Just bought and already have issues.

[jimmybond]

So I was gunning it ahead of a truck this afternoon and shifted a little later than I should have. Anyway the "SERVICE ENGINE SOON" light flipped on and the motor started idling rough. Anyway I pulled into a parking lot, opened the hood to see what I could see (which was nothing) and then shut the engine off. When I restarted, the check engine light went off and the rough idling ceased. Since I've bought the car I've noticed that when its in automatic mode (Have the SMG transmission) it frequently stutters when in low RPMs and accelerating, and it occasionally does this in manual mode (1st thru 3rd).

My buddy (who has an 03 3 series) says that his car was acting the same way and finally died...the issue was the camshaft position sensor. We're going to hook the diagnostic tool up to it tomorrow...

Anyone had this issue, or one similar? Love to hear some advice...thanks!

[jimmybond]

Forgot to add, while my buddy was driving it he accelerated it pretty quick (in auto mode) and got the check engine light to come on again. Same thing, shut off & restart cleared it. Also...I did fill it with plus yesterday. Does the octane rating REALLY factor that much into it???

[gtMc]

Originally Posted by jimmybond

Also...I did fill it with plus yesterday. Does the octane rating REALLY factor that much into it???

I'm not the most tech knowledgable of guys on the forum here (i might just be the first one up with a cup of coffee checking the forum). BUT I will say after 10 years of BMW ownership experience - I def say to be sure to put the correct type of gas in your car. if it calls for 91, get it 91 or better.

If the car is stuttering and you put 89 in it... this would be the easiest thing worth trying to correct first.

with that, I doubt 89 octane Gas would trigger a 'Service Engince Soon" light....

[RobMCoupe]

The symptom might be software related. There was issue when Z4 SMG on initial release. I don't recall if this was fixed with new software.

[jimmybond]

Originally Posted by RobMCoupe

The symptom might be software related. There was issue when Z4 SMG on initial release. I don't recall if this was fixed with new software.

I went into Kuni BMW (before the incident) and asked if there was anything i need to know about the SMG. The service guys said no (2 of them)...it was a good tranny, etc. He took the key and put it in there little key reader thing and was able to pull up service records, etc. He said that there wasn't anything required except the Inspection 1 in 6000 miles...

And yes, I'll be putting premium in from now on!

So I'll see if this sensor thing fixes it and let you all know.

[thekurgan]

I'd run some techron through the fuel tank, maybe 2 bottles back to back, only because it doesn't appear the car was driven much, and maybe short distances. If that doesn't help, some auto parts stores can see if there is a code stored. Many of us have a reader with the code descriptions to help you out. You may also want to change the plugs, air filter, routine stuff before it gets more expensive.

[jimmybond]

So we plugged in the code reader and it gave a yellow p0303...cylinder 3 misfire. Checked the coils, wires & spark plug & all were ok. Went ahead and swapped the sensor just to see if that was the problem. Still had the sputters but couldnt get the CEL to come on. I put tue old sensor back in and drove back home (about 35 miles). Car seemed to sputter less at the low rpms & rapid acceleration. Shut ot off, plugged the code reader in. Whereas before we couldnt clear the fault, after the drive home the code cleared. Just got done speeding it around the block. Minor sputter, but no CEL or a code (had the reader plugged in during the

Starting to think this has been caused by incorrect octane/maybe some fuel sediment from sitting so long?? Going to refill with premium and see whats up & do the techron deal described above. (Thanks btw).

[thekurgan]

Originally Posted by jimmybond

So we plugged in the code reader and it gave a yellow p0303...cylinder 3 misfire. Checked the coils, wires & spark plug & all were ok. Went ahead and swapped the sensor just to see if that was the problem. Still had the sputters but couldnt get the CEL to come on. I put tue old sensor back in and drove back home (about 35 miles). Car seemed to sputter less at the low rpms & rapid acceleration. Shut ot off, plugged the code reader in. Whereas before we couldnt clear the fault, after the drive home the code cleared. Just got done speeding it around the block. Minor sputter, but no CEL or a code (had the reader plugged in during the

Starting to think this has been caused by incorrect octane/maybe some fuel sediment from sitting so long?? Going to refill with premium and see whats up & do the techron deal described above. (Thanks btw).

If it sputters while it's running, remove the coil in cyl 3 and if the idle remains the same, rough, then that coil could be the fault. You can also shut the engine down, swap coil 3 with another, and see if the reader throws a code at the swapped cylinder. I think bad gas could be the issue, techron concentrate is worth $20 to spend to clean up anything fuel-related you suspect.

[pokeybritches]

How many miles are on the car? I'd change out the plugs, and try what thekurgan said with swapping the cylinder 3 coil with another and pulling the code. In my experience, a misfire will set off a hard light. A one-time deal is usually the result of a spark plug, but a continual misfire is due to a bad coil (although the reverse can be true as well... it's just not as common).

I've had poor gas in my 3.0i, and it didn't sputter. Instead it was like hitting the brake instead of the gas, I guess because the fuel filter had clogged. I ran a few bottles of cleaner through and the symptoms disappeared. It's been 40k miles and no issues. Try the cleaner, spark plugs, and coil.

[phoenixbmwlife]

I'm no expert but my sister's 3 series did the same thing a few months back. The computer also said it was a misfire in one of the cylinders. In her car the 3 series coils are known to go after a certain mileage 1 by 1. She changed the one that was misfiring and 2 weeks later it did it again. When put up on the computer a different cylinder misfired. She changed that coil and then a few days later another misfired. After the second one it was obvious all the coils are going one by one and need to be replaced. I told her just change all of them one time cause you could get caught 100miles away and one goes but she's waiting for them to go then fix cause its so damn expensive.

Anyway long story short you may have a similar problem and I hope this experience doesn't take away from the fact that you have one of the best handling cars. It is honestly the best handling car I have driven and most fun and i plan on keeping it for the long run. Good Luck to ya!

[jimmybond]

So bought a bottle of Techron and filled it with premium. Had only one sputter since, and I've been TRYING to make it do it again. No codes on the reader. The dealer I bought it from is going to run an "in depth" diagnostic check on Monday (with a fancier code reader I guess). But I am really convinced that there was like some sediment in the fuel system somewhere (from sitting so long) that the 89 fuel wouldn't burn off. Weird sh** but makes sense to me.

To answer porkeybritches: it's an 03 with 19k miles.

K3N R3D: No this hasn't detracted from my love for the car....I'm just an idiot who was trying to save a couple of bucks in gas! We'll find out Monday if I'm right!

Thanks to everyone for your insights.

[chickdr]

I am betting it will be coil related when all is said and done. You can't tell a coil is bad from its appearance. I would budget and replace your coils as you can(or at least #3).