BMW slow acceloration

a2b1972 · 01-08-2010, 02:00 PM

Hi i have a bmw 320d which has slow acceloration and is sluggish in lower gears. What could the problem be?

ElegantSpoon · 01-08-2010, 02:03 PM

Is this a new fault? Could be weather related

M3-FAST · 01-08-2010, 02:20 PM

Quote:

Originally Posted by a2b1972

Hi i have a bmw 320d which has slow acceloration and is sluggish in lower gears. What could the problem be?

Ice?

Mine is that slow at the moment it does approx 100 yards per minute!

shane55 · 01-08-2010, 02:28 PM

Doubt its the weather i think diesel is good down to about -20degC...and apparently all diesel BMWs have a fuel filter heater

Ham09 · 01-08-2010, 03:38 PM

Quote:

Originally Posted by a2b1972

Hi i have a bmw 320d which has slow acceloration and is sluggish in lower gears. What could the problem be?

Could be in limp home mode. Any lights on the dash that aren't normally there? Take it into the stealers if your not sure.

Ham09 · 01-08-2010, 03:43 PM

Quote:

Originally Posted by shane55

Doubt its the weather i think diesel is good down to about -20degC...and apparently all diesel BMWs have a fuel filter heater

Regular diesel starts to wax at -10c, so it is possible that your fuel filter is getting clogged. Depends where you get your fuel from, premium stuff I expect would be better.

a2b1972 · 01-09-2010, 06:23 AM

thanks 4 your help so far but i have recently changed the fuel filter. Do you think it has something to do with the throttle adaption?

Dr Dave · 01-09-2010, 07:18 AM

No.

MAF sensor issues perhaps? Common problem on many modern diesel cars.

E92Fan · 01-09-2010, 07:20 AM

No, unlikely to be a MAF sensor failure either, given that it's so damn cold and the air so dense. More likely to be a turbo hose coming loose, or one of the filters getting clogged. Just because the fuel filter has been changed recently doesn't mean that it could be clogged now. Unlikely though granted.

Why do you ask if it's the throttle adaptations? Have you recently had the car reset or recoded? If not, then it's unlikely that it's readapted again.

a2b1972 · 01-09-2010, 08:16 AM

This problem started before it was cold. So it cant be the cold?

Dr Dave · 01-09-2010, 08:31 AM

Needs looking at by someone who knows what they are doing to interpret live data especially airflow etc as MAF sensor problems are not *always* picked up by the actuation of the MIL.

Reduced low down power and general engine "lethargy" is a giveaway of MAF problems.

Simply unplugging the MAF and then checking if performance is better is a simple test most people can do. Unplugged it reverts to a safe default signal which should give half-decent performance.

MAF contamination by ingestion of road salt was a big problem on many cars recently. OEM's suggested cleaning them by distilled water etc but it wasn't very successful. Replacement via the exchange scheme was the only option. They used to be mega-expensive but aren't so nowadays - steer clear of ebay ones though.

01-08-2010, 02:00 PM	#1
a2b1972 New Member 6 Rep 27 Posts Drives: BMW e90 M Sport Join Date: Nov 2009 Location: Birmingham UK iTrader: (0)	BMW slow acceloration Hi i have a bmw 320d which has slow acceloration and is sluggish in lower gears. What could the problem be?
	Appreciate 0 Tweet Quote

01-08-2010, 02:03 PM	#2
ElegantSpoon There I was balls deep in a... 29 Rep 1,470 Posts Drives: BMW E90 320D Join Date: Oct 2008 Location: Devon, UK iTrader: (0)	Is this a new fault? Could be weather related __________________ BMW E90 320D Sapphire Black, Angel Eyes, BMW Performance Extras, Carbon Fabric Trim
	Appreciate 0 Quote

01-08-2010, 02:28 PM	#4
shane55 First Lieutenant 32 Rep 336 Posts Drives: BMW 330d M-Sport Auto Join Date: Oct 2009 Location: IRL iTrader: (0)	Doubt its the weather i think diesel is good down to about -20degC...and apparently all diesel BMWs have a fuel filter heater __________________ Sapphire Black* Darklines* Black Dakota Leather* Heated Seats* Professional Navigation* Xenons* High Beam Assist* Hi-Fi* USB Audio* DAB* BMW Assist* Sun Protection Glass
	Appreciate 0 Quote

01-09-2010, 06:23 AM	#7
a2b1972 New Member 6 Rep 27 Posts Drives: BMW e90 M Sport Join Date: Nov 2009 Location: Birmingham UK iTrader: (0)	thanks 4 your help so far but i have recently changed the fuel filter. Do you think it has something to do with the throttle adaption?
	Appreciate 0 Quote

01-09-2010, 07:18 AM	#8
Dr Dave Zummerzet Zyder Drinker! 112 Rep 5,541 Posts Drives: '06 330D Le Mans Blue Join Date: May 2009 Location: Somerset iTrader: (3) Garage List 2006 330d M Sport [0.00]	No. MAF sensor issues perhaps? Common problem on many modern diesel cars. __________________
	Appreciate 0 Quote

01-09-2010, 07:20 AM	#9
E92Fan Moderator 324 Rep 5,493 Posts Drives: . Join Date: Aug 2007 Location: . iTrader: (0)	No, unlikely to be a MAF sensor failure either, given that it's so damn cold and the air so dense. More likely to be a turbo hose coming loose, or one of the filters getting clogged. Just because the fuel filter has been changed recently doesn't mean that it could be clogged now. Unlikely though granted. Why do you ask if it's the throttle adaptations? Have you recently had the car reset or recoded? If not, then it's unlikely that it's readapted again. __________________ ... ... ... DMS Remap Review ----- Quaife LSD Review ----- Hartge Antiroll Bars Review ----- Bilstein PSS10 B16 Ride Control Review ----- Detail by ShineOn ----- Paintshield Review
	Appreciate 0 Quote

01-09-2010, 08:16 AM	#10
a2b1972 New Member 6 Rep 27 Posts Drives: BMW e90 M Sport Join Date: Nov 2009 Location: Birmingham UK iTrader: (0)	This problem started before it was cold. So it cant be the cold?
	Appreciate 0 Quote

01-09-2010, 08:31 AM	#11
Dr Dave Zummerzet Zyder Drinker! 112 Rep 5,541 Posts Drives: '06 330D Le Mans Blue Join Date: May 2009 Location: Somerset iTrader: (3) Garage List 2006 330d M Sport [0.00]	Needs looking at by someone who knows what they are doing to interpret live data especially airflow etc as MAF sensor problems are not always picked up by the actuation of the MIL. Reduced low down power and general engine "lethargy" is a giveaway of MAF problems. Simply unplugging the MAF and then checking if performance is better is a simple test most people can do. Unplugged it reverts to a safe default signal which should give half-decent performance. MAF contamination by ingestion of road salt was a big problem on many cars recently. OEM's suggested cleaning them by distilled water etc but it wasn't very successful. Replacement via the exchange scheme was the only option. They used to be mega-expensive but aren't so nowadays - steer clear of ebay ones though. __________________
	Appreciate 0 Quote