Strange 330D boost issue.

Banny · 28 May 2010 at 08:55

Mates car seems to be losing boost at random times, can happen at any revs.
He said the turbo is still working just no power, blip the throttle a couple of times and its fine again.
The only stuff we have done to car is cleaned the EGR valve out, could it be a split vacuum pipe or something?
It can't be a boost leak surely as the symptoms would be there all the time you would think.
Thanks for any help.

Django x2 · 28 May 2010 at 10:33

MAF Failure.

Simples

Banny · 28 May 2010 at 14:47

it is not going into limp mode though, ever I thought when the MAF went it would go into limp mode.

Axeboy · 28 May 2010 at 18:51

I had a similar issue with my 5 series and dealer said they changed the plugs and particulate filter.... seems to have solved the issue...

Django x2 · 28 May 2010 at 18:52

Nope, the MAF doesn't work like that. It runs a predefined map from the ECU. Once the MAF get dirtly or fails, the ECU doesn't know how much air is coming in against the ECU map data so you either overfuel or get no boost.

Just try unplugging the MAF for a run and see how it goes. You won't do any damage as the ECU will run a default map.

Banny · 28 May 2010 at 19:10

Axeboy said:
I had a similar issue with my 5 series and dealer said they changed the plugs and particulate filter.... seems to have solved the issue...

No plugs and particle filter been done and has also just had inspection 2

Banny · 28 May 2010 at 19:12

Lucero said:
Nope, the MAF doesn't work like that. It runs a predefined map from the ECU. Once the MAF get dirtly or fails, the ECU doesn't know how much air is coming in against the ECU map data so you either overfuel or get no boost.

Just try unplugging the MAF for a run and see how it goes. You won't do any damage as the ECU will run a default map.

Will tell him to try it, would this explain why it does it every now and then at no predefined moment and in any gear.

Django x2 · 29 May 2010 at 17:23

Banny · 29 May 2010 at 21:28

Thanks Lucero

Dave L · 30 May 2010 at 06:56

Banny said:
No plugs and particle filter been done and has also just had inspection 2

A 330d doesn't have plugs (if you are referring to spark plugs, that is!)

Particulate Filter been replaced?? I think you are getting confused here.......these were only fitted to E90 chassis cars - and cost a fortune to replace......

Axeboy · 30 May 2010 at 09:28

That was my 530d...

glow plugs and particulate filter were changed

IAmATeaf · 30 May 2010 at 10:38

Axeboy said:
That was my 530d...

glow plugs and particulate filter were changed

Isn't a particulate filter more to do with the AC?

Axeboy · 30 May 2010 at 11:05

http://en.wikipedia.org/wiki/Diesel_particulate_filter

IAmATeaf · 30 May 2010 at 11:17

Axeboy said:
http://en.wikipedia.org/wiki/Diesel_particulate_filter

Oh right, so even when they're working they're not really?

Judging by the smoke I've seen coming from the exhaust when a diesel driver floors it.

Axeboy · 30 May 2010 at 11:20

Im not up to speed, but sure that only some TD's have them

Django x2 · 30 May 2010 at 11:21

not all diesels have them, My 530d doesn't smoke under boost at all. (Apart from when its been overfilled with oil that is.....

)

Banny · 8 Jun 2010 at 11:53

Quick update on this, we have unplugged the MAF and the problem is still there at random intervals RPM etc, with the MAF unplugged the performance in slightly down which would point to the fact the mixtures arn't optimised would this point to the MAF being OK.
Going to leave it unplugged for a week see if it gets any better, any new ideas on this as we are scratching our heads over it.

Banny · 9 Jun 2010 at 09:36

So no one has any ideas, OK any good independants in the North Hampshire area, as the car can be dangerous to drive, especially when pulling out of roundabouts, as this happens randomly, i.e pull off then bang no go, rather him than me.
Looks like its gonna have to have a laptop plugged into the OBD to hopefully find the problem.

Banny · 10 Jun 2010 at 13:45

so no ideas of any really good specialist not some rip off back door garage.

Banny · 30 Nov 2010 at 13:49

I would just like to revive this thread just so people are aware of the problem.
Right its been a long time and a lot of money spent and as of this moment it is still not fixed.
Was told it was the MAF it wasn't then told turbo this is where it gets good.
went on real OEM for the part number and then proceeded to source a decent seconhand turbo which we managed to find, to it to our independent only to be told it doesn't fit as it is mechanical not electrically controlled so there was the first waste of money, turbo was almost new aswell.
So the mechanic orders a brand new turbo from garrot and low and behold it is exactly the same as the one we had bought so real OEM part numbers for an 04 330d are wrong.
Well the turbo is fitted also the mechanic changes the oil just to be sure even though it was changed 2mth previously didn't want to void the warranty so did it anyway.
Take it for a test drive and its still exactly the same as it was.
Been put on diagnostics and comes up with no errors at all even unplugged MAF.
So now even the specialist is scratching his head, gonna phone some top man from BMW today and see if anything can be found out.
I will keep this updated incase someone else gets the same problem before they shell out loads of cash for a new turbo.
We are just hoping the specialist is good about it as he diagnosed it to be a turbo and it is still the same, he is a good bloke and well respected so should be fine.
Maybe some members might know him his name is Lee and he works out of Bentley always busy so must be pretty good.
Oh as for the smoke on start up found what that was, my friend and took it to someone else who said it was the glow plugs so changed all six and it was still the same but the fella failed to realise it was the control unit that has failed, so that was a waste of money, goes to show there are some cowboys out there who think they know what they doing.