to be injectors as everything else has been replaced recently. They say there was a bulletin to have the injectors replaced under extended warranty until 120k.

So my question is... Would you worry/take the time to swap out the intake filters with the factory airbox simply so the dealer doesn't dig too deep into the ECU and find out it's been tuned, or not worry about it? Yes I know there's a good chance they can see it anyhow, just curious if it's worth putting the old airbox back on so the possibility that it's been tuned isn't so assumed by them?

Any opinions very helpful! Thanks!

[RocketSurgeon]

It depends on the dealer, but I would always go 100% stock before service (especially a warranty claim). Being a 2010, there's a good chance you have the extended warranty on injectors. I just tested the injectors on a 2008 and found 2 leakers, one index-5 and one index-9. I doubt the old tune would be an issue, they would have to dig into FASTA data, and they have no reason to do that.
What issues are you experiencing that lead to the injector diagnosis?

[slim_n54]

Originally Posted by RocketSurgeon

It depends on the dealer, but I would always go 100% stock before service (especially a warranty claim). Being a 2010, there's a good chance you have the extended warranty on injectors. I just tested the injectors on a 2008 and found 2 leakers, one index-5 and one index-9. I doubt the old tune would be an issue, they would have to dig into FASTA data, and they have no reason to do that.
What issues are you experiencing that lead to the injector diagnosis?

Thanks Rocket! I've been flirting with the service engine light the last few months. I've had a rough idle (car then proceeds to just about stall as the RPM's lower back down after starting it) and definite power loss, with the car sputtering as I pick up speed (only when driving hard of course).

I've replaced the plugs/coils a few times and things had improved a good bit but seemed to be back again. Codes say "Bank 1 too lean", shop swapped bank 1 and bank 2 injectors and the issue stayed in bank 1, and they claim it to be the injectors needing replaced this time.

[jt335i]

I have a 2010 E92 335i and is currently at 98,200+ miles on the ticker. Bought it new and it is covered by the 120K warranty. As of today, I haven’t had any issues with the injectors. My 335’s mods is similar to yours. In 2016, I replaced the OEM mufflers with the BMW PE, added a Cobb tune stage 2, and swapped the OEM air filter with a K&N drop in. I didn’t mess with replacing the stock air box with any kind of aftermarket CAI because the stock intake is already a CAI.
I have an Indy BMW mechanic that does all my maintenance and services and have not brought my car to the dealer for any other services besides the free oil change period and recalls (i.e. HPFP, battery cable, driver side airbag).

As for the injector warranty, you need to carefully read the terms. If it doesn’t mention anything about performance mods or anything that suggests tampering with the engine (i.e. aftermarket tune, etc.) which will void the warranty, then there’s nothing you should worry about. If you’re not sure, then you should call BMWNA to clarify. There is a discussion thread on this injector subject that you can read through for useful information. The most recent post is as of 4/28/2018.

http://www.e90post.com/forums/showth...1209808&page=8

You can also go to an independent BMW mechanic to have it done and get reimbursed for the replacement. This is also mentioned in that thread about folks getting theirs done and applying for reimbursement.

[slim_n54]

Originally Posted by jt335i

I have a 2010 E92 335i and is currently at 98,200+ miles on the ticker. Bought it new and it is covered by the 120K warranty. As of today, I haven’t had any issues with the injectors. My 335’s mods is similar to yours. In 2016, I replaced the OEM mufflers with the BMW PE, added a Cobb tune stage 2, and swapped the OEM air filter with a K&N drop in. I didn’t mess with replacing the stock air box with any kind of aftermarket CAI because the stock intake is already a CAI.
I have an Indy BMW mechanic that does all my maintenance and services and have not brought my car to the dealer for any other services besides the free oil change period and recalls (i.e. HPFP, battery cable, driver side airbag).

As for the injector warranty, you need to carefully read the terms. If it doesn’t mention anything about performance mods or anything that suggests tampering with the engine (i.e. aftermarket tune, etc.) which will void the warranty, then there’s nothing you should worry about. If you’re not sure, then you should call BMWNA to clarify. There is a discussion thread on this injector subject that you can read through for useful information. The most recent post is as of 4/28/2018.

http://www.e90post.com/forums/showth...1209808&page=8

You can also go to an independent BMW mechanic to have it done and get reimbursed for the replacement. This is also mentioned in that thread about folks getting theirs done and applying for reimbursement.

Thanks JT! I actually just had it at an independent BMW/Benz shop who told me about the bulletin, otherwise I never would have known. They verified the extended warranty through the dealer and recommended me putting the old air box back on to avoid the questionable tampering. I haven't been able to find the actual bulletin, just a few re-posts on forums. I've got an appointment this week to have them done as well as the airbag so I'll likely just swap it out. Thanks again for your reply!