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wont start <diesel>

Posted: Sat Jun 23, 2012 5:55 pm
by 610kev
hi , i have been out in the x5 this morning started without any probs .then went to do some shopping came back and it wont start .the rac came to look at it and he thinks it could be the fuel pump, should be getting 300bar but only getting 6/7 bar so he says its the pump .anyone with any other thoughts and what to check  thanks kev

Re: wont start <diesel>

Posted: Sat Jun 23, 2012 6:18 pm
by X5Sport
It just might be the fuel pump relay which is located above the glovebox.  £10 component and a common ish problem.  Fuel pressure to the main fuel filter head is only around 3.5 - 5 bar.  It's the fuel rail pressure you really need to know.  Had the relay go on mine and the pump was fine.

See thread here.  Or do a search on fuel pump relay and see if there are any similarities with what others have had on here... :)

Relay position above glovebox.  Item 01.

Other options might include the fuel pre-pump which is under the car.....passenger side rear I think?

Re: wont start <diesel>

Posted: Sun Jun 24, 2012 5:18 am
by Turks
I had something like this happen to me in my 530d. It was the High Pressure Fuel Pump (HPFP). The only difference in my symptoms that it was a gradual thing and not sudden like yours. I would be driving along and power would just go, or it would idle really rough. In the end I pulled up my GF's drive and then it wouldn't start again. GF's dad is a great mechanic and he showed me what the pump was doing in the workshop - we replaced it and all was good again!

Hopefully for you it is something a little cheaper like the relay mentioned.


Turks.

Re: wont start <diesel>

Posted: Sun Jun 24, 2012 4:38 pm
by 610kev
i have removed the back seat and the cover plate .i have been told  to turn on ignition  and place a screw driver on the pump and listen for vibrations through the driver .this i have done and can hear both pumps working hope this makes sense .so couild it be the relay etc etc  .........kev

Re: wont start <diesel>

Posted: Sun Jun 24, 2012 4:52 pm
by X5Sport
Have you checked whether this fuel pump under the car is running too?

Re: wont start <diesel>

Posted: Sun Jun 24, 2012 5:00 pm
by 610kev
hi ,  no i have not checked this yet