[acerboo]

have noticed an increase in fuel consumption recently, mpg dropping from 35 to 32 on short journeys, wondering if the cold weather is contributing to this as the engine seems to take a lot longer to get to operating temp

[jimmylad]

same here but 99% of the time its down to the cold weather although it's a lot milder than it has been. Is the 32mpg an overall mpg over 1000's of miles or just a reset every fill up ??

When Simon re - remapped my 335d on xmas eve last year it was minus 10 degs outside his house & we went for a 10 mile run & the car was only up to about 80 degs after the test run. The car hasn't got a problem as I often hook my laptop up to monitor the water temp ( gets to 90 in normal weather )

These cars don't run at peak effieciency until they get warmed up (gear box slugish etc) & this probably applies to any diesels but I have had 53mpg from mine on a 200 mile trip @ 55/60 & resetting the journey computer to do the 5 mile school run can return a feeble 27 ( heavy traffic / snow etc) with a high of 40mpg in optimal conditions.

32 on short journeys is actually not that bad overall & the 3mpg drop is 10% which is what to expect from cold weather.

Going to start a thread on tips for economical driving. One day..........................

[milesr3]

Don't know whether the E9x are anything like E6x but I've just had a right ordeal getting my 535d running at the right temperature. It makes a massive difference to fuel economy and driveability. Mine starts doing very frequent (300 mile apart) DPF regens if it's not hitting 90C on a run and regenerating passively. Presumebly it's producing a lot more soot if combustion if inefficient.

Mine has had a new main 'stat and gearbox heat exchanger 'stats done by the dealer but it was still hovering around 78C even when fully warmed up and taking much much longer to get there. They tried to tell me this was perfectly normal, but then all of a sudden it started running at 90C again and it felt like I had my old car back again. Then this week it went back to intermittently losing all coolant temperature after warming up again.

Whatever the car and ambient temperature, they should be running around a couple of degrees above and never below the main 'stat rating, which is 86C in mine.

Despite what BMW thought, I just changed the EGR thermostat today as it's the easiest/cheapest one to do and is most often recommended on BMWLand. Sure enough the old one was stuck open and must have been allowing just enough coolant to circulate round the main 'stat so that it wasn't regulating the coolant temperature (mine varied between 67C and 91C on a long run). Mine is now pegged to 90C again and the difference it makes to throttle response is remarkable, which enables you to drive it much more efficiently. Not to mention being more torquey simply from burning all the fuel being injected.

When running at 90C I've had 47mpg on Fuelsave diesel from mine over a 160 mile trip whilst still nudging 80mph whenever possible, so these cars can be remarkably economical when operating at their optimum temperatures.

[milesr3]

Seems that you do have the same offending part (#8) on a 335d according to realoem:

[briers]

Other cars have been affected by the weather but my 335d doesn't seem to change that much.

I haven't noticed much change in fuel consumption. It's always around 42mpg to the tank, sometimes 40.

As for temp's, i checked it on friday and it was 93C which dropped to around 87 as i took it easy before parking it in the garage for the weekend. But frequently i see around 86 as my average when warm.

[wayne71]

Jimmylad how do you hook a laptop up? What program do you use etc?

[rsmallwo]

how do you check your temp? anyway of doing it without a laptop....

Why oh why there is no temp indicator I don't know

[jimmylad]

well ...................... i bought a cable n software off ebay. the cable plugs into the connection that is hidden behind a small flap type thing in the drivers footwell near the bonnet pull. Looks like a scart socket.

Software is edibas ( spelling ?? cant check at the mo as it's on my other laptop) just select model & engine & it tells you all sorts about you car / fault codes.

Got tis, dis & sss but not had any luck with tis & sss connecting yet.

[jimmylad]

Originally Posted by milesr3

Don't know whether the E9x are anything like E6x but I've just had a right ordeal getting my 535d running at the right temperature. It makes a massive difference to fuel economy and driveability. Mine starts doing very frequent (300 mile apart) DPF regens if it's not hitting 90C on a run and regenerating passively. Presumebly it's producing a lot more soot if combustion if inefficient.

