Misfire, Misfire, Misfire

[GuamX1]

I disabled the jb4 and drove my car today and still got the misfire and the following codes.

1. Aftercat 02 sensor trim control, bank 2 002C7F
2. 02 PreCat sensor system check, bank 1 002C2B
3. 02 Precat sensor system, bank 2 002C2C
4. Misfire Cylinder 6 0029D2
5. To misfire at low fuel level 0029D9
6. Misfire detection cylinder 3 in 2 firing order 0029CF
7. Misfire detection error summation 0029CC
8. AfterCat 02 sensor trim control bank 1 002C7E

on a previous scan it gave me misfire cylinder 6 and a low fuel pressure sensor code. I have replaced all the plugs all the coils and the Low Fuel Pressure Sensor. It seems to run better when first starts but get bad the longer it runs? I am not sure when fuel filter was last changed car has 66524 miles on it.

I also noticed that this morning when I was going to put fuel the gas cap could not be removed until after a while of trying. Not sure if this has something to do with the misfire.

The dealer would charge me an arm and a leg.

[BMW135pls]

Under what conditions is the misfire occurring? Idle? Normal driving? WOT?

[GuamX1]

Originally Posted by BMW135pls

Under what conditions is the misfire occurring? Idle? Normal driving? WOT?

Not much at idle when the car has just been started from cold but after it reaches operating temp it starts to misfire from idle all the way to WOT, Thanks

[GuamX1]

Got home early replaced the coils on cylinder no 2,3 and 6. When cold car seems to run fine but as it reaches normal operating temperature the misfire gets worst. Cleared the codes after i replaced coils. After driving a few miles scanned it again and got the following codes:

1. Aftercat 02 sensor trim control, bank 2 002C7F
2. 02 PreCat sensor system check, bank 1 002C2B
3. Misfire Cylinder 6 0029D2
8. AfterCat 02 sensor trim control bank 1 002C7E


Why is cylinder #6 always in the picture?

[all4bspinnin]

guam,

Cylinder 6 has a few different things going on...

first its in the back of the engine bay and see's a lot of heat.

2, and most importantly for your situation in my opinion... Cylinder 6 gets the dirtiest from carbon build up in my experience. My car would throw all of the codes youre seeing for cylinder 6 and cat. It never threw the fuel pump code though.

You need to have the walnut shell blasting (carbon cleaning) performed. That should help if not cure it completely. I would say to have these cars cleaned every 40k if not a bit less. Same with plugs and coils.

My cylinder 6 was definitely the nastiest one and im sure that's why it would misfire. After the carbon cleaning cylinder 6 misfires disappeared.

[GuamX1]

Originally Posted by all4bspinnin

guam,

Cylinder 6 has a few different things going on...

first its in the back of the engine bay and see's a lot of heat.

2, and most importantly for your situation in my opinion... Cylinder 6 gets the dirtiest from carbon build up in my experience. My car would throw all of the codes youre seeing for cylinder 6 and cat. It never threw the fuel pump code though.

You need to have the walnut shell blasting (carbon cleaning) performed. That should help if not cure it completely. I would say to have these cars cleaned every 40k if not a bit less. Same with plugs and coils.

My cylinder 6 was definitely the nastiest one and im sure that's why it would misfire. After the carbon cleaning cylinder 6 misfires disappeared.

Thank you i am also still running with the original HPFP. Why would this happen especially when at normal operating temperature? Thanks again

[GuamX1]

Switched the spark plug on cylinder #6 to #1 and #1 to #6. I must say the car ran so much better but still has that hiccup which you could barely feel. I was able to drop kids to school and almost was back home when the service engine light came on.

Yesterday just on my way to drop off kids to school and it already misfired and was very rough. Today you could feel the misfire but not as bad as yesterday. I have to conclude that swapping the plugs made a big difference.

Unfortunately I was not able to scan the codes because my IPhone ran out of battery. I'll do it later. Anyway I took some pictures of the plugs as I removed them. I also took pictures of the plugs I removed before the NGK these are for cylinder 1 and 6 only.

NGK Plug Cylinder #1 with less than 70 miles



NGK Plugs Cylinder #6 less than 70 miles



Bosch Plugs Cylinder #1 with about 2K miles



Bosh Plugs Cylinder #6 with about 2K miles

[all4bspinnin]

You need to have the carbon cleaning service done. Its almost a must with your mileage. It should cure a lot of this. Log you HPFP and make sure its getting the right consistent psi

[GuamX1]

Originally Posted by all4bspinnin

You need to have the carbon cleaning service done. Its almost a must with your mileage. It should cure a lot of this. Log you HPFP and make sure its getting the right consistent psi

I hope this is it, I called the dealer and they do not do the media blasting service. So I ordered my own media blasting kit from bavauto. I hope this will cure all these issues.

I still need to buy a compressor. Will a 33 gallon 5.2 SCFM compressor do the job?

If anyone is on Guam and needs cleaning let me know

[GuamX1]

scanned the car again today and got the following codes, what do they mean?

1. Aftercat 02 sensor trim control, bank 2 002C7F
2. 02 PreCat sensor system check, bank 1 002C2B
3. AfterCat 02 sensor trim control bank 1 002C7E

Thanks

[BMW135pls]

So should someone wait until they've had a carbon cleaning to replace their plugs/coils, or does it not matter?

I've heard that there are considerable risks when doing a carbon cleaning, as some debris can get caught in the cylinders and can cause the engine to eat itself.

[GuamX1]

Originally Posted by BMW135pls

So should someone wait until they've had a carbon cleaning to replace their plugs/coils, or does it not matter?

