[jhawk]

Hello: I have a '06 330xi with 54k miles on it. Today during my lunch break I filled up the tank with 89 octane, 10% ethanol gas (live in the midwest where ethanol is everywhere). I've never had problems with gas from this station before, or with any ethanol gas.

Anyway, when I started the car to go home this evening, it struggled to start and the idle was a bit rough. Once the engine warmed up, the idle got a lot worse as did the acceleration. I would press the gas, but the car wouldn't accelerate, but would bog down a bit. At that point, the "check engine soon" light came on.

I got home, let the car sit for a bit, and restarted it. The car was still hard to start and the idle was lumpy: jumped from 500 to 1000 RPM's while idleing. Any ideas what the heck is going on?? Thanks in advance.

[darkphantom]

while it may not attribute to much, filling up a gas tank adds weight to your vehicle...but as far as the rough idle, it may be due to poor fuel? not sure. have you tried any 91/93 oct?

However the check engine light (CEL) is a reduced power mode and you would need to restart the vehicle. If you have the extended warranty, take it to the stealer, else figure out what code was stored with a BT scanner tool

[AMZ]

sounds similar to what i used to get with my e46 and my friend's e60 when the air mass flow sensor needed cleaning/changing. When is the last time you had an oil change? What is your oil level now? This affects your air mass flow sensor. Not at all sure though if this is the same thing.

Do u reckon it is being caused by poor quality petrol?

[jhawk]

Thanks for the suggestions. I changed my oil about three weeks ago. No problems with the car until now.

How can you tell if you have bad gas? I filled the tank full, so I can't add anymore. I suppose I can drain the tank and refill...what a PITA that'd be! I have an aftermarket extended warrantee and will take the car to the shop tomorrow.

I've owned this car since last summer and like it a lot. I knew I was taking a gamble with a high mileage BMW and I think I've lost my bet: Since I bought the car I've had the steering column replaced, a seperate sensor associated with the steering column replaced, a low oil pressure problem that resolved itself, and now this. This has been the most unreliable car I've had since college. I had to pay for the sensor myself. Depending on how bad\expensive this problem is, I'll probably be trading this car in. I'm not condemning all BMW's....just mine!

[vadim]

Originally Posted by AMZ

sounds similar to what i used to get with my e46 and my friend's e60 when the air mass flow sensor needed cleaning/changing. When is the last time you had an oil change? What is your oil level now? This affects your air mass flow sensor. Not at all sure though if this is the same thing.

Do u reckon it is being caused by poor quality petrol?

Not unless someone deliberately diluted it with diesel or put water in it.

It could be anything - failed coil (has happened to my previous car), failed spark plug, MAF sensor (as suggested above), O2 sensor. Take it to the dealer - they will read the code thrown and give you an answer w/o any guessing.

Best,

[1013mm]

bad gas? I never got that the car actually feels better when it gets gas..

[jhawk]

I don't know if anyone is still reading this thread, but here's what the shop found out about my car and its problem. This is an independent shop that specializes in foreign cars as the closest dealership is 5 hours away.

This is a quote from the ticket:

"Scanned for codes, PO174 system too lean. Checked for vacuum leaks and found none. Short term fuel trims (Bank One 3.1%) Short term fuel trims (Bank Two 28.7%) Fuel trims on Bank One go to +29%. Smoked intake to check for vacuum leaks and found none. Took a couple of fuel samples, the first sample did appear to seperate a little (water in gas), the second sample appeared OK. Plugged throttle body and turned over a few times to try and clear any blockage in oil seperator. Cleared codes and test drove. Bank Two Fuel trims started going down afer driving for awhile. Fuel trims are now normal + or - 3%. (May have had some bad gas or the oil seperator is starting to plug). Test drove car again in AM and it starts and runs fine. Would recommend customer drive this tank of gas down and fill again."

The car still has mild lumpy idle and flutters a bit under acceleration. Check engine light came back on as I was driving out of the shops parking lot. They still recommend driving the tank empty to see if the problems go away. If not, they think it's the oil seperater...appx. $800.00 repair charge.

