Dealer says I need a new cylinder head...thoughts?

Background:
Bought car at 33k.
No problems until 36k. Problem occurred where idle was a little rough and acceleration from stop felt like it was 'kicking' until over 1k RPM. SES light comes on eventually. Brought to dealer. They kept it for 4 weeks, could NOT figure it out, PUMA case opened. After 4 weeks they gave it back saying it was fixed after 'significant diagnostics'. They gave no diagnosis but it was fine. I prodded further through phone calls but no official fix provided. The car ran great for 3.5 months.

March 2012: Issue from before re-occurs. SES light occurs, and same symptoms (rough idle, kicking randomly, kicking at acceleration whether in 1st or 2nd gear from a stop). Brought to dealer. They mentioned they would look at it immediately and they did. They've had it for a week, tried 'replacing a few parts'. I asked them to look at the MAF sensor, no dice unless they just ignored my suggestion.

Today get a call from my SA, they want to replace the cylinder head. They asked me to call back but I imagine it was just to explain and get permission. Anything seem off here to anyone else? This is a big fix that I am certainly worried about at 40k miles......

Ask them why the head needs to be replced. Does it have low compression in a cylinder?

Under warranty still. Maybe good to get it fixed now.

Hope that is core problem and all your troubles are resolved before factory warranty ends. Which dealer in Mass r u using for work?

F that tell them to give you ANOTHER engine its the 3rd time, fight them!!!

You are not the first person to post up about replacement cylinder heads. I'd love to know what BMW's reason is for why the head needs to be replaced.

They replaced my cylinder head due to carbon buildup. The engine was running just fine except I was getting a yellow SES light. Even after changing the cylinder head and EGR valve the SES came back. They ended up replacing the ECU which corrected the SES light issue. (ECU kicking false codes for replaced parts)

Originally Posted by Snipe656

You are not the first person to post up about replacement cylinder heads. I'd love to know what BMW's reason is for why the head needs to be replaced.

It sounds like they're just throwing parts at the problem. As Brian's experience showed the ECU was the cause of the SES indicator. If intake clogging was bad enough to warrant head/manifold replacement you can bet there'd be drivability issues as well.

Originally Posted by d geek

It sounds like they're just throwing parts at the problem. As Brian's experience showed the ECU was the cause of the SES indicator. If intake clogging was bad enough to warrant head/manifold replacement you can bet there'd be drivability issues as well.

Yes, it does sound like just throwing parts at a problem(which seems more typical than not on these cars). But I am just curious if each person who had their cylinder head replaced was given the same basic reason as to why.

Originally Posted by BrianNC81

They replaced my cylinder head due to carbon buildup. The engine was running just fine except I was getting a yellow SES light. Even after changing the cylinder head and EGR valve the SES came back. They ended up replacing the ECU which corrected the SES light issue. (ECU kicking false codes for replaced parts)

This is the same reason I was given. Excessive carbon buildup. Honestly the SES light in my case isn't false, there are drive-ability issues. Hopefully that won't be the case after the replacement but we will see. I will report back once it is completed.

Originally Posted by bimmerdiesel

Hope that is core problem and all your troubles are resolved before factory warranty ends. Which dealer in Mass r u using for work?

PM'd.

Curious to know about your driving habits. City, hwy, with traffic or faster?

Originally Posted by BMWTurboDzl

Curious to know about your driving habits. City, hwy, with traffic or faster?

70% highway, 30% city. Usually about 80 mph on highway at cruising speeds. I definitely don't track or ride the car hard really.

I have a "rough" idle as well. 23k miles on my 2010 d. Every once in a while, I get a hesitation after it sits for a few days and I start moving (in 2nd gear,) reproduce-able on a certain road and conditions. That is rare, but the rough at idle is not (for instance when slowing to a light and the engine is idle.)

I drive about 50% suburban, 50% highway. My 50% suburban contains lights where I have to idle for minutes...

Originally Posted by SpeedyD

70% highway, 30% city. Usually about 80 mph on highway at cruising speeds. I definitely don't track or ride the car hard really.

Makes me wonder about fuel quality ...cetane primarily

Sent from my MB525 using Bimmer App

Makes me wonder if there are some underlying EGR issues.

Originally Posted by BMWTurboDzl

Makes me wonder about fuel quality ...cetane primarily

Sent from my MB525 using Bimmer App

I only use 'premium' stations for diesel (name brands)

Originally Posted by Snipe656

Makes me wonder if there are some underlying EGR issues.

