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BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Mark Robins on October 7, 2010, 9:14 am

Year of Manufacture *: 2005
Engine Size and Code *: 2.0
( Optional) Fault Codes: 3FF0, 4298.

First scan OK
second scan fault present.
3FF0 Air mass meter
4298 Lambda sond, bank 1
Vehicle was presented to me after it had been to a BMW specialist, with my level of diagnostic equipment I didn’t really want to take it on but as a favour to this long standing customer I said I’d take a look.
The vehicle has a huge lack of power until it reaches around 3000 rpm and then takes off like a scalded cat! It has been previously fitted with new injectors, inlet manifold and air mass meter all OEM parts. I scoped the priming pump (OK), injector signal (OK) I.M.V. and pressure regulator but when I scoped the fuel pressure sensor it doesn’t develop it’s pressure in a linear fashion when accelerating, the pressure remains low until the revs get to 3000 and then the pressure goes up to what I would consider normal. During this period there is a missy feeling to the engine, I wasn’t sure this was a symptom or an actual fault so I scoped the manifold pressure sensor and sure enough the turbo had the same non linear build up of boost. I bit the bullet and removed the turbo but found nothing wrong with it the variable vanes were all perfectly free and very little in the way of carbon deposits. The strange thing was after refitting the turbo the car returned to normal so I re tested the fuel pressure and sure enough pressure development was back to normal! After about 5 mins the fault re-established itself, I talked to the previous garage about the fault and they said that after fitting the AMM they had the same thing the car recovered it’s performance for a short period of time. I’m now at the point of having the ECM tested if possible, any ideas would be really helpful?
Sorry for the long post.

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Andrew West <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5350' width='330' height='300' border=0 style='border:none;'> on October 8, 2010, 10:41 pm, in reply to "BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"
Andrew West

Hello Mark,
could it be a fault with the rail pressure sensor or its' connection? or possibly a sticking IMV?
regards, Andrew

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Dave Hill <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT2783' width='330' height='300' border=0 style='border:none;'> on October 9, 2010, 4:16 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"

Hi Mark

Your fault description suggests that the turbo is not spooling up & generating necessary boost at lower engine speeds. Perhaps there is a problem with the boost control system? Is it vacuum controlled or does it have an electronic actuator?

If its vac controlled, can you activate it with a Mitty Vac & see if low RPM boost is achieved?

You need to establish if the ECU is commanding an increased boost that is not being achieved, or otherwise.

You may have a subtle charge system leak, although unlikely seeing that the power was good for a moment.

I wonder if the new MAF is the correct one?

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on October 10, 2010, 12:17 am, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"
Mark Robins

Thanks for the replies, I disconnected the IMV and still had the problem; and watched the turbo actuator and it's calling for full boost all the time the performance is poor (It's an electronic acctuator), the pressure regulator is I think a possibility, but I dont have a blank valve to confirm it or one of those new remote pressure control units so it would have to be a guesstimate, the weird thing is the live data pressure demand is following the actual pressure so it suggests some other fault; although I'm not a avid fan of live data. The AMM is a new geniune unit (digital type) and to have identical problems with new and old is not probable; but as we all know not impossible. I'll post the results of a new pressure reg when I get it.
Thank's

Mark

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Piotr Sokolowski <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1848' width='330' height='300' border=0 style='border:none;'> on October 10, 2010, 10:03 am, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"

AMM maybe need adaptation

Link: www.pandpauto.eu

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Carl Ford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1822' width='330' height='300' border=0 style='border:none;'> on October 13, 2010, 10:20 am, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"
Carl Ford

Just had a 320d in today which is same engine as yours with exactly same fault apart from we only had a code for amm, after scoping and smoking could not find anything physically wrong, so with my apprentice holding the revs with the vehicle misfiring i got a screw diver and pushed open swirl valves and by magic fault dissapered i do beleive this maybe the fault with your if you have not already fixed it
hth
carl

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on October 13, 2010, 11:05 am, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"
Mark Robins

Carl you are definitely on to something, I just checked the car now, when first staring it there is no fault but the problem usually develops in a matter of seconds. So when we started it with no fault present I moved the flaps with my hand and the missy feel under acceleration was there. The weird thing is that after messing about under the manifold the fault has totally disappered. Now this is supposedly a known good second hand manifold, from what I can see I guess the flaps are operated by vacuum via a control solenoid but it's difficult to see so I'm focused on that at the moment.

Thanks to all for your insights will let you know how things progressed.

Mark

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Carl Ford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1822' width='330' height='300' border=0 style='border:none;'> on October 13, 2010, 11:27 am, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"
Carl Ford

Hi mark,
i have just taken the vaccum pipe of mine to test drive it and all is well so i have now checked the vacuum to the valves which is where i believe the problem lies and the valve does not start wasteing any vacuum until i rev out of the misfire which is keeping the valves closed, so i have ordered a new control solenoid will let you know how it goes.

