C250 TD not starting

[ali.shaikh22]

Good Morning

I have a Mercedes C250TD and I cant for the life in me figure out why the car will not start.

140K, recently serviced, fuel filter, air filter, oil & filter approx 1000 miles ago

Car was running beautifully smooth although on the motorway at times it would feel as though it would skip a beat, you would feel for a split second.

I put in some injector cleaner and the car did feel stronger.

Recently we've had some really cold weather, tried to start the yesterday, car tries to turn over but no spark.

Ive got enough diesel, the battery is strong.

I have no idea where to start investigating as im used to the petrol variants.

I have checked the clear pipes coming to the fuel filter and there are no bubbles in there. I have also left the car on ignition and the plug indicator has gone off

However to the side of the manifold just under the engine cover is some leaked oil/fuel? I have not removed the manifold? but this has always been there. See attached pics

Please can anyone give me any pointers as to where to check?

 

[guydewdney]

Classic problem of the thermostat leaking. Take off manifold and replace pipes or at least the o rings. Might also be the injector 'elements' leaking, thats the bit where the small hard pipes come out of the inj pump. Also do the stop solenoid o ring, do a search, plenty of info how, whilst you are at it.

 

[ali.shaikh22]

Hi

Thank you for replying, so the thermostat is leaking water/coolant? i'm about to take off the engine cover and check the holes for any fluid. Ive read this can be fuel thats leaked? im guessing my glow plugs are fine as the light comes on and then within about 30 secs goes off again.

If I do take off the intake manifold will i need any new gaskets etc to put back on or should it just bold back on?

 

[guydewdney]

No, the thermostat housing is a known air leak point. The intake manifold has a steel type gasket that you can get away with not replacing. Im sure that merc will tell you to replace it! If you have a battery drill, and an adaptor for the torx bit, crack all the torx screws then wizz them out, or get RSI from the repetitive action! The rubber tube that joins to the cross over tube is known to split, check it.

 

[ali.shaikh22]

Hi

Ive taken the cover off and checked the holes under the cover, they seem completely dry.

Do the torx screws need to be replaced onced cracked open?

Ive read about the stop solenoid but not able to locate it.

Apologies for sounding thick but once the manifold is off do i just want to clean the area and replace the o'rings, by replacing the pipes i assume the gold fuel pipes?

ive attached a video on youtube with the engine sound

Mercedes C250 TD not starting - YouTube

 

[neilrr]

Might be this - http://www.mbclub.co.uk/forums/engine/46543-howto-diesel-delivery-valve-leaks.html

 

[ali.shaikh22]

Hi

Im going to look at the stop solenoid first, after reading about i think its next to the fuel filter at the front of the car, the 10 mm to the left of the fuel filter holds the stop solenoid in place? so will there be an o'ring underneath? just trying get an idea of what to expect. any picstures would be helpful

 

[ali.shaikh22]

is the stop solenoid the same thing as a pre fuel filter?

 

[guydewdney]

No. The stop solenoid is under the inj pump, its black. Theres lots of info on how to replace it. No you dont need to replace the bolts. Dont over tighten when replacing, its asy to strip them.

 

[ali.shaikh22]

cool ive found a pic of the stop solenoid, how do i check if this is faulty? im guessing the manifold still needs to come off for this. Should i check the seal on the pre-fuel filter first?

On the left hand side of the engine when looking at it from the front, ( so the steering wheel is on the left when looking) in the top corner there is something which looks like a paper filter with a plastic see through housing. I think i saw something like this on my vw golf. is this part of the fuel system? a pipe leads to it but nothing goes from it

 

[guydewdney]

filter thing near the brake master cylinder? something to do with the vacuum system. ignore it.

no - you can do the stop solenoid without removing the manifold. remove the washer bottle makes it really easy. you need a 27# torx iirc and a short extension. ideally a 1/4 drive ratchet or stubby. wear gloves as its filthy. make sure you get the RIGHT torx bit and get it in properly or its a bitch as you have to drill out the bolts when they round off.

theres a howto on here isnt there?

 

[ali.shaikh22]

excellent, i shall take a look at the stop solenoid, but what exactly am i looking for? if the rubbers are perished?

 

[neilrr]

The stop solenoid may or may not be faulty but fixing it doesn't address the very obvious fuel leak you have, which is much more likely to be the cause of any starting problems.

I'd resolve that first.

 

[guydewdney]

<sigh> - theres LOTS of info on here about this issue. Theres a search button at the top.

the O ring inside will be deformed allowing air past. it needs to be replaced. its a bit of a funny size and either buy the kit off ebay or the genuine one from merc - about 50p

 

[hondo]

If you continue to turn car over probs need a jump start and if you can get nose of car pointing down hill(this will make it much easier) it will eventually start even with this leak and drawing air

Once you get it started and it's been running for 5 minutes shut it off remove inlet manifold which in my experience has no gasket just o-rings make sure no debris or anything about around inlet ports and start it again with manifold off this way you will hav a much better view of where it's leaking but be very careful not to let anything get sucked in to ports or ur engine will be gassed ,and just let it idle DNt rev it with manifold of

 

[ali.shaikh22]

Hello all

Managed to change the o'rings on the pipes, just changed a few of them, the existing ones didn't look too bad but then the pipes were hard work with the new rubber pipes to get back on. Also changed the O'ring on the stop solenoid. CHanged the O'rings on the manifold too.

Filled the pre-fuel filter with diesel and tried to crank over but no joy, tried easy start in the manifold as I tried to turn over and after quite a few go's it started!!!

Its been running fine and got it filled up to half tank.

Just wanna say thanks to everyone on here...

Have a fantastic Christmas and a great new year

 

[ali.shaikh22]

Hello changed most of the O'rings including the stop solenoid and the air manifold filled up the pre-fuel filter with diesel and tried to turn over but no joy, eventually sprayed easy start into the intake manifold and after quite a lot of turns the car started and is currently running

Thank you all