320d mpg and diesel smell issues

P40L · 12-18-2009, 03:45 PM

Hi all, as you can see iam new to this forum, just need a little advice from you guys.....

When i bought my 2006 320d Msport 2 months ago it was averaging 40mpg, over the last 3-4 weeks the mpg has went down to 26-30mpg town driving and i recently went on a 600mile round trip, didnt take it over 70mph and got 39mpg..imo thats really shocking!!!

Also when the car is ticking over i get a strong smell of diesel (has happened a couple of times when ive been driving too)

I took the car to a local independant, who plugged it into the computer, which nothing came back as a fault....he said it could be the partical filter??? didnt think mine came with one, just post LCI models???

I also had a little head to head (on a private road of course) with a 2005 140bhp passat....we were neck and neck to 100mph, had 4 runs and all the same result. I done this as my car didnt feel as quick anymore.

Today ive disconnected the MAF, as i got told this could be on its way out, it feels a little more responsive, but aint drove it that much to get a average mpg.

Any help would be much appreciated, as iam starting to rip my hair out...i sold my Evo to buy a more economical car haha

Thanks Paul

JLR1969 · 12-18-2009, 03:56 PM

Diesel cars always return worse MPG when its cold. Mine used to average 51MPG now its more like 41MPG

P40L · 12-18-2009, 04:12 PM

I could handle that for a couple of months a year, but there still must be something wrong as it smells of fuel?

Dr Dave · 12-18-2009, 05:31 PM

Fuel leak on the engine?

Remove engine top cover and look around by fuel injectors.

MEGA · 12-18-2009, 05:31 PM

TBH I have the exact same thing re: mpg and the occasional smell. I've ignored it till now. I always assumed the MPG was just down to my driving style

P40L · 12-18-2009, 05:48 PM

Quote:

Originally Posted by MEGA

TBH I have the exact same thing re: mpg and the occasional smell. I've ignored it till now. I always assumed the MPG was just down to my driving style

The recomended independant i took it to said there deffinatly is a problem, but to be honest i dont think he had a clue (said it could be the partical filter) and was going to charge me £100 to change something i dont have.

What sort of mpg are you getting?

MEGA · 12-18-2009, 06:03 PM

Average 25 but its remapped and only ever town driving wi' foot to the floor

So I always assumed it was just me.

But characteristics are exactly as you describe!

ElegantSpoon · 12-19-2009, 05:43 AM

I get 36mpg and only drive in town, I also get a smell of fuel some times but I thought that was just a diesel thing?

gIzzE · 12-19-2009, 10:25 AM

My 123d auto was down to 31mpg last week, only short (sub 10 mile) journeys or round town, which diesels hate anway, and when it is below 5°c out there the car doesn't even warm up.

My 4 wheel drive auto big heavy A6 estate is getting 28mpg still, and that is a 3.2 V6 petrol.

Take it onto the motorway with it warm, and sit at 70mph and reset it, it should be showing 45mpg doing this. If it is not then you have a problem.

gIzzE · 12-19-2009, 10:27 AM

Oh, I should just add that I was averaging 55mpg in the 1er up till mid November and then it dropped to 45mpg, then to 39.7mpg.
Reset it on the last fill up and now 31mpg, diesels hate short cold journeys.

Petem95 · 12-19-2009, 02:28 PM

That sounds very poor to me. Only using my 330d for commuting in rush hour still averages over 40mpg.

On an 900+ mile trip around Scotland, 3 up with luggage it still managed 45 and that wasn't driving for economy!

As mentioned there is no doubt diesels take a fairly big knock in MPG in cold weather. My previous Audi 2.0 TDi used to lose 5-6MPG in the winter.

Regarding the diesel smell, just check all the fuel lines under the bonnet. There will basically only be the one fuel line coming from the fuel tank going to the injectors, so won't be difficult to see.

