Hi there. Just registered although I've been a proud Merc owner for 4 years!


Just looking for some advice on the following issue and some specific info on part numbers if possible. Thanks in advance!

I have a W211 E320 CDI '54 plate (648.961) and will admit from the start that I am not mechanically minded, so apologies if my descriptions sound a bit naive.

Firstly, last week I had a blown injector seal fixed which had resulted in the dreaded 'black death'. Mechanic said he think it must have been like that for at least a year - had the stench of fumes coming into the cabin for a couple of weeks.

When he tried to turn it over to bleed the injector, the car wouldn't start; we thought it was the battery so I hooked it up to a charger but found the battery was fine (this all happened on my driveway as he is a mobile mechanic). I say 'fine' but the battery is a little weak due to age/some electric gremlin somewhere as I get the 'Battery convenience features not available' for a minute or two if I don't use it regularly. It's always started fine though until this occasion.

Next day, the guy and his mate (who has a lot of experience with Mercs apparently) tried to work their magic on it but without luck. They ultimately decided that the high pressure fuel pump is a goner. The fuel pick-up pump was working fine, pressure into & out of the filter was fine etc. but the pressure out of the high pressure pump was too low to force air out and allow the engine to restart (the fuel was 'trickling out').

I should also add that over the last 8-12 months the car has felt under-powered and been reluctant to kick-down, and has on about half a dozen occasions, gone into what I would describe as limp-home when it will not rev over around 2000 rpm (thought without any warnings or alarms at all). On engine restart, all is fine.

I generally trust the mechanic but before I spend money on an HP pump, I just want to know if this all sounds consistent with a defective HP pump? It does to me, but like I said I don't really have a clue!


Second problem - I've searched the internet for the HP pump after being quoted £800 just for the part at Merc main dealer. The car just isn't worth that kind of outlay.

I've found plenty on Ebay etc but the part numbers are a nightmare and I'm worried about buying a pump that won't fit.

The Merc guy gave me the original part number, A646 070 0401, but they are difficult to source. There are far more with part numbers like A646 070 0101, A646 070 0301, A646 070 0401 etc.

On top of that, they have numbers, which I think are Bosch part numbers, like 0445010078, 0445010143.

I have no idea which will fit my car as they all say they do on one page but not on another.

The mechanic says the one on my car is a Lucas but I can't seem to find any of these which say it fits my car (LPD017 - some say it fits, others that it doesn't).

My question is then, can I fit a Bosch HP pump to my car if removing a Lucas?

And more importantly, does anyone have a list of compatible part numbers for my car and HP pumps?


This is driving me round the bend, or at least it would if I could get it started...

Sorry for the essay and thanks for reading - please help I'm getting desperate.

 

Codes, man. Post up the codes that have been thrown by the car both from the limp modes you've had and from the latest "no start" condition. Personally, I would question whether the HPFP is bad. The fuel holes in the rail are very small so even with the ridiculously high pressures involved there's only going to be a trickle of fuel pushed out. If fuel is being pushed out, there's fuel being moved. IMHO. How did they come to the conclusion that the high pressure pump is bad?
Get the codes and go from there. It will be a shame to replace an expensive part and still not be able to start the car.

 

You can't expect MB codes from Toro lawnmower mechanic.
So
1 get a mechanic with a scanner who can read MB codes.
2. read the codes or have them read'
3 post them here so we can try to make educated conclusion.