[nukezero]

Hey guys

Just celebrating my first, full-on problem with the car. First Service Engine Soon light that stays on. Car still drives perfectly fine even after.

It happened at 99260 miles and right when I started the car this morning to go to work. The car was perfectly and has been perfectly fine for the 5 1/2 years before.

I wonder what it could be. Everything is all stock and factory original, except spark plugs, water pump, and thermostat. All of which were changed out as preventative maintenance.

I'll grab my OBD2 scanner tonight.

Does anyone know what is worse? SES light or those half-engine orange icons or those full-engine RED icons?

What's the difference between having those engine icons versus having the SES light? If you have the engine icons, would you also have SES light?

** EDIT: Got the error code: 29E0. What is it??

[hockeyplayer]

First things first make sure your gas cap is seated firmly. It can be something that simple.

[BashShah]

Let us know what codes you get.
Else its just guess work.

DN

[eforty6_m3]

Originally Posted by DarkNemesis

Let us know what codes you get.
Else its just guess work.

DN

^ This

It could be any number of things. Find out what codes you're throwing and then you'll be able to zero in. I had my SES light triggering on and off for weeks due to a crap wire on my DTML pump. But could also be a loose gas cap.

Keep us posted and hopefully it's something minor.

[nukezero]

I got the ERROR Code! It happened twice today. Both at low rpm. I'm assuming this happened during start-up when the car sits for a while.

Anyhow, the code is 29E0. That's the ONLY code.

What is this problem? Bad gas? Just filled up the gas tank at a new Shell gas station the other day.

Spark plugs were changed with OEM BMW about 6000 miles ago. Everything else all factory original and stock relating to the fuel/air engine components. Car drives like a champ still with the error.

temperature today was 73F

[nukezero]

Checking my Bentley service manual gave me more clues!

BMW FC 29E0 Definition - System Too Rich at Idle (Bank 1)

BMW FC 29E0 Definition - System Too Lean at Idle (Bank 1)


So it could be both lean or rich at idle.

[inrev`]

Mehhh...maybe check your chargepipe for cracks? im probably wrong though but who knows

[fravel]

When's the last time you changed your air filter?

I'd do that, and clean the MAF sensor.

[nukezero]

hrrm. It's been a while sense I changed air filter. Maybe 40k miles?

As for charge pipe cleaning and MAF cleaning, probably should do it . Hehe. I know my charge pipe is gunked with oil inside due to blow by.

Good suggestions. I'll get down to it this weekend.

I've reset the codes and restarted the car and rev'd it a little bit. So far codes are not back. The car probably needs to sit for more than a few hours.

The error log mileage seems to indicate that it occurred the first cold start in the morning, and then when I went to go home from work (8 hours later).

I'm also highly suspecting bad gas. The reason is because I had about a 1/8 of a tank and I filled up at a new gas station that I normally don't go to. Fuel then went down to 7/8 now and that is when the problem started, which correlates where the questionable fuel is now being used. Maybe they screwed up and put 87 octane in the 91 tank?

[shadow191]

335 shouldn't have a MAF, only the N/A motors do.

[dbworld4k]

Too rich means your air fuel ratio is off and the car was putting in too much fuel.

Nothing to do with your CP. Check your O2s or your spark plugs if they've never been done. Hopefully it's not leaky injectors dumping fuel while the car is sitting and when you start, it's detecting too much fuel and triggering that fault.

Edit: just saw your latest post. Triggering at morning start and then 8 hours later leads me to believe your injectors could possibly be leaking a very small amount of fuel. After periods of sitting, it's pooling in the spark plug chamber.

[fravel]

Originally Posted by shadow191

335 shouldn't have a MAF, only the N/A motors do.

Whoops, didn't realize OP was 335i.

Still, change your air filter(s).

[Austin 1439]

Id say take it somewhere professional to have each cylinder checked for misfires or injector issues. You get what you pay for so don't be cheap about fixing.

[nukezero]

Drove to work this morning and nothing happened. No code was thrown, even from a cold start. The 29E0 is baffling because according to the manual, it is either too lean or too rich at idle.

Why couldn't they be more specific? tell me lean or rich. and third, tell me which cylinder. How can all six cylinders be lean or rich at the same time?

[WilliamS]

Could be a bad o2 sensor, leaky injector, or worse a manifold leak.

[shawntech]

I vote injector

[BashShah]

When is the last time you had a walnut blast.
Could be early indication of carbon build up.

DN

[nukezero]

It's been 3 days.. the problem has NOT returned... I'm calling this one of those BMW gremlins. If its an exhaust gasket leak, or intake leak, it should have been easily reproducible.

I'm betting this is bad gas. I've been driving normally and slightly aggressively and nothing happens.