[racerg35335]

Hello all. Thanks in advance for any responses that may help me diagnose my problem. My car is a 2007 e92 335i with 47k miles. Original plugs as I have recently purchased the car

Just before I was flying out of town last week my car picked up what I am assuming is a misfire (and the service engine light came on). I have not been home in order to have diagnostics run on it nor do I want to spend the money on a BT tool b/c I plan to pick up a JB4 soon. Currently my only mod is a jb+ only intsalled a few weeks ago.

I went WOT at about 3k and just as boost was building the car picked up a misfire. Almost a vibration. It continued to do this under normal driving and the CEL came on. I turned the car off and restarted with the same problem. Basically, it feels like I am on 5 cylinders. I went ahead and ordered plugs and a coilpack that should be on my doorstep when I get home. I am just hoping it is not an injector or worse. Has anyone experienced the same problem? Would a plug or coilpack go out all at once like that? I have had bad coilpacks on other vehicles and it felt like they would go on and off before they went bad completely. I am on vacation and just wanted to get an idea of what i will be dealing with when i get home. Any other ideas as to what it may be? thanks again.

[335xi Kevo]

sounds more like injectors my friend. Just went through the same song and dance. Definitely good to start with coils/plugs tho. Its one of the 3.

[racerg35335]

Yea thats what I was afraid off. I would think a plug/coilpack would give warning and/or only misfire under load as it started going bad. Considering, it happened all at once I was afraid it was an injector. I can install an injector myself but can't code it. I really dont want to spend $250 in labor alone for an install. Only had the car a few months and already had to put a new agm battery, tires, oil change, ann alignment. This thing is getting expensive quick. I'd rather be spending it on mods!

[cstavaru]

Sounds like the high pressure fuel pump to me. I had very similar symptoms like 2 years ago when my HPFP was replaced under warranty.

[racerg35335]

Really? I had not thought of that. I was not aware the hpfp would cause those symptoms. I'll find out when I have the diagnostics run but it is driving me crazy being 1000 miles away from my car and having no idea what is wrong with it. Also, I dont know how much money I should hod back while on vacation. lol. At least it would be under warranty if it were the hpfp but I would have to buy a bt tool to be sure the jb+ didn't throw any tuner codes at 50%. Either way $$$$$

[smolik]

hpfp puts you in limp mode. coils, plugs, injectors.

[Gugs]

Sounds like nothing actually. Sounds like you should just read the codes instead of pissing in the wind. The answer is in there clearly so why make wrong assumptions.

Sounds like u have bad vanos sensor, possible bad lamada and 100 other common problems.

Read the code and get back that's the only way to solve anything.
Boggles my mind u order parts when not even home, and every autoZone will read ur car for free in this country. Along with most other auto part stores.


But yea order parts for a problem that u don't what it is and have no idea what u need. Lol

[racerg35335]

Considering the car has 47k miles on it the plugs needed changed anyhow. I planned on doing that before the jb4 in a few weeks. Also, it is not a bad idea to have a coil on hand because I am sure I will eventually need it. I would like to have the parts there when I get home so I can fix it same day rather than waiting for shipping times. It is my daily driver. Hope it makes a little more sense to you now. But actually was not aware that autozone could read codes on our cars so thank you for that piece of information.

[racerg35335]

Not sure why anyone would think it a bad idea to have maintnance items on hand. Lol. But that's just me.

[racerg35335]

Well it was a #1 cylinder misfire. Luckily I already have a coil and the plugs should be here tomorrow. Just hoping its not an injector, I spent too much money on vacation.. Thanks for the replies!

[benzy89]

If the new plug & coil doesn't fix it, it's possible that you need to get your intake valves cleaned. Dirty valves can cause misfires & if you've never had them cleaned, at 47k you're right in middle of when most people get them cleaned (45-50k)

[tmurphy2]

just went through the same shit. plugs, injectors, coil packs, in that order. if that doesnt work then you are screwed. then you are into valve cleaning (unlikely) HPFP LPFP and suicide. but to be honest doing the first three id say its a 90%+ chance it will fix it.

your car may be covered under the injector recall...look into that, and if it is an injector warrenty will cover it just remove tune. and even if they didnt its like $200 dont sweat.

[Wedge1967]

I don't disagree with everyone, but as you increase boost, you're taking a chance with an old set of plugs are the cause of the misfire. Regardless of what tune you end up with, do yourself a favor and replace the plugs. When you gap the plugs, reduce the gap so the ignition doesn't have to work as hard under load. Have fun and good luck.

[racerg35335]

I thought the plugs came pre-gapped. How much do you recommend reducing the gap by? Thanks for the advice!

[benzy89]

Originally Posted by racerg35335

I thought the plugs came pre-gapped. How much do you recommend reducing the gap by? Thanks for the advice!

If you buy the Bosch plugs, they're pre-gapped +are essentially the same as the OEMs. Only difference is they say "Bosch" instead of "BMW" on them

You can buy them cheap from here http://www.autohausaz.com/

[racerg35335]

Yea I have the Bosch plugs on the way. They should be here tomorrow. Should I still close the gap on them? If so by about how much. Thanks again.

[benzy89]

They're perfect as is, with an aggressive tune you'll just go through plugs faster then if you were on the stock performance setting