Leaking diesel pump panic!

[Rob77]

My 250 D (W124) has had a diesel leak from somewhere in the engine bay since as long as I've had the car (about 4 months). The obvious fixes, such as replacing the leak off hoses and injector seals didn't cure the problem but it never really worried me until now.

The car went in for its MOT today and I got a call, from the garage, to say that the diesel pump itself is leaking and needs fixing. I was told it would need to be sent to a specialist to be rebuilt and calibrated, and this would cost around £600.

After climbing down from the ceiling, I rang round some breakers but no joy there. Then I tried the motor factors and again none could help. However, Euro car parts tell me they can supply a brand new Bosch diesel fuel pump for £119.99 + VAT (this is not even exchange, its actually a new fuel pump).

I've read through the other posts on the subject and the rebuild is often mentioned and the estimate I was given seems about right for a really knackered pump. But does it seem likely that the new part I was quoted for will be the replacement I need? It just seems weird that I can buy a new part for a fraction of the cost of rebuilding the old one.

I'd be very grateful for any advise here. The rebuild cost is what the car cost me and I'd like to avoid spending it if at all possible. Everywhere is closed now, until Wednesday, due to the New Year holiday but I need to get something organised for then so I can drive again.

 

[Parrot of Doom]

Fuel pump or injector pump? I suspect its the latter you need, which could be the more expensive one.

 

[Rob77]

When I spoke to the supplier, he asked if it was a vaccuum pump or a fuel pump I needed and when I checked with the MOT station they said fuel pump, not vaccuum.

Is a vaccuum pump the same as an injector pump or is this a third thing? If its the same, then I could get the vaccuum pump for £138.60 (plus VAT and 4 hours labour)

 

[Parrot of Doom]

You need the MOT station to tell you what part number they're talking about, and where it is located on the car.

I've had a look on the software I have, unfortunately it doesn't list your engine type so I can't check.

 

[Rob77]

Thanks for the replies. Everywhere's closed now until Wednesday so I'll have to check out the part number then.

I didn't realise the car would have any more than one diesel pump. And in the meantime, if anyone has any further ideas, I'm all ears.

 

[twice]

Hi,

I had a fuel leak on the injection pump on the top where the high pressure line leave the body. There are rubber O ring to be changed under the high pessure valves, easy job to with app. 2 hours labor . Mine have been changed for 20GPB by an indy in Hungary.

I was told that this is a common problem.

I have an other leak on the side of the this pump, from the black plastic switch. I will be visiting my indy for O ring change as well. If it will not solve the problem, then the switch (90GBP) needs to be changed. I hope for the O rings.

Regards,
Attila

 

[Dieselman]

I suspect ECP have quoted for the wrong part, I would be amazed if you could get a new diesel pump for anything like the money you have mentioned.

The fuel pump has a leak but is perfectly servicable so why are you thinking of changing the pump?

Either trace the leak by drying off and running the engine or have a diesel specialist look at the pump.

As has been mentioned the seals are very cheap and there shouldn't be any need to callibrate the pump just for new seals, and it may not even need to come off the car depending on where the leak is from.

 

[Dieselman]

I didn't realise the car would have any more than one diesel pump. And in the meantime, if anyone has any further ideas, I'm all ears.

It doesn't.
Well not strictly true but they are together as one unit, although spares could be bought seperately.
You have the main high pressure pump with the low pressure lift pump on the side of it.

The low pressure pump sucks fuel from the tank and pressurises to 25psi, then the high pressure pump pressurises it to about 4350 psi.

There is nothing complicated about a PE in-line pump. The fuel is fed into a common gallery and drawn into each cylinder (5 off). The piston then pressurises the fuel until the pressure exceeds the injector break pressure, at which point the fuel sprays.

Assuming the body of the pump isn't cracked (it won't be) then you just need a seal.

 

[Rob77]

Hi Dieselman, I knew there was a leak as it smelled badly of diesel and you could see the fluid but it started fine and didn't seem unecconomic to run so never really worried.

It was the garage doing the MOT that phoned to say the pump was leaking. They were busy because it of the holidays so may not have looked that close. All he said was that the last time they experienced that problem it was sent off (to someone like Lucas, I think) and it cost around £600 to rebuild and calibrate then 4 hours labour to remove and fit.

The guy knows I can usually find parts at a good price so he was letting me know so I could maybe come up with a cheaper alternative. Unfortunately, I know nothing whatsoever about pumps.

It sounds like my garage doesn't have a lot of experience with these either so for the MOT, it sounds like it'll have to come off the car, either to be replaced or overhauled in some way.

I was hoping the new part at £119.99 was the answer but I'll have to wait to get the part numbers checked for that. If I get it removed, is there a decent place I could send it for resealing that wouldn't cost the earth? I'm assuming at this strage that it isn't cracked or anything.

And under what circumstances would recalibration be required?

 

[Dieselman]

As the car starts Ok I would think that the leak is either on the high pressure outlet valves or the return pipe on the engine side of the pump.

I doubt the pump needs to be removed at all, unless the seal on the drive shaft is leaking (unlikely).

The pump would only need setting up if it was fully stripped, which it shouldn't need for this problem.

Any competant deisel repair specialist will be able to do this job.

Hmm I can only find one on Yell.com, there must be more than this.
There are several in Glasgow.

Lawson Diesel Injection Ltd
72, Newhaven Rd, Edinburgh, Midlothian EH6 5QG
Tel: 0131 555 1950 Classification: Diesel Fuel Injection

If you have the car at home dry around the pump then run the engine and check for wetness both visually and by using toilet roll or similar.
My money says it's the high pressure output valve seals leaking. No need to remove the pump for these as they are right on top of the pump body.

If the pump was truly knackered (it isn't, the car runs too well) then the engine oil would be rising and would smell of diesel due to internal leakage in the pump.

The timing of these pumps is due to it's position on the engine so if removing it remember to mark the position with a scribe mark.

 

[Rob77]

Thanks again Dieselman, you've been a big help. Unfortunately, the car's still at the garage so I can't do the checks you mentioned until Wednesday. It went in for its MOT and this is a job that needs doing in order to pass.

It sounds like the most practical plan would be for the garage to remove the pump (marking it first) then I can pick it up and take it around to the diesel specialist to have the seals replaced before the garage refits it (to the old marks). Presumably, the specialist would have the necessary seals and I wouldn't need to go to a Merc. dealer for those too. I'm guessing this might cost £100 - 150, which would be great.

I'll also check the part numbers first, just in case the ECP price is actually for the correct unit. It really doesn't seem likely but it would be the quickest and easiest solution if it is.

Fingers crossed then and all the best for the new year

 

[Dieselman]

Speak to the diesel specialist before doing anything.

Removing the pump from the car is what will cost the money in labour so see if you can get them to look at the pump in the car. If necessary pay the garage to drive the car to the diesel specialist.

 

[Rob77]

Speak to the diesel specialist before doing anything.

Removing the pump from the car is what will cost the money in labour so see if you can get them to look at the pump in the car. If necessary pay the garage to drive the car to the diesel specialist.

Good advice. I'll do that and let you know how it goes. Thanks again.