Help! White vapors + fuel smell + lack of power

[Hotflare]

Question, fellow gearheads...

My M3 has been recently running oddly , with a lack of power similar to a large boost leak on acceleration as well as white vapors from the exhaust that smell of fuel. Car currently has 64k, is on bm3 flex tune (91) running e50-e60 max. Also have the bend flex fuel kit with filter for the last 4k miles ....

Car sounds like a tractor with acceleration, too , so haven't been driving it outside of 5 miles total. Checked for leaks (none) and will take it to my local shop to inspect for boost leaks+change the oil.

Wondering if it could be the infamous stuck injector or a hidden boost leak somewhere, but Car throws 0 codes. Thought of datalogging but don't want to accidentally make things worse.

Advice? T.I.A.

[theweebabySeamus]

Sounds a lot like an injector.

Do you have any codes? Does it smell like fuel under the oil cap?

I would tow it in. I wouldn't drive it in, personally.

[Hotflare]

Originally Posted by theweebabySeamus

Sounds a lot like an injector.

Do you have any codes? Does it smell like fuel under the oil cap?

I would tow it in, I wouldn't drive it in, personally.

No codes surprisingly. Ran the bm3 code reader, may run the bimmercode version too...

It does smell like E, but tbh it always smells like it due to the dilution over time. It's at the end of 1400 miles since the last change at 3500 on E (first time)

Cruises normally and idles ok (backfires 2 to 3 times on a neutral rev to 4k before idling normally again) but you're right on towing in

[Wanted_M]

Bad injector is my best guess, remove each plug and see which one is wet with fuel. These EU6 have a tendency to stick open when pushed above their design limitations with an aggressive tune.

[N1rve]

Originally Posted by Hotflare

Question, fellow gearheads...

My M3 has been recently running oddly , with a lack of power similar to a large boost leak on acceleration as well as white vapors from the exhaust that smell of fuel. Car currently has 64k, is on bm3 flex tune (91) running e50-e60 max. Also have the bend flex fuel kit with filter for the last 4k miles ....

Car sounds like a tractor with acceleration, too , so haven't been driving it outside of 5 miles total. Checked for leaks (none) and will take it to my local shop to inspect for boost leaks+change the oil.

Wondering if it could be the infamous stuck injector or a hidden boost leak somewhere, but Car throws 0 codes. Thought of datalogging but don't want to accidentally make things worse.

Advice? T.I.A.

I think you might have an intercooler leak. It may be leaking coolant into the engine and burning it which causes the "white vapor". Loss of coolant in the intercooler will result in hotter air which will lead to loss of performance.

[Hotflare]

Originally Posted by Wanted_M

Bad injector is my best guess, remove each plug and see which one is wet with fuel. These EU6 have a tendency to stick open when pushed above their design limitations with an aggressive tune.

Great call. Will do

[Hotflare]

Originally Posted by N1rve

I think you might have an intercooler leak. It may be leaking coolant into the engine and burning it which causes the "white vapor". Loss of coolant in the intercooler will result in hotter air which will lead to loss of performance.

I would agree so, but I'm running a wagner tmic lol...but it smells way more like fuel than the sweet smell of coolant sadly

[MINERALGREY_F80M3]

When I had an injector stick on my first F80 I immediately got mis-fire codes.

I'd suggest pulling the plugs and smelling for fuel / seeing if any are wet.

If that is the case, swap for a new injector and make sure to do at least 2 oil changes to flush out any fuel left inside. It took me 2 oil changes to confirm all fuel was out of the oil.

[Hotflare]

Originally Posted by MINERALGREY_F80M3

When I had an injector stick on my first F80 I immediately got mis-fire codes.

I'd suggest pulling the plugs and smelling for fuel / seeing if any are wet.

If that is the case, swap for a new injector and make sure to do at least 2 oil changes to flush out any fuel left inside. It took me 2 oil changes to confirm all fuel was out of the oil.

Interesting. And in the case I'm not throwing a CEL or codes....injectors?

[theweebabySeamus]

Originally Posted by Hotflare

Interesting. And in the case I'm not throwing a CEL or codes....injectors?

Pull the plugs like others have mentioned, don't guesstimate. The offending cylinder will be very obvious if you pull the plugs and it is an injector.

[Hotflare]

Originally Posted by theweebabySeamus

Pull the plugs like others have mentioned, don't guesstimate. The offending cylinder will be very obvious if you pull the plugs and it is an injector.

Will do. Just wild though, guess I should of driven the car more if it is. Took too much comfort in the bend filter

[theweebabySeamus]

Well if you decide to get rid of it, let me know

[Hotflare]

Originally Posted by theweebabySeamus

Well if you decide to get rid of it, let me know

Lol I can't. I stay in CA , nazi car Capitol of the US. This is my escape from our shit 91 lol

[theweebabySeamus]

Originally Posted by Hotflare

Lol I can't. I stay in CA , nazi car Capitol of the US. This is my escape from our shit 91 lol

Thats why I want it. Lol

[Hotflare]

Originally Posted by theweebabySeamus

Thats why I want it. Lol

Lol where at in cali are you?

[Wanted_M]

Originally Posted by Hotflare

Will do. Just wild though, guess I should of driven the car more if it is. Took too much comfort in the bend filter

Driving the car more won't resolve your issue, it's the tune fuel/loading that places the injectors above their design rating to meet the E% you're asking for from the tuner. Lower the loading or E% and that should help you stay below the threshold or upgrade to EU5's. IIRC, EU5's flow around 15-20% more than EU6's. Look for stuck injector threads on here, good luck bro and let us know what you find.

[Hotflare]

Originally Posted by Wanted_M

Driving the car more won't resolve your issue, it's the tune fuel/loading that places the injectors above their design rating to meet the E% you're asking for from the tuner. Lower the loading or E% and that should help you stay below the threshold or upgrade to EU5's. IIRC, EU5's flow around 15-20% more than EU6's. Look for stuck injector threads on here, good luck bro and let us know what you find.

Oh trust me I know. Sucks though, as much as I want to code in EU5s, Seamus above knows that we'd insta fail smog here, and it's too much of a hassle going back and forth. Smh I'll let you guys know though !
(Wish we had injector options like my old track ready evo x, had ID1300s and never had fueling issues on full E lol)