Mine has had a new main 'stat and gearbox heat exchanger 'stats done by the dealer but it was still hovering around 78C even when fully warmed up and taking much much longer to get there. They tried to tell me this was perfectly normal, but then all of a sudden it started running at 90C again and it felt like I had my old car back again. Then this week it went back to intermittently losing all coolant temperature after warming up again.

Whatever the car and ambient temperature, they should be running around a couple of degrees above and never below the main 'stat rating, which is 86C in mine.

Despite what BMW thought, I just changed the EGR thermostat today as it's the easiest/cheapest one to do and is most often recommended on BMWLand. Sure enough the old one was stuck open and must have been allowing just enough coolant to circulate round the main 'stat so that it wasn't regulating the coolant temperature (mine varied between 67C and 91C on a long run). Mine is now pegged to 90C again and the difference it makes to throttle response is remarkable, which enables you to drive it much more efficiently. Not to mention being more torquey simply from burning all the fuel being injected.

When running at 90C I've had 47mpg on Fuelsave diesel from mine over a 160 mile trip whilst still nudging 80mph whenever possible, so these cars can be remarkably economical when operating at their optimum temperatures.

how much & how easy was it to change the egr stat ??

[acerboo]

the mpg was reset after filling up (had to get a loan from the bank to do that!) its now dropped to 31 dont know how much lower it will go. mine runs consistently at 86 degrees but i live up a very steep hill and in the summer it sometimes rockets to nearly a 100 but, not always, its pretty inconsistent. the most ive seen is 45mpog for a brief period on a long run. mines a 2007. dont remember such an increase in consumption in previous winters.

[acerboo]

Originally Posted by jimmylad

well ...................... i bought a cable n software off ebay. the cable plugs into the connection that is hidden behind a small flap type thing in the drivers footwell near the bonnet pull. Looks like a scart socket.

Software is edibas ( spelling ?? cant check at the mo as it's on my other laptop) just select model & engine & it tells you all sorts about you car / fault codes.

Got tis, dis & sss but not had any luck with tis & sss connecting yet.

can you say where on ebay you got the cable, thanks

[Ti Rich]

Very , Very interesting!!! You don't need a laptop to access the coolant temperature, see http://e90.wetpaint.com/page/BC+hidden+menus


Today i used the hidden menus on a 60 mile each way trip. On the way there (motorway, 70mph) coolant stuck at 72-73C. Way back, same speed 86-87C.

Any ideas?

[briers]

I'd be interested into a EGR thermostat guide too.

As for checking the coolant temp

- press and hold the trip stalk (which is on the speedo) for 10 seconds
- you will now see a menu e.g. 01.00
- below this is something like FNSR1234
-add up the numbers e.g. 10 for the above example
-using the trip button navigate to menu 19 which will say LOCK, wait 2 seconds until it says lock code
- using the button navigate to the number that matches you calculated number e.g. 10
- it will then say something like LOCK OFF and i think it goes back to menu 01.00
- now using the button navigate to menu 07.00 (that is your coolant temp).

There is a thread somewhere about this in more detail.

If you end up in 01.01 / 01.02 (the sub menus) then press and hold the trip button for 2 seconds to go back to the top level menu e.g. 01.00, then you can continue navigating to 07.00.


//edit, beaten to it, link in post above

[wayne71]

Originally Posted by jimmylad

well ...................... i bought a cable n software off ebay. the cable plugs into the connection that is hidden behind a small flap type thing in the drivers footwell near the bonnet pull. Looks like a scart socket.

Software is edibas ( spelling ?? cant check at the mo as it's on my other laptop) just select model & engine & it tells you all sorts about you car / fault codes.

Got tis, dis & sss but not had any luck with tis & sss connecting yet.

Ah right cheers, that is the obd socket which I hooked my evolve switch upto, if you get chance could you confirm what software it is you used on your laptop?

Cheers

[HighlandPete]

Not uncommon to have up to a 10% drop in economy during winter driving. That is without any coolant temperature issues. Slower warm up times plus extra parasitic losses.

Try resetting the OBC and make a run of say 5 miles on a cold engine, compared to the same run with a hot engine. The consumption difference can be halved on the cold engine, starting from sub zero temperatures.

