'98 W202 C250 TD conked out on the M25

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neilrr

MB Enthusiast
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Yesterday I drove about 60 miles on motorways, stopped for 20 minutes & headed back only for the car to just lose power & stall a couple of miles after getting on the M25. Cruising along at about 65 in the LH lane, no funny noises, no warning lights, just no power & the engine died.

It's been running on brand new SVO with about 10% petrol for the last thousand miles or so without any problems. I had a new fuel filter so fitted that at the side of the m'way & added 5 litres of diesel I keep in the boot all to no avail. Examined the pre-filter & it looked almost new with only a few bits at the bottom & +95% of the mesh clean. The oil coming out of the large old fuel filter was crystal clear & clean. Pretty much flattened the huge (newish) battery trying to get out of there & in the end called a recovery guy I know.

Battery recharging overnight & I'm ready to try to get to the bottom of this.

Where do I start please?
 
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Running on SVO...You mean cooking oil off the supermarket shelf? f so then I would hazard a guess that you may have done your pump or pump seals in. You should be mixing in a 50/50 mix of SVO & Diesel rather than mainly SVO which has glycerine and can cause massive problems which is pretty much what you are experiencing.
Try draining the SVO out of the tank and replace with diesel and additive and flush it through the system.

Keith
 
Generally the only thing that stops them running is a fueling issue. The advice above is spot on.
 
Running on SVO...You mean cooking oil off the supermarket shelf? If so then I would hazard a guess that you may have done your pump or pump seals in. You should be mixing in a 50/50 mix of SVO & Diesel rather than mainly SVO which has glycerine and can cause massive problems which is pretty much what you are experiencing.
Try draining the SVO out of the tank and replace with diesel and additive and flush it through the system.

Keith

Thanks for the input but what you are saying is the opposite of what many others have said, including people who have owned & driven these things 10s of thousands of miles on SVO or WVO.
http://www.mbclub.co.uk/forums/general-discussion/123023-w202-c250-dt-any-good.html
 
what i would do is this:

- check for the oring seals on all the clear pipes
- remove and clean out the in-tank strainer

it will take a while to crank the car, especially if its now cold veg in it. a good tip to lessen the strain on the battery when priming the system by cranking is to disconnect the glow plug relay power so that the battery doesnt flatten so quickly by heating up the glows when it has no chance of starting anyway as there is no fuel pumped up yet. when it starts to grumble, reconnect.

if you have no luck with that, then disconnect the feed rubber pipe from the main metal feed pipe from the tank in the engine bay and put it into a bottle of fuel, then crank from there - if it starts you know its a blockage from the tank end of the system.... probably the in-tank strainer, otherwise blockage in the pipes. you could also swap the feed/return pipes around.

after 1000 miles approx the filters often clog when 1st running on veg as it cleans all the rubbish of the side of the tank and it gets stuck in the in-tank strainer and the pre-filter (which i believe you've already cleaned out).

get an assistant also to check the clear pipes to see if fuel is working its way around the clear pipes as you crank.

how much fuel is showing on the fuel guage? 1/4 tank???
good luck

Derek
 
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Thanks for the input but what you are saying is the opposite of what many others have said, including people who have owned & driven these things 10s of thousands of miles on SVO or WVO.
http://www.mbclub.co.uk/forums/general-discussion/123023-w202-c250-dt-any-good.html


My advice is based on 14 years of running a 2.8TD Mitsubishi Delica L400 and a 4x4 Club with many member having the same problem...so its 1st hand knowledge. I have seen MANY cars go in the fashion I have stated. Below, 2 pix showing damage to 2 different engines, one being a Toyota Land Cruiser, caused by using SVO & WVO. Hope you get it sorted whatever the problem.

Keith

IPafterbeingrunonWVOshowingpolymerisation.jpg
WVO1.jpg
 
what i would do is this:

- check for the oring seals on all the clear pipes
- remove and clean out the in-tank strainer


it will take a while to crank the car, especially if its now cold veg in it. a good tip to lessen the strain on the battery when priming the system by cranking is to disconnect the glow plug relay power so that the battery doesnt flatten so quickly by heating up the glows when it has no chance of starting anyway as there is no fuel pumped up yet. when it starts to grumble, reconnect.

if you have no luck with that, then disconnect the feed rubber pipe from the main metal feed pipe from the tank in the engine bay and put it into a bottle of fuel, then crank from there - if it starts you know its a blockage from the tank end of the system.... probably the in-tank strainer, otherwise blockage in the pipes. you could also swap the feed/return pipes around.

after 1000 miles approx the filters often clog when 1st running on veg as it cleans all the rubbish of the side of the tank and it gets stuck in the in-tank strainer and the pre-filter (which i believe you've already cleaned out).

get an assistant also to check the clear pipes to see if fuel is working its way around the clear pipes as you crank.

how much fuel is showing on the fuel guage? 1/4 tank???
good luck

Derek

That's a good tip on the glow plug relay. Now I have to find it! The car has between a half & a quarter of a tank.

Derek, do you know where the fuel tank strainer is located? there seems to be some discussion on whether the C250 has one.

Do you know how many O rings there are? Are they hard to get to?

Ta.

EDIT: Also, can you direct me to where the glow plug relay is to be found?
 
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glow plug relay is on the passenger side of the car.... just infront of the strut probably (assuming similar to my E300D)

the tank strainer; yeah i've seen the comments on the veg site - the merc EPC shows it on the parts diagram so i reckon there is one - i cant see why there wouldnt be....

search on here for "clear pipes" and you should find diagrams of the orings - its all the orings on the clear pipes around the fuel filter.
 
The car is now running. Thanks to everyone for your suggestions.

We didn't do a hell of a lot to it.

1) Took off the pre-fuel filter & fuel filter, which were both just about empty.
2) Unplugged Glow plug relay.
3) Tried to unplug stop solenoid & couldn't.
4) Opened fuse box & ECU box, had a look & closed 'em up.
4) Cranked car to see if any fuel came out of where filters had been. It didn't.
5) Filled pre-fuel filter with diesel and cranked until empty 4 times.
6) Filled fuel filter with diesel & screwed it down.


After this I turned the car car on & it started instantly, idled for about 10 minutes on the driveway & then drove faultlessly for 10 miles including gentle cruising & full kickdown acceleration.

I'm guessing the fuel filter was the culprit & the system was starved of fuel. We primed it, it fired.

Not 100% confident in this diagnosis so if anyone has an alternative theory I'd be glad to hear it.
 
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