I can agree with this though...

Originally Posted by SpeedyD

I can agree with this though...

I only wonder on it because I have had EGR issues on my truck and it "plugged" up the intake tract and I am sure did a fair amount of carbon in the heads too. The descriptions I am reading here about the BMW cylinder head replacement needs just really reminds me of the same thing I was experiencing.

Carbon build up in the heads though is one of my fears with any direct injection engine. Not like any additive is going to address that after the fact since fuel should not be seeing the back side of the valves. This is why I try to run what I think are quality fuels.

They mean carbon inside the cylinder no?

Originally Posted by BMWTurboDzl

They mean carbon inside the cylinder no?

If they are replacing the entire head then I assume they mean carbon inside the cylinder head itself. Since they probably feel only way to remove is via taking the head apart? Although I bet a back purge could get most if not all out.

Scan of what was done with mine (used OCR to convert to text):

CUSTOMER CAME TO PICK UP CAR AND SES LIGHT WAS BACK ON . CAR
DID NOT LEAVE THE DEALER SHIP.
SHORT TESTED CAR AND FOUND FAULTS 4583 AND 4585 NOX SENSORS
AFTER CAT AND BEFORE CAT.NO TESTPLAN AVALIBLE FOR FAULTS
FAULTS DUE TO PROGRAMMING FROM LAST REPAIR AS PER PUMA.
PUMA SAID LTO REPLACE THE NOX SENSORS.REPLACED BOTH BEFORE
CAT AND AFTER CAT NOX SENSOR. CLEARED FAULTS AND TEST DROVE
PUMA CASE # 49531330
AFTER 30 MILES THE CHECK ENGINE LIGHT CANE BACK ON FOR FAULT
4AF5 ZERO QUANITY ADAPTION INJECTOR # 3.TESTPLAN SAID TO
REPLACED CYLINDER 3 INJECTOR.
SUPPLEMENTED TC CASE AND REPLACEMENT OF INJECTOR #3 WAS
AUTHORIZED. REPLACED CYL #3 FUEL INJECTOR, CALIBRATED TO DDE
AND PERFORMED FUEL SYSTEM BLEED TEST PLAN. CLEARED FAULT
MEMORY AND PERFORMED EXTENDED TEST DRIVE.
LIGHT CAME BACK ON AFTER TEST DRIVE FOR 4C04 EXHAUST GAS
TEMP FAULT AND SMOOTH RUNNING FAULTS CYLINDER 3,5,6,1
AS PER PUMA REMOVED INTAKE TO CHECK FOR CARBON AND CARBON
WAS FOUND IN INTAKE, VALVE COVER,EGR,THROTTLE VALVE AND
CYLINDER HEAD.
AS PER PUMA REPLACED CYLINDER HEAD. INTAKE,VALVE COVER,EGR
AND THROTTLE VALVE.PERFORMED RETRO FIT IN ISTA FOR NEW
EGR VALVE AND CODED COMPLETE CAR.

- -QTY- - -FP-NUMBER DESCRIPTION UNIT PRICE-

1 13-62-8-511-666 SENSOR FOR NOX WARRANTY

1 13-62-8-511-665 SENSOR FOR NOX WARRANTY

1 13-53-7-808-094 RMFD INJECTOR WARRANTY

1 11-12-7-806-061 CYLINDER HEAD WARRANTY

1 11-12-O-421-276 GASKET SET CYLINDER WARRANTY

1 11-12-7-798-532 SET BOLT CYLINDER H WARRANTY

1 11-12-7-809.860 CYLINDER HEAD COVER WARRANTY

1 11-61-7-823-073 INTAKE MANIFOLD WIT WARRANTY

1 11-71.8.517-217 EGR-VALVE WARRANTY

1 13-54-7-792-098 O-RING WARRANTY

1 11-71-7-804-384 THROTTLE WARRANTY

1 11-12-7-801-699 CYLINDER HEAD GASKE WARRANTY

2 07-11-9-963.151 GASKET RING WARRANTY

1 64-55-7-793-608 RIBBED V-BELT WARRANTY

1 82-14-1-467-704 ANTIFREEZE WARRANTY

Last part of that says they retrofitted a new EGR on there.

I am beginning to hate diesels with EGRs.

