[BayMoWe335]

Driving to work today and my 335i just started misfiring like hell. At least, I guess that's why it was doing.

NO power, ran like absolute shit (Thought I had a flat tire it was so shaky) and then smelled like absolute shit (Rotten eggs). It was flashing service engine soon.

I managed to pull in to a parking lot and let it sit a while. I restarted it and it smoothed back out. Drove it 3 miles to the shop and they will look at it.

Is it an injector? Coil? Spark plugs? HPFP?

Never had that kind of reduced power before, even when HPFP was bad. This was undrivable.

[catcher22]

Someone said it right the other day. These cars can be the greatest machines in the garage one day, then a complete disaster the next day.

I'm sure the codes will tell you if it's your fuel pump or ignition related. Could be something as simple as a bad coil or as bad as a failing HPFP

[TBN54]

Likely Possibiliies:

Ignition coils
Spark plugs
Injectors

[BayMoWe335]

If it's a fuel pump, don't I need to take it to the dealer for a free one? It's still under warranty for me, right?

2010 E92 335i.

[Antetokounmpo]

Originally Posted by BayMoWe335

If it's a fuel pump, don't I need to take it to the dealer for a free one? It's still under warranty for me, right?

2010 E92 335i.

Misfires are related to the ignition system probably 90% of the time. Sounds like you could just use a fresh set of plugs.

[BayMoWe335]

Originally Posted by Heel Toe

Misfires are related to the ignition system probably 90% of the time. Sounds like you could just use a fresh set of plugs.

35,000 miles. Tuned with Dinan S2 for maybe 30,000 miles.

[XM_Rocks]

None of us are going to be able to tell you.

Get software like a Bav Technic Cable or if you want to have something handy that you don't need a laptop for get a Cobb AP3.

Then the code will tell you exactly what is happening.

I was coming home from a 300 mile business trip at 8pm on a Thursday a few months ago.

Started getting missfires on the highway. Exited the highway and pulled out my Cobb AP3... code was for Cyl # 2 misfire. Seeing as how i have new plugs I called ahead to the next town and they had a coil.

I borrowed tools from the O'Reilly's and had it changed in 30 mins.

Bam car purred again and I made it home fine.

the next week I replaced all of the coils with Bosch coils... even the no name one I just put in because I am anal retentive.

In your case the code would tell you if you need to go to the dealer for HPFP repair or an indie for something else.

[Antetokounmpo]

Originally Posted by BayMoWe335

35,000 miles. Tuned with Dinan S2 for maybe 30,000 miles.

Plugs, plugs, plugs. I get about 10k on a set of plugs before they start misfiring. Running 17-20psi depending on the time of year.

[Fred_Boosted]

OP you have over 1590 posts and can't figure this out?

Anyway, pull code first, then check spark plugs, then check ignition coil.

At 35K miles, sound like plugs to me, since you may never change it before.

[BayMoWe335]

Originally Posted by Fred_Boosted

OP you have over 1590 posts and can't figure this out?

Anyway, pull code first, then check spark plugs, then check ignition coil.

At 35K miles, sound like plugs to me, since you may never change it before.

What are you talking about? I mentioned the 4 things it probably is and I'm not a mechanic, lol. I don't even have the code.

I take my cars to the shop and let them fix it. I'm already pretty sure it's one of the 3 things I mentioned.

I'm trying to get input on other things it might have been, what I should do going forward, and generally vent about problems at 35k miles.

Not like I didn't know this could and would happen...

[mike@x-ph.com]

Do you have a code scanner or tune to read codes?

[sirdaft1]

Read the codes. This will tell you more than anything else.

If you are so inclined to attempt to diagnose and repair yourself (given that you said you take it to the shop for repairs), start with this:

1) With your car running, pull each of your coil packs one by one. If you pull a good coil pack, the car should run noticeably worse once it's removed. If you pull a coil pack and it runs equally as crappy, that means you've found the cylinder that is experiencing the issue. Try swapping that potentially bad coil pack with one on a good cylinder to see if the issue follows the "bad" coil pack. If the misfire follows that bad coil pack, replace it. No coding required. If it does not follow that coil pack, it is likely something else (ie: bad spark plug/injector/etc).

2) If there is no bad coil pack, pull all of your spark plugs. Look at the tip of each spark plug as you pull them. Are any of them wet and smell like raw, unburned fuel? If so, odds are you have a leaky fuel injector. Replace that one bad injector along with the other two injectors on that same bank w/ new index 12 or higher injectors; or just replace all 6 to be safe. DO THIS IMMEDIATELY IF THIS IS THE CASE. You can hydro lock your engine if you continue to drive with a leaky injector. Be sure to have the new injectors coded - either at the dealership or a local coder. www.rockauto.com seems to have some of the best pricing on them.

3) If none of the above, replace your spark plugs and start your car again. If poor idle persists, we've identified that it's not spark plug, coil pack or fuel injector related. And is likely a bad fuel pump issue or possibly something else (vacuum leak, etc). Logging will help identify whether its a bad HPFP or LPFP.

All of the above can be done with very minimal effort. Fortunately your issues are fairly common, so don't overly stress.

[BayMoWe335]

Originally Posted by mike@x-ph.com

Do you have a code scanner or tune to read codes?

No, I'll let y'all know once I get the code read. It's being diagnosed now.

[BayMoWe335]

The weird part is that a complete restart of the car made it run smoothly again...I drove very carefully, but had no issues driving a couple miles to the shop.

Before, it was undriveable.

[XM_Rocks]

Originally Posted by BayMoWe335

The weird part is that a complete restart of the car made it run smoothly again...I drove very carefully, but had no issues driving a couple miles to the shop.

Before, it was undriveable.

Now that you said that my $$ is on HPFP.

[fazman]

Originally Posted by BayMoWe335

35,000 miles. Tuned with Dinan S2 for maybe 30,000 miles.

I do spark plugs every 25k miles on my n54 with FBO jb4 map 5

[fazman]

Originally Posted by Fred_Boosted

OP you have over 1590 posts and can't figure this out?

Anyway, pull code first, then check spark plugs, then check ignition coil.

At 35K miles, sound like plugs to me, since you may never change it before.

My guess is on plugs as well... but it might also be carbon blasting time if you are getting misfires on cyl 5 or cyl 6 (They get the dirtiest first).

[Shane303]

I'm still waiting on photos of a piece of crap... here

i'll start

[bimmette]

Originally Posted by Shane303

I'm still waiting on photos of a piece of crap... here

i'll start

Aw, c'mon it's lunch time here

[TBN54]

For some strange reason, I'm really craving a hot dog.

[grizz311]

Spark Plugs. You've been tuned for 30k. Normal change interval is 45k.

[dawhiz]

I'm going with injectors having just swapped a bank.