F104 · 12-19-2009, 02:38 PM

just from a physical point of view, between +25C and -5C air density increases by just over 11%. Air resistance is likely about 80% of power requirements under normal conditions, so 80% of 11% goes for sure in fuel economy.
Next largest is power losses in tyre/road friction, and that is probably increasing a lot more with rain sleet, snow etc. And then we all use the seat heaters, the electrical grid heater will come in when coolant is still cold etc etc. So expect at least 10% worse fuel between summer and winter.
In addition, in winter you have the complication of heating up some 600 lbs of metal in engine and transmission from sub zero to summer temps before you're equal to summer conditions. That will take some fuel too, and kill you on short distances.

gIzzE · 12-19-2009, 04:07 PM

Quote:

Originally Posted by Petem95

That sounds very poor to me. Only using my 330d for commuting in rush hour still averages over 40mpg.

On an 900+ mile trip around Scotland, 3 up with luggage it still managed 45 and that wasn't driving for economy!

As mentioned there is no doubt diesels take a fairly big knock in MPG in cold weather. My previous Audi 2.0 TDi used to lose 5-6MPG in the winter.

Regarding the diesel smell, just check all the fuel lines under the bonnet. There will basically only be the one fuel line coming from the fuel tank going to the injectors, so won't be difficult to see.

I find there is really very little MPG wise between a 320d, 325d and 330d, they all seem to return the same for me.

Dr Dave · 12-20-2009, 04:24 AM

Quote:

Originally Posted by Petem95

That sounds very poor to me. Only using my 330d for commuting in rush hour still averages over 40mpg.

On an 900+ mile trip around Scotland, 3 up with luggage it still managed 45 and that wasn't driving for economy!

Pete, how the hell are you getting such figures! 45 on a run might be achieveable but >40 on a commute is a no-no!

NFS · 12-20-2009, 05:36 AM

I drove a 330d for a week and got 32mpg. Mix of urban and motorways.

ElegantSpoon · 12-20-2009, 06:43 AM

I think what F104 has said explains things. I only do short 10min drives most the time so the poor bugger never gets warm! I always put my heated seat on and the heaters on full whack!

beemerbird · 12-20-2009, 07:13 AM

Quote:

Originally Posted by F104

just from a physical point of view, between +25C and -5C air density increases by just over 11%. Air resistance is likely about 80% of power requirements under normal conditions, so 80% of 11% goes for sure in fuel economy.
Next largest is power losses in tyre/road friction, and that is probably increasing a lot more with rain sleet, snow etc. And then we all use the seat heaters, the electrical grid heater will come in when coolant is still cold etc etc. So expect at least 10% worse fuel between summer and winter.
In addition, in winter you have the complication of heating up some 600 lbs of metal in engine and transmission from sub zero to summer temps before you're equal to summer conditions. That will take some fuel too, and kill you on short distances.

Pretty much sums it up imo.

The old addage used to be "you do enough annual mileage to warrant the outlay of buying a diesel". Think that has changed now but I wouldn't worry too much about the mpg as above.

Keep your nose keen re. the diesel smell though as my 335d never produced any such wiffs. Take it your car has a FBMWSH? Try taking it for a good long run, diesels are at their best when running at optimum temperature, hence they love motorway runs.

Dr Dave · 12-20-2009, 08:01 AM

Quote:

Originally Posted by ElegantSpoon

I think what F104 has said explains things. I only do short 10min drives most the time so the poor bugger never gets warm! I always put my heated seat on and the heaters on full whack!

Short runs are so not good for an engine!

ElegantSpoon · 12-20-2009, 11:11 AM

Indeed they are not just drove for two hours and I think she loved it

Dr Dave · 12-20-2009, 12:07 PM

Quote:

Originally Posted by NFS

I drove a 330d for a week and got 32mpg. Mix of urban and motorways.

that's exactly what mine returns.

fuzzer123456 · 12-20-2009, 07:30 PM

They change the diesel to stop it freezing in winter, remember the days gone by of lorry drivers building fires under their diesel tanks? well alas no more due to whatever they do to the fuel

upside , doesnt freeze .. downside , less MPG. Mix that with cold weather , heater , heated rear window , heated seats , headlights and the engine not warming up and welcome to winter MPG mode.

Martin 335d · 12-20-2009, 10:18 PM

Quote:

Originally Posted by MEGA

Average 25 but its remapped and only ever town driving wi' foot to the floor

So I always assumed it was just me.

