330xi rough idle/misfire codes

Yay, new symptoms. :/

Went to drop off a movie today, left the car idle for 30 seconds. Got back in, drove off, and had a constant misfire for three stoplights, at idle and acceleration. Pulled into a gas station, let it sit for a minute, started it up, and the miss was gone, but obviously the erratic idle was still present.

Stopped yet again to scan the codes, here's what I got this time:
P1342
P1348
P1345
P1346
P1351
P1352
P0300

Stop driving it. Seriously. Fix the problem before more sh!t breaks.

Also:

Originally Posted by Silversixspeed

Stopped yet again to scan the codes, here's what I got this time:
P1342 - Cylinder 1 misfire at start
P1348 - Cylinder 4 misfire at start
P1345 - Cylinder 2 misfire with fuel cutoff
P1346 - Cylinder 3 misfire at start
P1351 - Cylinder 5 misfire with fuel cutoff
P1352 - Cylinder 6 misfire at start
P0300 - Random multiple misfires

My theory now is that this is not an intake or idle valve issue as those manifest as a lean condition. I believe you have a fuel delivery problem. Check fuel pump, fuel filter, and run a bottle of techron through a tank of gas.

Chalk up another bad DISA valve, pulled it out last night and it nearly fell apart in my hand. Pulled the metal pin out with ease, glad it didn't fall out in the intake! The seal was definitely causing a vacuum leak as well, I'm thinking this was original, and at almost 120,000 miles, it sounds like it was due.
Put a new one in (as well as cleaned the MAF, that thing was nasty!) and it runs like a dream now.

Thanks again guys!

Interesting you never got a lean condition code...

got a question for either SamDoe1 or Kubica, what is the DISA Valve and where is it on a 325xi?

Originally Posted by tomoyer

got a question for either SamDoe1 or Kubica, what is the DISA Valve and where is it on a 325xi?

DISA is the intake actuator valve. It alters the length of the intake runner for either low end torque or high end horsepower. If you notice a "hump" in the powerband at around 4k rpm, that's the changeover the DISA makes.

It's the rectangular black box mounted to the top driver's side of the intake manifold. Has a little solenoid on it too, can't miss it.

Thanks SamDoe1, thought that was the DISA. A bad DISA have effect on random idle speed at times? Not throwing any misfire codes or anything like that, actually throwing O2 sensor control limit codes for cyl #1-3 and #4-6 O2 sensor adaptation limit codes for #1-3 and #4-6. I just replaced the pre-cat O2 sensors and that took away the random misfire codes but the 4 codes have reappeared..........thinking I also need to replace the post-cat O2 sensors as well. What's your take on it? You can chime in as well Kubica.

The O2 sensor codes should tell you which sensor is failing or has failed (sensor 1 or 2). I'm not sure that the DISA would have an effect on idle speed or not but it's easy enough to check its operation.

Have you checked/cleaned your idle valve?

Idle Control Valve was checked and cleaned at same time Throttle Body was Cleaned, when I replaced Oil Separator Valve and its 4 hoses, though not saying it isn't bad. Total of 4 sensors on the XIs, 2 pre-cat and 2 post-cat. Definitely the pre-cat ones were bad, and after replacing them the random misfires of all cylinders went away (been a week now since replacing and clearing codes). However, after 3 days, the codes I mentioned before came back, so: 1) I'm thinking the post-cat O2 Sensors need to be replaced, 2) the DISA should at least be checked. The pre-cat O2 Sensors if not working correctly will lean the fuel/air mixture out and can cause random misfires.

Originally Posted by tomoyer

Idle Control Valve was checked and cleaned at same time Throttle Body was Cleaned, when I replaced Oil Separator Valve and its 4 hoses, though not saying it isn't bad. Total of 4 sensors on the XIs, 2 pre-cat and 2 post-cat. Definitely the pre-cat ones were bad, and after replacing them the random misfires of all cylinders went away (been a week now since replacing and clearing codes). However, after 3 days, the codes I mentioned before came back, so: 1) I'm thinking the post-cat O2 Sensors need to be replaced, 2) the DISA should at least be checked. The pre-cat O2 Sensors if not working correctly will lean the fuel/air mixture out and can cause random misfires.

What are the codes? Agreed the pre-cats were bad, but I'm not sure the post cats don't go bad that often.

Reason I ask is that the code will often read, for example, "O2 sensor adaptation limit, bank 1 sensor 2" or something like that.

SamDoe1, Codes are: CA - O2 Sensor Control Limit Cylinders #1-3 (bank 1 if you will), CB - O2 Sensor Control Limit Cylinders #4-6 (bank 2 if you will), E3 - O2 Sensor Adaptation Limit Cylinders #1-3 (again, bank 1 if you will) and E4 - O2 Sensor Adaptation Limit Cylinders #4-6 (again, bank 2 if you will). You may not be familiar with these codes from my code reader. Am thinking that since the fuel/air mixture was lean and the random misfires because of the bad pre-cat O2 Sensors making it lean, that the post-cat O2 sensors could have gone bad/out of limit because of too much heat from the lean condition, and even though the lean fuel/air mixture was corrected with the new pre-O2 Sensors, the post-cat O2 Sensors are now out of the adaptation range. The reason I asked about the DISA was because I hear it once in awhile and figure it needs to be checked and either repaired or replaced.

It may be an issue with the SAP. Check that the pump runs, check valve opens, hoses aren't cracked, and the valve opens under vacuum. Bavauto has a nice writeup detailing the system and how to troubleshoot.

Thanks Kubica for that info, I checked that blog tech link at bav auto, but I'm ruling the Secondary Air Pump and its related parts out at this time BECAUSE I DO NOT have any SAP Codes being thrown, only have the 4 O2 Sensor Codes listed above AND the post-cst O2 Sensors are the original ones with 128,000 miles on them. The SAP really only runs for a short period of time (maybe up to 5 minutes or so) when the engine is started up cold and is used to inject more air into the exhaust for more complete burning of the hydro-carbons coming out of the exhaust system and the SAP has its own set of codes if not working/working correctly. I will be checking the vacuum hoses related to the SAP just to make sure none are cracked, though.
BTW, bav auto also has a nice tech blog listing quite a few of the common fault codes which can be a good reference.

I'm leaning very much towards the DISA, as I can clear those 4 codes, drive for several days and then the codes reappear again (usually after a long hard high speed run going down to normal speed of 40 mph. As I said before, my DISA has been making some noise, and I think that it can affect the O2 sensor circuits if not operating correctly.
Kubica, everything on the SAP circuit is working ok, but extra input is always welcome.
Once I order a new DISA (so it is on hand when I remove and inspect the old one) I will report back to this thread. There is another new thread; Peake E36, E46 Code 19 that has attached 2 video clips of checking and replacing the DISA on an E46.