[yungcole]

2009 335i x drive. I recently installed a dual cone intake, I dont know if thats related to this or not, but the night I installed it a couple hours later my light came on and it was strongyl vibrating. I restarted the car and it was gone. Now today driving home from work the car went half engine power mode and has a strong vibration coming from the engine. Is it spark plugs? Fuel injectors? Miss fire? Please help.

[jt335i]

Well, if your car was running perfectly fine before you installed the DCI, then obviously something went wrong during or after the installation. Maybe something wasn’t connected right and a sensor is not reading correctly or there could be some kind of defect with it. We really can't help you unless you get a OBDC code reader to hook up to your car or bring it to a BMW shop or auto parts store than can do that.

The stock air box is already a free flow CAI so adding a DCI isn’t really going to add much HP, minimal HP at best, that you will really feel because it will be sucking in hot air from the engine bay. The only thing you’re getting out of it for your money is just sound. You can try putting back the stock air box and see if the problem comes back. If that happens again with the stock, then there’s something with engine that you need to have checked.
If its fine with the stock, then leave it in and swap out the stock mufflers with a BMW PE.

[robthewrench]

If you don't find something obviously un-plugged, your next best step is to scan the codes and find out what is not working.

[Meeni]

Maybe you disconnected the MAF sensor. If you used an oiled type of filter maybe you put too much and your MAF is now contamitated (destroyed) and will need replacement. Or you moved the intake tubes and let an air leak post-MAF.

[yungcole]

Just needed a new coil. Cylinder 3 was missfiring like crazy and had to be replaced. Damn shame I bought her at 110,000km and it still has original coils and spark plugs lol

[yungcole]

Originally Posted by Meeni

Maybe you disconnected the MAF sensor. If you used an oiled type of filter maybe you put too much and your MAF is now contamitated (destroyed) and will need replacement. Or you moved the intake tubes and let an air leak post-MAF.

I made sure to oil it perfect! Could my intake possibilily have caused me to get a new coil? Or was it pure coincidence that it started missfiring around the same time as the intake install.

[yungcole]

Originally Posted by jt335i

Well, if your car was running perfectly fine before you installed the DCI, then obviously something went wrong during or after the installation. Maybe something wasn’t connected right and a sensor is not reading correctly or there could be some kind of defect with it. We really can't help you unless you get a OBDC code reader to hook up to your car or bring it to a BMW shop or auto parts store than can do that.

The stock air box is already a free flow CAI so adding a DCI isn’t really going to add much HP, minimal HP at best, that you will really feel because it will be sucking in hot air from the engine bay. The only thing you’re getting out of it for your money is just sound. You can try putting back the stock air box and see if the problem comes back. If that happens again with the stock, then there’s something with engine that you need to have checked.
If its fine with the stock, then leave it in and swap out the stock mufflers with a BMW PE.

Yes I'm sucking in hot air, but an engine requires air regardless so I don't mind having a bunch of hot air vs a medium amount of cold air. I love the sound. Is there actual disadvantages of doing dci over stock? Because I'll go back if there is

[jt335i]

Originally Posted by yungcole

Yes I'm sucking in hot air, but an engine requires air regardless so I don't mind having a bunch of hot air vs a medium amount of cold air. I love the sound. Is there actual disadvantages of doing dci over stock? Because I'll go back if there is

From what I understand in reading numerous posts on this subject, and what I got from my trusted BMW mechanic, with a turbo engine, a DCI or any other aftermarket CAI, is not a significant restriction and the ECU isn't going to let any more fuel and air in there to go past it's max designed limit unless you tune it. Getting an ECU tune with a CAI usually can give some HP improvements, but not enough to really feel it so bottom line all you're getting out of it is better sound.
To really get colder air and get more HP gains, put a bigger FMIC.

Going for a downpipe + a tune is usually the next step to allow the turbo to spin faster/higher. A full exhaust with cat-deletes is usually after that to help with the same.

Overall, an intake is usually not worth upgrading unless you've upgraded the turbo/intercooler so that they can flow a LOT more air than the stock, but you better have upgraded other things, like injector width, fuel pump, etc., otherwise you'll fry some/all of the parts.

With that, on my 335, I stuck with the stock air box and swapped the OEM filter for a K&N drop in, replaced the stock mufflers with the BMW PE, and did a stage 2 Cobb tune all by my trusted mechanic.
That's pretty much all I'll do for mods on my ride and I am happy with that.