Can anybody decipher and explain what "Fuel trim levels" are? Thanks.

[HermesRider]

Originally Posted by jhawk

Can anybody decipher and explain what "Fuel trim levels" are? Thanks.

Although it's from a mustang forum (don't kill me guys), this guy knows what he's talking about:
http://forums.mightymustangs.net/ind...howtopic=18816

When you were gassing up, was there a big petrol truck dumping gas into the station by chance?

[Oulixes]

Originally Posted by jhawk

Hello: I have a '06 330xi with 54k miles on it. Today during my lunch break I filled up the tank with 89 octane, 10% ethanol gas (live in the midwest where ethanol is everywhere). I've never had problems with gas from this station before, or with any ethanol gas.

Anyway, when I started the car to go home this evening, it struggled to start and the idle was a bit rough. Once the engine warmed up, the idle got a lot worse as did the acceleration. I would press the gas, but the car wouldn't accelerate, but would bog down a bit. At that point, the "check engine soon" light came on.

I got home, let the car sit for a bit, and restarted it. The car was still hard to start and the idle was lumpy: jumped from 500 to 1000 RPM's while idleing. Any ideas what the heck is going on?? Thanks in advance.

In my 330xi I use 91 octane gas, but except for that our cars should be comparable. I've never had a problem similar to yours, but several people on the forum reported problems caused by poor quality of fuel. Try the search.

[galahad05]

Originally Posted by HermesRider

Although it's from a mustang forum (don't kill me guys), this guy knows what he's talking about:
http://forums.mightymustangs.net/ind...howtopic=18816

When you were gassing up, was there a big petrol truck dumping gas into the station by chance?

Nice link: very informative!

[jhawk]

Thanks for the replys. I don't remember if there was a tanker truck restocking the gas stations fuel supply while I was there. The mechanic who worked on my car asked the same thing for the same reasons.

I tried to siphon gas out of the tank tonight, but GEESH, the BMW filler tube must be 10 feet long and twisted as hell! I couldn't reach the gas in the tank (3\4 full) with 3 feet of hose fully stuffed down the fuel filler tube! So, I'll just have to drive around a lot and burn off the gas to see if that's the problem.

[HermesRider]

Yeah, burn off the gas, eh!

[Oulixes]

Originally Posted by HermesRider

Although it's from a mustang forum (don't kill me guys), this guy knows what he's talking about:
http://forums.mightymustangs.net/ind...howtopic=18816

When you were gassing up, was there a big petrol truck dumping gas into the station by chance?

As Galahad05 says your Mustang link is very nice - thanks.

[pford]

this is exactly what my car does...hard to start unless warm....idle goes up and down in traffic, parked, etc...always happens...and the idle generally is rough and shakes car with ease...

it goes into the dealer next week for whatever this is..

my old 1991 325i idles like a champ..

[kingka]

Originally Posted by pford

this is exactly what my car does...hard to start unless warm....idle goes up and down in traffic, parked, etc...always happens...and the idle generally is rough and shakes car with ease...

it goes into the dealer next week for whatever this is..

my old 1991 325i idles like a champ..

take it to dealer! you have 1 year left no?

[GregL]

Originally Posted by Oulixes

In my 330xi I use 91 octane gas, but except for that our cars should be comparable. I've never had a problem similar to yours, but several people on the forum reported problems caused by poor quality of fuel. Try the search.

+1

In addition, our (330i/xi) manual and the inside of the fuel filler door very clearly state that minimum 91 is to be used, unlike the 328's which have more liberal requirements.

[rotaryboy]

^ +1 right why are you using 89? ...and the one time I used 10% ethanol in my TL it ran like crap. Never again. Dump some Vpower or BP in next fill up.

[bulldog_yyc]

dude, treat your girl right and give her what she deserves.. which is at least 91, 94 if youre feeling hot LOL