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BMW X5 e70 bad mpg 2007 30d

Posted: Wed Jul 24, 2019 8:27 pm
by Ryanleady
Can anyone help I am only getting 16.5 mpg out off my 3.0d and I am driving it normal not dring it hard I read up I should be getting at least 20 to 25 mpg around town Does anyone have any ideas what it could be or what I can change it has just had a service by the garage I got it from they did only do diesel filter, oil filter and oil change

Re: BMW X5 e70 bad mpg 2007 30d

Posted: Wed Jul 24, 2019 8:59 pm
by X5Sport
Could be a number of things but the first thing to get done is a code read of the error logs to see if anything shows up. It is worth getting this done either by BMW (it takes about an hour) or somewhere that can properly identify the error codes. Getting ‘generic’ codes (as would be done by a non-specific garage won’t be a huge amount of use.

It could be a blocked Diesel Particulate Filter (DPF), injectors, turbo, engine map played with, EGR valve sooted up, the list goes on and gets expensive, hence the suggestion about a code read.

I would expect better than 25mpg around town too. Diesels will soot up if only used on short journeys as they prevent the DPF from fully warming up. Failed glowplugs also prevent the regeneration cycle which burns off the soot. The engine needs to be fully warmed up and the car driven at above 40mph or 2,000rpm for at least 20 minutes. The exhaust hits about 800°C and needs glowplugs to drive the temperature high enough to do the regen.

A member local to you with a diagnostic system may be able to offer help.

And you only need to put the issue in one thread, not three. :)

Re: BMW X5 e70 bad mpg 2007 30d

Posted: Wed Jul 24, 2019 9:21 pm
by Ryanleady
I have plugged it in myself it come up with glow plug 1 3 and 6 but got told that won’t be the problem as they are just to start the car really because it the same the when engine is warm

Re: BMW X5 e70 bad mpg 2007 30d

Posted: Wed Jul 24, 2019 9:41 pm
by StuBeeDoo
Ryanleady wrote: Wed Jul 24, 2019 9:21 pmthey are just to start the car really
That's not the case with modern diesels.

Re: BMW X5 e70 bad mpg 2007 30d

Posted: Wed Jul 24, 2019 10:03 pm
by X5Sport
Even one faulty plug will prevent a DPF regen, although some owners have had differing messages. I had two fail on my X6 and there were no regens. My Indy told me it stops it as did my BMW Dealer and judging by the amount of smoke that emerged when both they and the control unit were changed earlier in the year, I believe them. The world behind vanished when the first regen happened.

You can diy but be very very careful. The plugs on these engines were not fitted with a ceramic grease at new and tend to ‘grow’ into the head, if you are diy’ing then lubricate them at least a week ahead of planned replacement, and keep doing it.

Even with an expert doing mine several snapped and it cost me £800 for 6 new plugs and a controller - significantly cheaper than a BMW Dealer - by the time the head was helicoiled and fixed (it didn’t have to come off as there are helicoiling repair kits now made that make that unnecessary).

If you have three bad plugs then change the controller (Beru make it) as well. But that sounds like your issue, a blocked DPF. Has the light been tampered with to keep it from showing?

Re: BMW X5 e70 bad mpg 2007 30d

Posted: Wed Jul 24, 2019 11:14 pm
by Ryanleady
No nothing been tampered with I am getting no smoke or signs of being in limp mode just very poor mpg

Re: BMW X5 e70 bad mpg 2007 30d

Posted: Wed Jul 24, 2019 11:35 pm
by Leslie
Are the tailpipes black as they should be clean and black is a sure sign the dpf is not working , 1 got 30 mpg in my e70sd over 210 miles today towing a 3/4 ton trailer but it was almost continuous driving and a lot of dual carriageway , mixed driving is 25 to 27 mpg , round town only with lots of very short runs you could easily see 16 mpg !
Its almost impossible to get an average of 30 mpg over a tank on these if you exceed 60 mph no matter how light your foot is despite the 34 mpg bmw claimed :driving: , The 2 thermostats are a common failing and costs a few mpg too, you can check in the hidden menu (see youtube) to see if it heats up to 88c , mine didn't exceed around 70 before I changed them.