Originally Posted by BrianNC81

Scan of what was done with mine (used OCR to convert to text):

CUSTOMER CAME TO PICK UP CAR AND SES LIGHT WAS BACK ON . CAR
DID NOT LEAVE THE DEALER SHIP.
SHORT TESTED CAR AND FOUND FAULTS 4583 AND 4585 NOX SENSORS
AFTER CAT AND BEFORE CAT.NO TESTPLAN AVALIBLE FOR FAULTS
FAULTS DUE TO PROGRAMMING FROM LAST REPAIR AS PER PUMA.
PUMA SAID LTO REPLACE THE NOX SENSORS.REPLACED BOTH BEFORE
CAT AND AFTER CAT NOX SENSOR. CLEARED FAULTS AND TEST DROVE
PUMA CASE # 49531330
AFTER 30 MILES THE CHECK ENGINE LIGHT CANE BACK ON FOR FAULT
4AF5 ZERO QUANITY ADAPTION INJECTOR # 3.TESTPLAN SAID TO
REPLACED CYLINDER 3 INJECTOR.
SUPPLEMENTED TC CASE AND REPLACEMENT OF INJECTOR #3 WAS
AUTHORIZED. REPLACED CYL #3 FUEL INJECTOR, CALIBRATED TO DDE
AND PERFORMED FUEL SYSTEM BLEED TEST PLAN. CLEARED FAULT
MEMORY AND PERFORMED EXTENDED TEST DRIVE.
LIGHT CAME BACK ON AFTER TEST DRIVE FOR 4C04 EXHAUST GAS
TEMP FAULT AND SMOOTH RUNNING FAULTS CYLINDER 3,5,6,1
AS PER PUMA REMOVED INTAKE TO CHECK FOR CARBON AND CARBON
WAS FOUND IN INTAKE, VALVE COVER,EGR,THROTTLE VALVE AND
CYLINDER HEAD.
AS PER PUMA REPLACED CYLINDER HEAD. INTAKE,VALVE COVER,EGR
AND THROTTLE VALVE.PERFORMED RETRO FIT IN ISTA FOR NEW
EGR VALVE AND CODED COMPLETE CAR.

- -QTY- - -FP-NUMBER DESCRIPTION UNIT PRICE-

1 13-62-8-511-666 SENSOR FOR NOX WARRANTY

1 13-62-8-511-665 SENSOR FOR NOX WARRANTY

1 13-53-7-808-094 RMFD INJECTOR WARRANTY

1 11-12-7-806-061 CYLINDER HEAD WARRANTY

1 11-12-O-421-276 GASKET SET CYLINDER WARRANTY

1 11-12-7-798-532 SET BOLT CYLINDER H WARRANTY

1 11-12-7-809.860 CYLINDER HEAD COVER WARRANTY

1 11-61-7-823-073 INTAKE MANIFOLD WIT WARRANTY

1 11-71.8.517-217 EGR-VALVE WARRANTY

1 13-54-7-792-098 O-RING WARRANTY

1 11-71-7-804-384 THROTTLE WARRANTY

1 11-12-7-801-699 CYLINDER HEAD GASKE WARRANTY

2 07-11-9-963.151 GASKET RING WARRANTY

1 64-55-7-793-608 RIBBED V-BELT WARRANTY

1 82-14-1-467-704 ANTIFREEZE WARRANTY

Very interesting, this seems similar to what I am going to receive. When I get the car back I will post my information also.

Originally Posted by Snipe656

If they are replacing the entire head then I assume they mean carbon inside the cylinder head itself. Since they probably feel only way to remove is via taking the head apart? Although I bet a back purge could get most if not all out.

OK that's what I thought. I didn't understand how you thought EGR was related since I would have thought that carbon would've been burned off on the cylinder and not accumulate. I was thinking a combination of low cetane (ie. dirtier burn) coupled with low rpms (city drivings) were the cause.

I really know very little about this stuff.

I was thinking EGR caused carbon build up in the intake and the carbon traveled from there to the head. I could be way off but I had an EGR on my truck go bad and do exactly that to the intake(honestly did not have the heads looked at since was costing so much already). Poor combustion could of course eventually cause carbon in the head but I'd think it would take longer to happen since the combustion happens in the combustion chamber. I am though assuming the excessive carbon build up is on the intake side of the head and not exhaust. All pure speculation on my part.