[SomeRandomer123]

Hey,
Our 330d misfires on cold starts. Think its injector related. When its warm, idle can be normal or slightly rougher than usual. It misfires most times on cold starts but varys in severity.
Here is a video of this mornings cold start. http://www.youtube.com/watch?v=5zPk2Wg0Vf8

[SomeRandomer123]

Sorry for the numerous posts - this App is useless! I'd say about 50% severity. When you start driving, all returns to normal. It sometimes fully misfires but I am yet to get a video of it - I will post a link back here when it REALLY Misfires.
Diagnosis please!
58k miles.

[Coolieman1220]

how can a diesel misfire? there's no spark

[SomeRandomer123]

It uses glows - at the end of the day the fuel is being ignited the same as Petrol to push the cylinder down. There is a problem with one of the cylinders - evidently not firing correctly = misfire. The problem is the same. There is a smell of unburnt fuel.

[Quasimodem]

Originally Posted by SomeRandomer123

It uses glows - at the end of the day the fuel is being ignited the same as Petrol to push the cylinder down. There is a problem with one of the cylinders - evidently not firing correctly = misfire. The problem is the same. There is a smell of unburnt fuel.

Compression ignition, but of course there is an explosion, my uneducated guess -- likely something wrong with injector or the common rail system, if a cylinder is not burning efficiently. Then again maybe a valve problem or hpfp.

[SomeRandomer123]

Does the 30d have a HPFP?

[Quasimodem]

Originally Posted by SomeRandomer123

Does the 30d have a HPFP?

IMHO, because of the higher compression of diesel engines (necessary because there is no spark) they pretty much always run higher pressure fuel pumps (the heavier fuel might also require more pressure to get it to the right place). But diesel engines have the advantage in that their fuel doubles as a lubricant so the fuel system is generally more reliable. Another advantage of diesel is that has a higher flash point and can be tough to ignite in an accident (a pity because from the posts I see on this forum it appears that 335i owners would be more likely to take advantage of this feature than 335d owners).

[Falafel Combo]

Side note: diesels redline at 4800?

[SomeRandomer123]

Originally Posted by shicobico

Side note: diesels redline at 4800?

Actual Rev Limiter is at 5000rpm. Red line starts at 4800.

[SomeRandomer123]

We were going to wait till service (month or two) to have the problem sorted but the smell of unburnt fuel means I want it in ASAP. The unburnt fuel can contaminate the catalyctic converter, melt the catalyst and/or block the exhaust causing a vehicle fire.
So all the problems that 335i owners have with HPFP Failure all over this forum, can the same HPFP be related to the 30d?

[Quasimodem]

Originally Posted by SomeRandomer123

We were going to wait till service (month or two) to have the problem sorted but the smell of unburnt fuel means I want it in ASAP. The unburnt fuel can contaminate the catalyctic converter, melt the catalyst and/or block the exhaust causing a vehicle fire.
So all the problems that 335i owners have with HPFP Failure all over this forum, can the same HPFP be related to the 30d?

No known problem with the 335d hpfp. Of course, everything eventually fails, so I am sure some have gone out. Yes, you should take it in immediately to the dealer though they may charge you for the diagnosis if it is out of warranty. You are quite right, unburnt diesel will undoubtedly cause problems with the Diesel Particulate Filter.

Funny, i dont pay much attention to the Tach since the 335d is an automatic and I rarely use the paddle shifters. So I can't recall where the redline is. Diesels run like bigger engines, everytime the crank spins it produces more power than the equivalent gas engine, so the crank just doesnt need to spin as fast to produce the same power.

[SomeRandomer123]

Originally Posted by Quasimodem

No known problem with the 335d hpfp. Of course, everything eventually fails, so I am sure some have gone out. Yes, you should take it in immediately to the dealer though they may charge you for the diagnosis if it is out of warranty. You are quite right, unburnt diesel will undoubtedly cause problems with the Diesel Particulate Filter.

Funny, i dont pay much attention to the Tach since the 335d is an automatic and I rarely use the paddle shifters. So I can't recall where the redline is. Diesels run like bigger engines, everytime the crank spins it produces more power than the equivalent gas engine, so the crank just doesnt need to spin as fast to produce the same power.

Can unburnt diesel create any other problems? We have Particulate Filter and Catalytic Converter...

[Thud]

Originally Posted by SomeRandomer123

It uses glows - at the end of the day the fuel is being ignited the same as Petrol to push the cylinder down. There is a problem with one of the cylinders - evidently not firing correctly = misfire. The problem is the same. There is a smell of unburnt fuel.

Glows are only used to preheat the combustion chamber prior to starting the engine in extremely cold weather.

Maybe there's a compression problem in one of the cylinders? More likely it's a fuel system problem though.

[Thud]

Originally Posted by shicobico

Side note: diesels redline at 4800?

Yes, limited by the laws of physics, even the Audi race diesels shift below 5000rpm.

Bigger diesels redline lower, like the 6.7L motor used in Dodge trucks which redlines at just over 3000rpm (350hp and 800tq)

[SomeRandomer123]

Originally Posted by Thud

Yes, limited by the laws of physics, even the Audi race diesels shift below 5000rpm.

Bigger diesels redline lower, like the 6.7L motor used in Dodge trucks which redlines at just over 3000rpm (350hp and 800tq)

Yes the 20d redlines about 5500rpm - 6000rpm - noticibely higher than the 30d and 35d anyway!

[SomeRandomer123]

So why does the car run fine and normal when you start driving? This is a tricky one! Compression doesn't increase with RPM, just happens more often - correct?

[SomeRandomer123]

Good news! Problem sorted It was a faulty Glow Plug Control Unit so a new one was fitted under warranty. Job's a gooden. Running on all 6 nicely again!!

[Quasimodem]

Originally Posted by SomeRandomer123

Good news! Problem sorted It was a faulty Glow Plug Control Unit so a new one was fitted under warranty. Job's a gooden. Running on all 6 nicely again!!

Interesting, but arent glow plugs only used when the engine is really cold such as in colder climates? Was the Glow Plug Control actually activating them when they were not needed? So this could happen to anybody. Or did you need them when starting the car and they didnt function properly?

[Forsazh]

Hey guys this is my first post. Just a tidbit you might find interesting. I drive a Mack truck and it redlines at 2100 rpm.

[SomeRandomer123]

Originally Posted by Quasimodem

Interesting, but arent glow plugs only used when the engine is really cold such as in colder climates? Was the Glow Plug Control actually activating them when they were not needed? So this could happen to anybody. Or did you need them when starting the car and they didnt function properly?

I think both... I don't think they were coming on properly at cold start and I think they were coming on when it was warm, overheating it and causing excessive emissions. The OBD-II would've shown that all six glows had failed so the BMW engineers interpret this to mean faulty Control Unit.

[SomeRandomer123]

Originally Posted by Forsazh

Hey guys this is my first post. Just a tidbit you might find interesting. I drive a Mack truck and it redlines at 2100 rpm.

Mmmm yes, that was mildly interesting!