3Series

Does anyone know what could be wrong? I have a Check Engine light.

Background:
997.2 C2S
37,000 miles
All stock - ~25 track days on the car
Plugs and coils are original.

I was at the track,before the CEL went on, I checked my oil on the grid and no bars in the middle were lit, I figured this was bad but not that bad since The last bar wasn't blinking and the car wasn't telling me to add oil.

Anyways, I ran the session but only got in a couple of laps before the CEL threw, so I pitted after 10min or so.

I added some oil and shut the car down. I actually added a little too much so the oil was right at the overfill mark because it would change to be overfilled or just at the top. Again, I didn't think it was that big of deal.

On my second session, the CEL wasnt lit anymore, so I ran the session. Again after a couple laps the light went on so I pitted.

One of the crews at the track had a PIWIS computer, they read the codes, it said misfires on 1,2,4 (I think that's the left side). They didn't see anything else wrong. They cleared the codes and drained some oil for me.

On the third session, same deal again. I had the car read again and this time it showed some misfires on the other bank of cylinders. (3,5,6).

Anyway, I was able to drive home fine, 2.5 hours at a steady 75mph with no issues, just a CEL light on.

On track, when the CEL is thrown, I seemed to lose power and the car wouldn not goo faster than 105 in straights where I would hit 125+ Probably self protection from the computer.

Thoughts?

996AE

This is going to be good.

semicycler

Bank 1 is 1,2,3 driver's side exhausting out the passenger's side due to the exhaust crossover. Bank 2 is 4,5,6 passenger's side exhausting on the driver's side. So the misfire codes are across both banks moving around. The most common cause of misfires is coil packs. But since your misfires are moving it could be something else. Perhaps the crank position sensor going bad?

Too early to say it's oil related. Check sooting on the tailpipes, should be even. Pull the codes again and post the actual code numbers too.

3Series

Tailpipes are black as usual, they look normal to me. I don't have a code reader but the tech didn't see anything out of the ordinary in the codes, just the misfires. He spent about 10min (prob 5min of that waiting for the computer to boot up, lol).

Anyway, just seeing what others think. Perhaps AOS, MAF, lifter solenoids coils that are no longer good. I'm starting to think it's not the coils since whole banks were mis-firing.

I just ordered new plugs and coils, they are overdue anyway.

docdrs

Could be your hpfp starting to go since it seems to be a generalized issue but thats just my wag

Wayne Smith

HPFP problems seem to be based pin the 09s. It's a good idea of you have an 09.

docdrs

HPFP can really affect any DI year not just 09's. I know as mine is an 11 and had it go. FYI

myw

Likely coil packs cracked.... either way since your car appears to be going on limp mode , id take it to an indie / dealer to confirm

Wayne Smith

Any part can go ... you're right. To be accurate I should have said that the factory replacement program centered around the 2009 year.

3Series

I should offer up a prize for the correct Internet Mechanic diagnosis...

So far I have:
1.) HPFP
2.) Coil Packs

As the leading contenders....LOL

My indy is at Sebring this week with his whole crew so I won't be able to have a mechanic look at the car until next week. Hopefully the coils i ordered come in this week and I can replace this weekend.

docdrs

How much fuel was in your tank?

3Series

Pretty much a full tank. I filled up before heading to the track from my hotel (~5miles).

We did check the fuel cap to make sure it was tight....