HighlandPete

[jimmylad]

used this guy ( nice guy too) http://myworld.ebay.co.uk/bmwteq/

when I was having problems with my car starting I wanted somthing to read my fault codes. As he didn't live that far from me he said i could visit him & he would install it on my laptop ( one of them)

his laptop plugged straight in & read all sorts of codes even telling me when a bulb even blown. Took my laptop into his house & he installed all the software apart from one software (sss I think) & he said I should do it when I get home as it was a 23GB file & would take ages to install. I installed it at home but couldn't get it to run but then my car went in to various garages to sort problem ( new ecu in the end) so I was car less for 2 weeks & haven't worried about getting dis & sss to run although I could ask him to remote view my laptop & he would sort it but I just havent got round to it.

[milesr3]

Originally Posted by jimmylad

how much & how easy was it to change the egr stat ??

The part was £33 including a new o-ring and it took me about 1/2hr taking my time. It's very accessible right in-front of you when you open the bonnet and only held on by a couple of screws and a jubilee clip. On my 535d I also disconnected a vacuum line to get better access to the rear screw and not break anything. Have a look as it may be slightly different on the E9x.

Do check your heat-soaked temperatures first though via the hidden menu on the dash.

[Dr Dave]

Hmmmm very interesting info! Will try to access this temp info on mine......

[milesr3]

Originally Posted by Ti Rich

Today i used the hidden menus on a 60 mile each way trip. On the way there (motorway, 70mph) coolant stuck at 72-73C. Way back, same speed 86-87C.

Any ideas?

This is EXACTLY what mine was doing. One day it would sit at 90C +/- 1C for 180 miles, another day vary between 70-83C over the same distance and more recently get up to 90C and then suddenly lose all coolant temperature and drop to the upper 60s after an hour of driving.

86-87C will be running regulated by the main 'stat. 72-73C will be the EGR 'stat allowing enough coolant to circulate round the closed main 'stat that it isn't regulating the coolant temperature in the current ambients.

Take the EGR 'stat off when cold and if you can blow through it easily, it's buggered.

[Ti Rich]

Originally Posted by milesr3

This is EXACTLY what mine was doing. One day it would sit at 90C +/- 1C for 180 miles, another day vary between 70-83C over the same distance and more recently get up to 90C and then suddenly lose all coolant temperature and drop to the upper 60s after an hour of driving.

86-87C will be running regulated by the main 'stat. 72-73C will be the EGR 'stat allowing enough coolant to circulate round the closed main 'stat that it isn't regulating the coolant temperature in the current ambients.

Take the EGR 'stat off when cold and if you can blow through it easily, it's buggered.

Thanks for that, will check it out! - Do you need to drain the coolant system to fit it? Any chance of a guide!!!

Going to change airfilter next week and check/Clean EGR valve. This would be an ideal time to do this.

[milesr3]

No need to drain the coolant. The EGR stat is at the highest part of the system and the coolant drained back down into the system as soon as I loosened the hose rather than spilling out of mine. The stat has a bleed screw in the top as well so you can bleed any trapped air back out again once refitted with the engine running.

Fitting is very straightforward. I removed the engine cover and moved a vacuum pipe out of the way of the rear screw by undoing it and pulling it out of the vacuum pump (torx head screw). The 'stat is held on to the EGR cooler by two screws and a jubilee clip round a hose at the other end. I undid the hose first to try and catch any coolant that might have come out, but none did. Put it all back in the reverse order as you took it off :-)

[F31-340i]

Originally Posted by milesr3

Seems that you do have the same offending part (#8) on a 335d according to realoem:

Interesting thread - I must check the temps next time on a run.

Looks like the same part is on a 330d too.

(this link has exactly the same 263.png image)

http://www.realoem.com/bmw/showparts...97&hg=11&fg=50

Looking at Dr Daves Air Filter how to http://www.e90post.com/forums/showth...30d+air+filter

...it appears the EGR thermostat is the black object at the front of the engine block with a small round cap with a cross on it...



...looks like access to the rear securing bolt is made a bit tricky by a pipe - as mentioned by miles