[jinjur]

Mega,

Did you get any of the work done or at least some feedback from the dealers?

Regards
Andy

[SteveF1]

Mine was back in at Bowker Preston to get a second opinion after BMW Rochdale admitted that the 34mpg they averaged was low but they couldn't fault anything and therefore couldn't help me. Bowker pretty much did the same thing, sent it out on numerous tests, came back, checked the dianostics and no faults. They stated the MAF, fuel pumps, fuel injectors were all in great condition but they were hard pressed to do anything more because under the warranty rules if there is no fault (and thus a code) they cannot start taking parts off and replacing things as BMW won't authorise it.

They returned 31mpg as an average and thought this was generally in line with what their reps were getting in comparable company cars.

All in all they had it four days and nothing was resolved. Suffice to say it still drinks juice like a V6 but has none of the performance to go with it.

I'm gonna have to live with it or sell up.

[Jeff123]

Hi

This 31 MPG stuff is complete cobblers.

Mine is an auto. I travelled down the A1(M) yesterday and an 82 mile trip got me 56 MPG - admittedly, some of the trip was restriced to 50 MPH and I drove very steadily. The car has done 30,000 miles and only has had an oil change in this time, so I guess the plugs etc are still the originals??

Jeff

[jinjur]

Thats disheartening Steve

Of all the people to sort this terrible economy out, I had high hopes that BMW tech would.

How on earth will a wee monkey with an old, unwarrantied motor like me get anywhere?

JJ

[MEGA]

I got nowhere. They got no fault code out of the system and thus blindly refused to replace the air filter or glow plugs, even though they'd previously agreed to do this over the phone and face to face before I booked it in.

Averaged 26 since having the car back.

[F104]

as you did about everything, and are not anywhere close to mileage others and myself are getting I would look at this. How to resolve any issues found is the next questions:

remove the intercooler pipe from the engine inlet (push it in, pull circlip up, and it releases). Disconnect air inlet temp sensor and then you have some room to pull the pipe up. Expect to see film of fairly clean oil on the throttle valve, and/or a drop coming out.

If you see loads of (black) oil I would be temped to remove the hose from the intercooler as well and check if oil is in your intercooler and effectively partially blocking it

on the throttle valve gently push on it to rotate it open against the gearing of the electric motor. It will be a one black mess on the back of the plate and inside, but question is how much. It should be only coated, not a 1/2" layer of the stuff. Behind the throttle plate you can see the EGR pipe.

to check the inside i suggest you take pictures with a digital camera with flash

[SteveF1]

The dealers are bound by BMW rules which are restrictive and completely illogical.

As stated the dealers stick the car on the diagnostic computers and check everything as per the data supplied by BMW. If its within certain tolerances and there are no faults being thrown back then they do absolutely nothing physically with the car. I had a slanging match with the service manager telling them they rely too much on the diagnostic results and that in years gone by things would be taken apart and physically checked. He reminded me it was the 21st century and that none of that was necessary and that the computers told them everything they needed to know. I aksed him about a build up of crap in the combustion system - he pretty much replied 'the computer says no'. This is what I got to every question and query Iposed and they refused to touch the car unless there was a fault as they don't get paid by BMW otherwise.

It was four days of banging my head against a wall with daily updates from BMW telling me the test showed no problems. I persisted and asked them to check it again with the same reply back. I've been to two dealers (not part of the same group) and they both came back with the same result so I've admitted defeat.

The cars up for an oil service soon so I'm gonna put some nice Silkolene oil in, change the oil and air filters and see what happens. This might be my best bet.

[MEGA]

You'll need to replace the air filter yourself. BMW will refuse to do it unless the computer says so

[nik_nak]

Blimey I get 36mpg from my 330d, and that is mostly round town.

Originally Posted by MEGA

Averaged 26 since having the car back.

