[webbdylan335]

So I recently purchased a 2008 BMW 335i with 75,000 miles. It is in great condition and only has a minor oil leak from the thermostat on the oil filter housing, which I am planning to fix in a few days. When I was driving the car already warmed up it drives perfectly fine and no stutters or weird sounds. Cold starts are perfect as well with no stutters or jumps either. The thing that I noticed that is weird is that on warm starts when the oil is already heated up the car will stutter but not violently and has noticeable misfires but doesn't throw a service engine light. On random warm starts of this exact nature it will throw a service engine light for cylinder 4 misfire. I had a old spark plug and coil pack laying around from my older e90 that had about 95,000 miles on them and swapped them in to the cylinder 4 that was giving me issues and it worked for about a week and a half but then still threw a code on me yesterday. I'm starting to think it is injectors but I ordered 6 new ngk spark plugs and 6 new Delphi coil packs to see it it will help before I resort to injectors. Any suggestions of anything else or more major that could be wrong?

[Fritzer]

Might as well do a full coil/plug replacement before you doing anything else. Besides that, has the engine ever been walnut blasted? I would consider doing that as well to clean the valves up, notorious carbon build-up spot. You can find it done for around $200-$300.

[webbdylan335]

Originally Posted by Fritzer

Might as well do a full coil/plug replacement before you doing anything else. Besides that, has the engine ever been walnut blasted? I would consider doing that as well to clean the valves up, notorious carbon build-up spot. You can find it done for around $200-$300.

Ok I will update after I do the spark and coil replacement. I have the tools to do walnut blast too just a pain for how long it takes. I have to take the manifold off for the OFHG so I might as well walnut blast as well.

[TheMidnightNarwhal]

Originally Posted by Fritzer

Might as well do a full coil/plug replacement before you doing anything else. Besides that, has the engine ever been walnut blasted? I would consider doing that as well to clean the valves up, notorious carbon build-up spot. You can find it done for around $200-$300.

Man over here it's 650$

Really wanted to do it but I think I won't do it until I get issues, or keep searching haha.

[Fritzer]

Originally Posted by TheMidnightNarwhal

Man over here it's 650$

Really wanted to do it but I think I won't do it until I get issues, or keep searching haha.

That's only $488 is US bucks though! Regardless, everything seems more expensive up North. I saw some pictures of your grocery store prices for things like milk and beef and was astonished.

[TheMidnightNarwhal]

Originally Posted by Fritzer

That's only $488 is US bucks though! Regardless, everything seems more expensive up North. I saw some pictures of your grocery store prices for things like milk and beef and was astonished.

Haha yeah I know. It's overall more costly.

But I did some research in Montreal, 2 hours from me and apparently some people are doing it for 350$ - 400$, let's hope it's still that.

I should probably remove my manifold and take a look at them though after winter and see if they are actually super dirty or not before getting it done.

[webbdylan335]

yeah I have a catch can installed but I didn't clean the valves before putting it on it was more to prevent further coating of those poor valves lol

[arkie6]

Originally Posted by webbdylan335

So I recently purchased a 2008 BMW 335i with 75,000 miles. ... When I was driving the car already warmed up it drives perfectly fine and no stutters or weird sounds. Cold starts are perfect as well with no stutters or jumps either. The thing that I noticed that is weird is that on warm starts when the oil is already heated up the car will stutter but not violently and has noticeable misfires but doesn't throw a service engine light. ... I'm starting to think it is injectors ...

That sounds very similar to my issue a while back. New index 12 injectors fixed it. See my thread on this for more info:

https://www.e90post.com/forums/showthread.php?t=1459075

[AandSC]

I had similar issue and it was an injector. Changed just the one injector and it’s been running fine since.

[webbdylan335]

Originally Posted by AandSC

I had similar issue and it was an injector. Changed just the one injector and it’s been running fine since.

What index injector did you buy to replace the faulty one? I’ve been trying to find out wether or not I can just replace one or if I have to do all 6. I’m pretty sure my injectors are under index 10 but I haven’t been able to look yet. Hopefully they are index 11 because in Carfax it does show some were replaced before I got the car around 20k miles. If they are index 1-10 I need to find somewhere to buy one. Lmk if u have suggestions or what you did.

[AandSC]

Originally Posted by webbdylan335

What index injector did you buy to replace the faulty one? I’ve been trying to find out wether or not I can just replace one or if I have to do all 6. I’m pretty sure my injectors are under index 10 but I haven’t been able to look yet. Hopefully they are index 11 because in Carfax it does show some were replaced before I got the car around 20k miles. If they are index 1-10 I need to find somewhere to buy one. Lmk if u have suggestions or what you did.

I bought a rebuilt index 7 off eBay and replaced just the one injector. That was a couple thousand miles ago and no issues since. My 335 is a project to see how little I can spend to drive a really nice car so I’m always looking for the cheapest fix. Understand I may have to move to index 11s at some point in the future.....

[webbdylan335]

Originally Posted by AandSC

I had similar issue and it was an injector. Changed just the one injector and it’s been running fine since.

Where did you buy your injector?

[webbdylan335]

Originally Posted by AandSC

I bought a rebuilt index 7 off eBay and replaced just the one injector. That was a couple thousand miles ago and no issues since. My 335 is a project to see how little I can spend to drive a really nice car so I’m always looking for the cheapest fix. Understand I may have to move to index 11s at some point in the future.....

I was thinking about buying a remanufactured index 9 on eBay but I was skeptical to the reliability of it and if it was going to mess up the actual engine. I saw that injectors are one of the few ways to actually kill an n54 so I’m scared to do so. Who did you buy it from?

[AandSC]

Originally Posted by webbdylan335

I was thinking about buying a remanufactured index 9 on eBay but I was skeptical to the reliability of it and if it was going to mess up the actual engine. I saw that injectors are one of the few ways to actually kill an n54 so I’m scared to do so. Who did you buy it from?

The ebay seller was 1-888-9-parts-1. He has a bunch of injectors listed, including for example an index 9 for $70 shipped. I bought it in January, so almost a year with no problems. I haven't even coded it yet, but I plan to do that soon. I don't think there's any way to screw up your engine by removing and replacing an injector.

[Josegut303]

Hello I have a 2011 Bmw 335i e90 with the N55 engine. Every time I cold start the car it misfires on random/multiple cylinders. I've read the codes with a obdll but it doesn't tell me why it is misfiring. I let the engine warm up a little and the misfires completely stop. There's time where I've cleared the codes as well and the car runs like nothing is wrong. But again today i cold started it up and it began misfiring like crazy. Note there are a couple things in my head i believe may be the problem. I recently changed my spark plus some NGK's from autozone. Also when i unlock my car the tail lights and halos don't turn on anymore. So maybe it's the battery since i hear it can affect the fuel pump and lead to misfires but the weird part is i checked the battery with a battery tester and the volts are 12s off and 14s on but when the lights don't turn on when unlocked i heard is like a straight away sign the battery is going bad. I also have had times where i stop the get gas and when i get back in to turn it on the car is completely dead. The car only has 49k miles so i doubt it's the fuel injectors any ideas.? Please help.