2009 320D N47 Stutter under light load

[BarendH]

Hi I bought a E90 320d with 192000 km in a good condition. After the purchase I realised the engine has a very specific problem under very specific condition.
At idle the engine is very smooth. Within the first km, if I accellerate lightly, about 10% pedal, the engine stutters almost as if it is missing. then when I am cruising at around 60 km/h, the revs are jumping up about 200 rpm every second. The frequency stays mostly the same. When I then push the accelerator a little more, the stutter stops. If I lift the accelerator completely, then there is no stutter or jumping. My BMW trained machanic that I know for 22 years, have been assisting and we changed and tested the following since purchase:

• Replaced all the turbo pipe o-rings
• replaced the Tappet cover breather and breather pipe
• Tested for vacuum leaks - all repeared
• deleted the EGR by removing the cooler section, blocking the exhaust and inlet side and blocloff the coolend ports.
• replaced all the injectors with OEM Bosch
• disconnected the MAF - no change
• Disconnected the swirl flaps and kept it in both positions - no differnce. Swirl flapps are clean and works properly
• Replaced the Fuel Quantity Control Valve
• Monitored the diesel pressure which is within range. The MAP flow and diesel pressure changes in sync with the rev jumps
• Remapped Stage 2 - resulted in great power, smooth acceleration under load, good fuel consumption at about 17 km/l in town and 20 km/l on highway. It did not resolve the stutter or rev jump.

None of the above made a difference to thie specific issue, but resolved other issue. Currently no DTC error and none detected while driving with the issue.
Any Suggestions?

Who would be able to diagnose this issue properly without throwing the parts bin.

 

[Spanky]

Gear specific? If not, perhaps the throttle peddle itself

 

[BarendH]

Not gear specific, replaced throttle peddle also. Revs between 1400 - 1900 rpm

 

[Shaheenem]

If it's an automatic, check your torque converter. Had similar issues on the vehicle both n47 with 6hp19 / 6hp21 gearboxes and the torque converter was at fault.

 

[BarendH]

The Gearbox and torque convertor has been exchanged. We thought that it might be the lockup clutch releasing and engaging. Unfortunately it did not make a difference.

Any suggestion on who might be the right person to look at it in the Centurion, Midrand, Pretoria area?

 

[AngusCPB]

Hi, I also had this issue with my 2009 320d (Also remapped). What I found was that with the 130kw variants (Pre-2010), the torque converters are different. The 130kw 320d's have the Q126 torque converter, whilst the 135kw have the S126 torque converter. I replaced just the torque converter with one from a 2010 320d and the problem was fixed. I believe the Q126 torque converter cannot handle the additional torque from the remap.

 

[BarendH]

Hi @AngusCPB. The issue was noticed just after I bought the car and before I changed anything. Almost all work was done to try to resolve this issue. The replacement gearbox is of a 2010 320D with 150k. No changes after it. The stutter is a high frequency, almost like a miss fire, but just under light acceleration between 1500 - 1900 rpm. It makes it very difficult to drive smoothly and economically, as you either have to be almost off the pedal or just a bit deeper than normal. If I drive a little bit aggressive, it is smooth and very powerful, although it does give a puff of Blck smoke.

 

[mohanniel]

Hi everyone, I'm facing a problem with my 2014 320D after making some modifications, including a Hybrid turbo, Drop in filter, larger intercooler, EGR delete, and a full exhaust system, plus a remap. Post-installation of the larger intercooler, I've noticed a slight vibration in the engine, felt through the floor and steering wheel at low RPMs, alongside a louder engine noise and a decrease in exhaust tone. Despite my efforts, I haven't been able to pinpoint the issue. There are no electronic faults detected, and the mountings and vibration dampers seem fine. Any insights on what might be causing this would be greatly appreciated.

 

[DRCraig]

A mate of mine had the same shudder under load on his E82 120d below 2000rpm. The tuner pinpointed the problem to some loose intercooler pipe. Apparently the issue subsided. Worth checking it out.