But characteristics are exactly as you describe!

How on earth can you average that in a 320d??? Even driving like a hoon I would be very upset if I was averaging that in a 320d

OP and Mega get your cars checked out, even in the late cold weather my 335d is still averaging 29mpg in town, and it has been remapped too. I am not exactly hard on the car everyday mind you but it's not driven like little miss daisy either

12-18-2009, 03:45 PM	#1
P40L Enlisted Member 2 Rep 30 Posts Drives: 320d Join Date: Dec 2009 Location: North East iTrader: (0)	320d mpg and diesel smell issues Hi all, as you can see iam new to this forum, just need a little advice from you guys..... When i bought my 2006 320d Msport 2 months ago it was averaging 40mpg, over the last 3-4 weeks the mpg has went down to 26-30mpg town driving and i recently went on a 600mile round trip, didnt take it over 70mph and got 39mpg..imo thats really shocking!!! Also when the car is ticking over i get a strong smell of diesel (has happened a couple of times when ive been driving too) I took the car to a local independant, who plugged it into the computer, which nothing came back as a fault....he said it could be the partical filter??? didnt think mine came with one, just post LCI models??? I also had a little head to head (on a private road of course) with a 2005 140bhp passat....we were neck and neck to 100mph, had 4 runs and all the same result. I done this as my car didnt feel as quick anymore. Today ive disconnected the MAF, as i got told this could be on its way out, it feels a little more responsive, but aint drove it that much to get a average mpg. Any help would be much appreciated, as iam starting to rip my hair out...i sold my Evo to buy a more economical car haha Thanks Paul
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12-18-2009, 03:56 PM	#2
JLR1969 Major General 1843 Rep 7,000 Posts Drives: Kubota GR1600 Join Date: Dec 2008 Location: England iTrader: (1)	Diesel cars always return worse MPG when its cold. Mine used to average 51MPG now its more like 41MPG
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12-18-2009, 04:12 PM	#3
P40L Enlisted Member 2 Rep 30 Posts Drives: 320d Join Date: Dec 2009 Location: North East iTrader: (0)	I could handle that for a couple of months a year, but there still must be something wrong as it smells of fuel?
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12-18-2009, 05:31 PM	#4
Dr Dave Zummerzet Zyder Drinker! 116 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]	Fuel leak on the engine? Remove engine top cover and look around by fuel injectors. __________________
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12-18-2009, 05:31 PM	#5
MEGA Dieseasal 210 Rep 6,881 Posts Drives: LCI E92 335d M-Sport Join Date: Jan 2009 Location: Harrow, London iTrader: (2)	TBH I have the exact same thing re: mpg and the occasional smell. I've ignored it till now. I always assumed the MPG was just down to my driving style __________________ Previously: 2003 Peugeot 206 1.6 8v \| 2006 E90 320d M-Sport, 19" BBS CH, Full Ice-cold JL audio install, August 2010 Total BMW 6 page feature car. \| 2003 Nissan 350Z GT Coupe 286BHP Now:2010 E92 LCI 335d M-Sport
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12-18-2009, 06:03 PM	#7
MEGA Dieseasal 210 Rep 6,881 Posts Drives: LCI E92 335d M-Sport Join Date: Jan 2009 Location: Harrow, London iTrader: (2)	Average 25 but its remapped and only ever town driving wi' foot to the floor So I always assumed it was just me. But characteristics are exactly as you describe! __________________ Previously: 2003 Peugeot 206 1.6 8v \| 2006 E90 320d M-Sport, 19" BBS CH, Full Ice-cold JL audio install, August 2010 Total BMW 6 page feature car. \| 2003 Nissan 350Z GT Coupe 286BHP Now:2010 E92 LCI 335d M-Sport
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12-19-2009, 05:43 AM	#8
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)	I get 36mpg and only drive in town, I also get a smell of fuel some times but I thought that was just a diesel thing? __________________ BMW E90 320D Sapphire Black, Angel Eyes, BMW Performance Extras, Carbon Fabric Trim
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12-19-2009, 10:25 AM	#9
