baker642

Looks to be the HPFP.

Thanks Greydog. Checked as you suggested, the return looks to run through the webasto unit, finally making a lot of sense. I can't perform many checks without the right tools to check pressure but I can hear the HPFP priming somewhat - I'm thinking it could be the sensor, injector wiring looks fine, I'll confirm in regards to the relay.

Is there anyway I can test the HPFP, opening a fuel line to the injectors?

Hi Greydog, Thanks for your knowledge on this system and the attached files really helpful. From your info, I can take away that the diesel pump has been checked and is working. I can also start to steer this to the webasto if there is a distribution valve linked to this unit, then this seems to be broken or forcing diesel only that way as no diesel is getting up to the injectors. Is the webasto fed diesel before or after the high pressure pump or not at all? Can I just unplug the webasto I've never used it? Do you know where the distribution valve is located, can view on the attached, but in the bay? Thanks for your help.

Hi all, Reporting back, it's definitely leaking from the webasto exhaust the on pictured. I don't really know enough about them but if say the high pressure fuel pump failed would the leftover diesel get routed through there and out the exhaust for example? As we know the pump under the rear seat is working and tested. Any thoughts? Thanks

Hi Dave, Thanks for the response. I did question the diagnostic equipment they were using but suggested the E53 didn't have a sensor to show up lack of fuel to the engine. I think it might be fuel filter as it's located underneath that area, I'm going to take the panel off tonight hopefully and get a better look, will report back.

Here's some pics I don't think this is the pre-heater exhaust but something around that area above the plastic?

Hey thanks for the welcome. The breakdown/recovery performed some diagnostic scans but unfortunately couldn't pick anything up. The fuel rail pressure was checked but not for a pressure reading, just to check if anything was coming through. Assume but only assume the MAF can be picked up on the diagnostic checks. I'm also thinking the high pressure fuel pump but any ideas of diesel leaking from the pre-heat exhaust?

Hi all, First post to the forum. I've had my E53 3.0 diesel just over a year now, no troubles at all. Over the weekend she started then lost power after driving 300 meters or so down the road. The car year is 2006 with 170,000 miles on the clock. From calling the breakdown out to check they couldn't find the issue, however on removing or loosening one of the injectors it's clear diesel wasn't being received up to the injectors. The following has been checked so far: - Battery good - Key/Immobiliser working - Fuel pump right hand side passenger is pumping on taking the rubber pipe off and turning the key (this is priming). - Noticed a puddle of diesel leaking from an exhaust on the left hand side underneath the car, slow drip. It's noted the car is cranking turning over but not starting due to lack of diesel. Ruled out fuel pump under right hand passenger side seat, where to go from here? Thanks in advance for your help/replies.