I've heard that there are considerable risks when doing a carbon cleaning, as some debris can get caught in the cylinders and can cause the engine to eat itself.

If I knew that this car needs this kind of maintenance I would have not bought one....anyway I'll keep this thread going when I get the media blasting done

[BMW135pls]

Originally Posted by Guam135i

If I knew that this car needs this kind of maintenance I would have not bought one....anyway I'll keep this thread going when I get the media blasting done

Well a catch can and a meth system is supposed to stop oil carbonization from happening in the first place. Then you should theoretically never have to do an intake cleaning again. The new M4 GTS will come with a meth injection system from factory.

[Dackelone]

Originally Posted by Guam135i

Switched the spark plug on cylinder #6 to #1 and #1 to #6. I must say the car ran so much better but still has that hiccup which you could barely feel. I was able to drop kids to school and almost was back home when the service engine light came on.

You've just answered whats wrong...

I would first use BMW spark plugs bought at a BMW dealer. I've said this so many times before(and seen people chase their tails) but using BMW spark plugs DOES make a difference. Not Bosch OEM plugs, but the BMW-Bosch plugs that the dealers sell.

Replace the plugs and see what happens.

I suspect you also have a problem with your HPFP and more importantly the low pressure switch near the HPFP on the rail. IF your car is a US spec car... this is covered under an extended warranty. But the sensor is NOT.

ALL the new direct injection cars suffer from carbon builtup. But I really think your problem is spark plug related. One way to tell - about your slight miss at idle... is to use a OBDII scan tool and LOOK at your idle speed. IF the idle decreases WHEN you feel the engine miss or stumble... THEN you have a primary ignition problem(spark plugs, coils, TDC sensor). IF you feel the miss but no idle speed change... then its probably an injector or carbon buildup issue.

Good Luck,
Dackel

PS: low pressure sensor in the 2nd photo bellow. It has a brass hex head.

[Dackelone]

Originally Posted by BMW135pls

Well a catch can and a meth system is supposed to stop oil carbonization from happening in the first place. Then you should theoretically never have to do an intake cleaning again. The new M4 GTS will come with a meth injection system from factory.

Not meth but WATER injection. Should be good for a ~100 Hp bump in power. I think the newer cars will still have carbon buildup problems though.

Dack

[GuamX1]

Originally Posted by BMW135pls

Well a catch can and a meth system is supposed to stop oil carbonization from happening in the first place. Then you should theoretically never have to do an intake cleaning again. The new M4 GTS will come with a meth injection system from factory.

I have a burger tuning catch can on my car. Not meth injection no place on Guam to buy the mixture.

[GuamX1]

Originally Posted by Dackelone

You've just answered whats wrong...

I would first use BMW spark plugs bought at a BMW dealer. I've said this so many times before(and seen people chase their tails) but using BMW spark plugs DOES make a difference. Not Bosch OEM plugs, but the BMW-Bosch plugs that the dealers sell.

Replace the plugs and see what happens.

I suspect you also have a problem with your HPFP and more importantly the low pressure switch near the HPFP on the rail. IF your car is a US spec car... this is covered under an extended warranty. But the sensor is NOT.

ALL the new direct injection cars suffer from carbon builtup. But I really think your problem is spark plug related. One way to tell - about your slight miss at idle... is to use a OBDII scan tool and LOOK at your idle speed. IF the idle decreases WHEN you feel the engine miss or stumble... THEN you have a primary ignition problem(spark plugs, coils, TDC sensor). IF you feel the miss but no idle speed change... then its probably an injector or carbon buildup issue.

Good Luck,
Dackel

PS: low pressure sensor in the 2nd photo bellow. It has a brass hex head.

Yes idle speed decreases when it stumbles and you can hear the noise from the DMFW. I am not using BMW OEM plugs I bought the bosch ones and NGK and bosch coils. I already replaced the Low Fuel pressure sensor. Yes it is a US Spec car so do you think I should go ahead and have the HPFP recall done regardless if it is the issue or not?

Great help thanks to both of you!

[Dackelone]

Originally Posted by Guam135i

Yes idle speed decreases when it stumbles and you can hear the noise from the DMFW. I am not using BMW OEM plugs I bought the bosch ones and NGK and bosch coils. I already replaced the Low Fuel pressure sensor. Yes it is a US Spec car so do you think I should go ahead and have the HPFP recall done regardless if it is the issue or not?

Great help thanks to both of you!

Yes, have the HPFP recall done. I would also change your spark plugs first to BMW dealer bought ones. Then see how the engine runs.

[MZWIE]

Dack:

Where did you find the PICS of the naked N54. Also why is the exhaust pointing in the opposite direction.

[BMW135pls]

Originally Posted by BMW135pls

So should someone wait until they've had a carbon cleaning to replace their plugs/coils, or does it not matter?

I've heard that there are considerable risks when doing a carbon cleaning, as some debris can get caught in the cylinders and can cause the engine to eat itself.

Bump for an answer? I'm planning on doing my plugs/coils soon, so I'd like to know if I should wait until after a cleaning or not.

[ShocknAwe]

Originally Posted by BMW135pls

Bump for an answer? I'm planning on doing my plugs/coils soon, so I'd like to know if I should wait until after a cleaning or not.

Doesn't matter. They close the valve, clean it, and then move to the next one. Any trace particles left behind after vacuuming it all out will get burned up during combustion.

[BMW135pls]

Originally Posted by ShocknAwe

Doesn't matter. They close the valve, clean it, and then move to the next one. Any trace particles left behind after vacuuming it all out will get burned up during combustion.

I meant more from the standpoint of would an engine that needs carbon cleaning foul my brand new ignition hardware?