merky benz C250 td not starting in cold weather

[charliefarlie]

Have a wee problem with my merky benz C250 Turbo diesel 1998 on an s reg ,she starts fine no probs up till the frost arrived then was dificult to start would start after preheat light went out as normal but would stop more or less imeadiately would try again same thing on the third go it went fine went all day no probs the following day same again but slightly different started then stopped hasnt started since the out side temp was minus 6 its now thawing and temp has risen out side to 4 over nil so getting less cold still it wont start even with charge booster on battery turn ignition on wait till glow plug light out then turn the key a litle further over turns engine but not fireing up , am wondering if it might be the heater plugs as engine turns over fine just not fireing .
I was wondering if there is an electronic switch or sensor gone phutt as cant see all 5 heater plugs going all at once unless of course their was only a couple working before the cold weather started and yes loads of diesel in the car .
Any thoughts on the matter before i take it to bits , any replies would be much appreciated thanks charliefarlie

 

[jay1983]

My ml270 cdi was doin the same. It's in the garage at the moment.
It looks as it had air in the fuel lines. The seals on the pipes have been replaced and according to the mechanic, all is fine now.
I pick her up 2moro

 

[Dieselman]

It is likely to be air leaking into the fuel pipes, or possibly a leaking injector causing fuel drain-back.

 

[charliefarlie]

Aye but why now in the cold weather as before it got cold it was absolutely fine no starting problem at all , have discovered previous owner has put in a much smaller battery than its supposed to have getting the proper one tomorrow blinking costly too , have checked the fuel lines and are all clean and dry same with pump no leeks .

 

[Hawkmoon]

It does not always show any leaks as the fuel drains back from the engine to the tank or the diesel pressure is too low apparently the solution is either install a Non Return valve kit if it is draining back or if the diesel pressure is low you need the MB retro kit A2024700193 also check the seals on the preheater as they perish and allow air into the system. If it is simply a problem with the fuel draining back a simple fix is to try parking the car in a nose down position if it is nose up then it is more likely to drain back.