gIzzE Major General 361 Rep 5,985 Posts Drives: F11 + 997 Carrera S Join Date: Apr 2006 Location: Norfolk, UK. iTrader: (2)	My 123d auto was down to 31mpg last week, only short (sub 10 mile) journeys or round town, which diesels hate anway, and when it is below 5°c out there the car doesn't even warm up. My 4 wheel drive auto big heavy A6 estate is getting 28mpg still, and that is a 3.2 V6 petrol. Take it onto the motorway with it warm, and sit at 70mph and reset it, it should be showing 45mpg doing this. If it is not then you have a problem.
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12-19-2009, 10:27 AM	#10
gIzzE Major General 361 Rep 5,985 Posts Drives: F11 + 997 Carrera S Join Date: Apr 2006 Location: Norfolk, UK. iTrader: (2)	Oh, I should just add that I was averaging 55mpg in the 1er up till mid November and then it dropped to 45mpg, then to 39.7mpg. Reset it on the last fill up and now 31mpg, diesels hate short cold journeys.
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12-19-2009, 02:28 PM	#11
Petem95 Private First Class 21 Rep 110 Posts Drives: 2008 330d M-Sport Join Date: Nov 2009 Location: Leeds, UK iTrader: (0)	That sounds very poor to me. Only using my 330d for commuting in rush hour still averages over 40mpg. On an 900+ mile trip around Scotland, 3 up with luggage it still managed 45 and that wasn't driving for economy! As mentioned there is no doubt diesels take a fairly big knock in MPG in cold weather. My previous Audi 2.0 TDi used to lose 5-6MPG in the winter. Regarding the diesel smell, just check all the fuel lines under the bonnet. There will basically only be the one fuel line coming from the fuel tank going to the injectors, so won't be difficult to see. __________________ 2008 E92 330d M-Sport, Sapphire Black, 19" 225M's
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12-19-2009, 02:38 PM	#12
F104 Captain 19 Rep 732 Posts Drives: E92 320D M-sport Join Date: Apr 2008 Location: belgium iTrader: (0)	just from a physical point of view, between +25C and -5C air density increases by just over 11%. Air resistance is likely about 80% of power requirements under normal conditions, so 80% of 11% goes for sure in fuel economy. Next largest is power losses in tyre/road friction, and that is probably increasing a lot more with rain sleet, snow etc. And then we all use the seat heaters, the electrical grid heater will come in when coolant is still cold etc etc. So expect at least 10% worse fuel between summer and winter. In addition, in winter you have the complication of heating up some 600 lbs of metal in engine and transmission from sub zero to summer temps before you're equal to summer conditions. That will take some fuel too, and kill you on short distances.
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12-20-2009, 05:36 AM	#15
NFS Major General 296 Rep 9,218 Posts Drives: G80 M3 Join Date: Jul 2006 Location: UK iTrader: (0)	I drove a 330d for a week and got 32mpg. Mix of urban and motorways.
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12-20-2009, 06:43 AM	#16
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)	I think what F104 has said explains things. I only do short 10min drives most the time so the poor bugger never gets warm! I always put my heated seat on and the heaters on full whack! __________________ BMW E90 320D Sapphire Black, Angel Eyes, BMW Performance Extras, Carbon Fabric Trim
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12-20-2009, 11:11 AM	#19
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)	Indeed they are not just drove for two hours and I think she loved it __________________ BMW E90 320D Sapphire Black, Angel Eyes, BMW Performance Extras, Carbon Fabric Trim
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12-20-2009, 07:30 PM	#21
fuzzer123456 Enlisted Member 0 Rep 37 Posts Drives: 2012 118d M sport auto Join Date: Feb 2008 Location: Scotland iTrader: (0)	They change the diesel to stop it freezing in winter, remember the days gone by of lorry drivers building fires under their diesel tanks? well alas no more due to whatever they do to the fuel upside , doesnt freeze .. downside , less MPG. Mix that with cold weather , heater , heated rear window , heated seats , headlights and the engine not warming up and welcome to winter MPG mode.
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