Help with a Problem Mercedes Please....

[roy c]

I have a Mercedes C220 (1997) diesel estate and we came back off holiday( we had left the car outside our garage for the 2 and a half weeks we were away) and the wife got in it and got down the road and it started coughing and belching out black smoke and wouldn't rev. It got her back home tho. I left it for a couple of hours then got in it started it and drove it for a couple of hours without a problem! I went to pick her up from work and it was fine for a while then the same symtons started again! This time it never cleared itself. We took it to our regular garage and was told that the diesel pump needed replacing!!! At a price of £1000 and 8 hours labour at a rate of £44 per hour. This we cant afford and I dont think the car is worth that much. So I am loking for a second opinion and do you think the garage maybe right or could it be something else? It was put on a diognostic computor and the pump came up as a fault... Thanks in advance...

 

[wotan]

Try the simple things first, does it have a mass flow air meter? if so try cleaning this first, also check the air filter.
That you say the fault cleared itself, only to re-appear again later, I would suspect the fault may be ECU related.
Take it to a different garage for a second opinion, before parting with a large wad of folding stuff.

Wotan

 

[heliosuk]

Firstly you need to look at the symptoms surrounding the issue. I take it, it was fine before the holiday?

For black smoke to appear would indicate over fueling. Then the fact it was left for 2.5 weeks standing. On a diesel, coughing and spluttering is a symptom of fuel starvation.

Again as a previous correspondant has said, check the air flow meter. There are two types and the one you need to look for has a flap in it. Clean out with carb spray but do not touch the insides. If there is no flap then loof further down the inlet route and there should be some sort of flap.

Make sure also that the engine vent valves are clean.

Firstly I'd change the filter and then fill with clean diesel. Tis possible it's picked up crap left in the tank so restricting the lift pump. This in turn would restrict the pressure pump which will over react in that it calls more fuel than can be delivered thus registering a fault. Apart from water sensors or pumps there is no way the system knows if the flow rate prior to the high pressure pump is enough to the best of my knowledge.

 

[redoctopus1]

This happened to our 3 litre Rodeo once but my wife had filled up in a town away from our home and picked up some dirty/watery fuel.
I would drain your tank and see what comes out then refill with a good known fuel.

 

[Mickymoody]

The diagnosis sounds correct, I had that in an Escort, prices excessive, only to be expected with a Merc. Black smoke, diesel pump fail, yes.

After pump replacement - fuel locks, stalls..make sure a good job is done,