XSeries-forum

My e70 40d was driving fine yesterday. The low fuel warning came on so I put £30 of diesel in and got about a mile and a half when it started to lose power as I was joining the motorway. I coasted to the hard shoulder and tried to start it...cranked but nothing.

I was eventually recovered and on looking at it today no faults showing on carly (other than the usual 4x4 and dsc).

I am suspecting possibly fuel but no more than a hunch. Anyone profficient in the use of carly as its all I have access to just now in checking any parameters without the car running.

Was considering removing the fuel filter which would appear to be under the car and checking for flow from the low pressure pump.

Had a search online but not much on this model

Probably fuel filter change required......it will crank for a while before starting as they are self priming no bleeding required.

Yes thats on the list...however would a fault code not show for fuel supply as I assume that would cause drop in rail pressure?

Had the thing on charge all day only to find out the charger is gubbed.

Not always and as you say you dont have any codes....when did it last have a fuel filter change should be changed every 40 to 50k depending on model.

Yes its worth a shot and I have never replaced it since purchase in Feb.

Am I right in saying the low pressure pump is under the floor on passenger side just the same as the e53 or is it in the tank. When changing the filter I may try checking for low pressure flow into a bucket.

You'll find all an how to do here:

https://www.newtis.info/

Are you sure it was diesel you put in as its a bit of a coincidence it stopping a mile after you filled up (just asking ! )

People always suspect the fuel filter but they don't just suddenly block so very unlikely to be the issue more like crank sensor or bad injector

Haha yes wrong fuel crossed my mind too. I checked the receipt and yes it was diesel.

I agree about the filter as these cars have plastic tanks sso the days of rust etc are gone. Surely a sensor fault would throw a code which would show up on a scan? Or would it?

The only thing I havent mentioned was that there was a long stretch of straight road with no cars in sight about 2 mins prior to breaking down. I floored the car on this stretch to observe the black smoke in the mirror but I cant think why this would cause this failure.

My concern is deciding which order to carry out diagnosis checks. That is why I am thinking check fuel delivery first but open to thoughts of the forum.

Undo the easiest diesel line you can find and crank it over and see if any fuel comes through......

Can Carly monitor the fuel pressure from the tank pump ? , I know with old software I could check the pressure of the underfloor pump in my old 330d , This pump failing would stop the car and they don't give much warning apart from the occasional loss of a bit of power/ hesitation before they go .

I did have a quick play with the carly app but to be honest I am not too familiar with it. I couldnt see any way of finding fuel pressure other than the rail pressure which showed 13000 kpa on cranking which is very low. That said I am hoping to hear from a forumite who knows their way around tha app to point me in the right direction as there is very little online for what appears to be a popular resource.

A BMW indy has come out and looked at the car and thinks the high pressure fuel pump has gone. He said that when these fail they normally break up sending metal fragments throughout the fuel system. I am looking at replacing the high pressure pump, pre supply pump and all six injectors. The tank will also have to come out and all fuel lines flushed....woke up this morning hoping it was just a nightmare...but no.

He said I should take the rear seat out and have a look in the fuel tank with a torch. Evidence of these metal fragments should be easily visible in the tank he said.

That lot sounds like enough to write the car off ! Hope you can get it sorted for a reasonable cost

To be honest I did consider it and thought of breaking it but just cant be doing with the hassle. The indy has said he will be £600 in labour and seems experienced with this issue. I am just trying to price the parts list which will be around two grand

Maybe you could get away without injectors , id do as he says and get a look in that tank first as 6 injectors is about 1500 quid and any further diesel will go though the filter before getting to the pump, surely thats what its there for but that's not so say the injectors are not damaged already .People have certainly changed the big pump on its own before but what the success rate is I dunno I guess to stand over it like Bmw its change it all ...