[SteveF1]

Since the car came back I've filled her to the brim with BP Ultimate diesel, see how she goes. I've had her on Shell V Power for the past three fills and although I noticed things running smoother and slightly more 'perky' there was absolutely no difference with the consumption. A lot of people say the BP stuff might prove a better bet in the consumption area so I'll see if they're right.

[jinjur]

Tried that myself chap and while I will absolutely agree with the fact that the car seems to run alot smoother......I noted absolutely no difference in economy.

And that was driving big motorway miles across Scottyland.

Andy

[gavp]

Interesting read this thread, seems when they are bad they are very very bad.

Had an 04 330d from new and was disappointed at the 35mpg over 42,000 miles I covered.
It needed 6 new injectors and a starter motor about 6 weeks before the warranty ran out. Local (non supply) dealer changed these without question.

Since March have an E91 320i LCI, averaged 37mpg over the 3000 miles so far!

E46 M3 (when its used) averages 28mpg

[jinjur]

Both interesting and depressing at the same time mate....



Andy

[DeeMac]

I have a Jan 2006 E91 320d with 65k miles, full BMW service history, and was getting 29-31mpg in winter and 34-38mpg in summer. I mostly drive in town. It was mapped by DMS Dec 08, and that slightly improved mpg.

To improve mpg Bavarian suggested changing how I drive. Change up between 1500 and 2000rpm, coast along on torque and don't rev engine. If I do this on a long run (M1/A1, avoiding stop/start traffic) it goes up to 44mpg. Go into town and it drops below 39mpg. Getting 500 miles per tank which is better than previous petrol car but not blown away by economy.

I towed a caravan to cornwall and still got 400 miles on a tank.

I think an auto with a larger engine will match what I currently get so will consider that for next car.

I drove a 177bhp 520d and it got 48mpg on M1, dropping to 39mpg once I went into town.

Long story short, I think it depends on where and how you drive.

[jinjur]

Points noted Dee.......i agree that driving style and route massively affects the economy.

But i also hadve to say and i know i said this a few times already, I borrowed the father in laws Accord 2.2 Derv for a wee and on exactly the same route with exactly the same driving style, we saw 48 mpg, tank measured.

With regards to performance, very little if anything in it.

I have also noted a very lacklustre kind of response from Bavarian.

A

[SteveF1]

While my car was in the dealers so they could check the consumption I was handed a 318 petrol loan car for a week. I averaged 33mpg with that car driving the same route but driving it like a loan car should be driven if you get my drift. Thats generally 2mpg more than I get on my own motor which tells you lot.

As I stated previously, I just hope the oil and filter changes make a big difference.

[jinjur]

To be honest mate......i really cant see it making much of a difference in economy.

Did you every get any injector related tests done Steve?

A

[Ti Rich]

Has anyone with MPG problems actually replaced the MAF yet?

Also i would remove the EGR valve and clean it, costs nothing to do but is a messy job!

[MEGA]

BMW have so far refused to replace this item even though I believe it will help considerably.

[jinjur]

Surely, the test for a sick MAF is pulling it and noting differences? i.e. there were none.

I think we have all done that already.

And as for my EGR.......I swear it has to be the cleanest on earth.

Seriously.


Andy

[SteveF1]

Did you every get any injector related tests done Steve

Yeah, BMW said the fuel injectors were clear and the amount of fuel being pumped through was spot on, ie no blockages and not over supply and excess burning of fuel.

As for BMW taking things out and doing manual checks - forget it! They don't touch anything without a fault code so despite me suggesting MAF sensor, fuel injectors etc neither of them was physically checked or removed to see if it was faulty, the diagnostic said they were fine and that was that.

[mato]

Lots of short trips here n there kill the economy with diesels mate, they take alot longer than petrols to get up to runnig temp , im averaging 27-30 at the mo , e90 320d lots of short trips picking kids up ect , probably less than 2-3 miles at a time. But when i go on a run get 45mpg ,

im happy with what im getting , i had a e34 520 and e39 523 both petrol autos and never got over 20mpg !!!

Had a e36 M3 evo and averaged 16mpg