HTH
Carl

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on October 13, 2010, 4:53 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"

This is power OK 2400 rpm upwards
approx

.
This is fault present idle to 2400 rpm rpm
Vacuum gauge confirms valve working according to PWM signal.

Carl,

I've got a feeling that we are barking up the wrong tree, I've just scoped the pwm signal to the control solonoid and it seems that on my vehicle it's doing exactly what the ECU is commanding, so I believe its a symptom and not the fault! I think the ECU is misinterpreting the load signal and the main input is I believe the AMM. I've got a Picoscope coming on Thursday and hopefully I can map frequency output from the AMM to prove this, I hope I'm wrong and you're right.

Mark

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Carl Ford <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1822' width='330' height='300' border=0 style='border:none;'> on October 13, 2010, 5:37 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"
Carl Ford

Hi mark,
maybe we are barking up the wrong tree or maybe yours could just be a case of the swirl valve sticking until a certain vacuum is reached, have you tried taking off the vaccum pipe to the swirl valves and trying it if that works i would take off the manifold and operate swirl valkves on the bench to observe there operation, worth a go i think as this will only actually cost you time and not any parts. I scoped my amm and could not really see anything apart from the digital waveform but just looked on pico site and seen the massey method so i will possibly try that next time has anyone else tried the massey method
regards
carl

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on October 13, 2010, 11:28 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"

Carl, if you got the 4000 series Picoscope they have some new software that converts the digital signal to analogue, I believe it's free but will only work on the 4000 series of scope. Make interpretation of the signal a lot easier.
I quote...

An option to measure frequency against time has now been added to PicoScope software (version 6.4.28 onwards). A trace from a turbocharged diesel vehicle is shown below. The vertical scale is in frequency.

Mark

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on October 18, 2010, 1:12 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) #"

Scoped the MAF sensor using Pico's new frequency software and can see nothing out of the way with the swirl flaps control vac pipe disconnected. Car drives fine like this and is not logging any DTC's. Not having stripped one of these manifolds does the flaps control long and short intake routes, because closing the flaps seems to strangle the engine on anything but tick-over I'm thinking that the ECU needs re-flashing.

Mark.

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on October 18, 2010, 6:22 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)"
Mark Carter

Hi Mark, the swirl flaps do what they say on the tin, they generate swirl.

The flaps are normally raised/operated at idle/low flow conditions. At higher Rpm/air flow there is no need to generate extra swirl. HTH

Regards Mark

Modern cars, Its all wizardry and witchcraft

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on October 18, 2010, 10:25 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)"
Mark Robins

Thanks for that Mark, looks like the ECU command regime is wrong and hopefully a re-flash will cure the problem.

Mark Robins

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)

Posted by jamie lambert <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1460' width='330' height='300' border=0 style='border:none;'> on April 27, 2014, 5:02 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)"
Jamie Lambert

Hi Mark

I know its a long time ago now but did you ever get to the bottom of this fault as I have the exact same fault with a bmw x3.

Regards Jamie

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)

Posted by Ian Slattery <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1196' width='330' height='300' border=0 style='border:none;'> on April 27, 2014, 8:08 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)"
Ian Slattery

Hi Jamie.

Take a look inside the inlet manifold, for restriction [black goo]. Also clean out the map sensor.

Does it run all right with swirl flaps disconnected?

Regards Ian

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)

Posted by jamie lambert <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1460' width='330' height='300' border=0 style='border:none;'> on April 27, 2014, 9:15 pm, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)"
Jamie Lambert

Hi Ian

Thanks for the reply, ive had the inlet manifold off and cleaned out best I can and also cleaned the egr. Also ive performed the bg induction clean on the inlet. Yes the car runs perfect with the swirl flaps disconnected. When I re-connect them fault code 3FFO is set after holding the revs at about 2250 rpm and the engine is very lumpy. Open the swirl flaps manually and the car is fine.

Regards Jamie.

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)

Posted by Scott Feaks <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3380' width='330' height='300' border=0 style='border:none;'> on May 8, 2014, 8:22 am, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)"
Scott Feaks

Hi, the 3ffo fault code is an indication that the inlet valves inside the cylinder head are badly carboned up resticting the air. The official BMW fix involves a cylinder head de-coke and replacing the inlet manifold, the manifold can sometimes be cleaned out. I have heard of some people managing to walnut blast the cylinder head.
regards
Scott

Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=ukat3563' width='330' height='300' border=0 style='border:none;'> on May 10, 2014, 10:37 am, in reply to "Re: BMW 120D 2.0 2005 - Poor performance until 3000 rpm (waveforms) # (update)"
Mark Robins

No not really, customer was satisfied to just blank off pipe to flap actuator as car was running fine and no faults were being logged, ECU was definitely not commanding vac solenoid to close.

P.S. car was sold on and he now has a MX5!

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