Mercedes Vito Diesel won't start now it's cold?

Question

Hi I have recently brought a Mercedes Vito Diesel 108cdi 2003. I have had problems with it starting now it's cold. I have put new glow plugs in and keep putting it on charge both on and off the vehicle and it's turning but not starting.

It'll start on tow and sometimes if I jump-start it off a blokes car down the road but it's getting embarrassing every morning.

Can anybody please tell me what else it could be?

Thank you.

Answer 1

You need a new battery with plenty of cold cranking power, if it starts off a jump start then that's usually the problem, diesel engines rely on good glowplugs and a decent battery for cold starting, other than that, start looking at cylinder compressions, fuel pressure, injectors etc.

Answer 2

are we sure glow plugs are working? odds are if not them then cold start system is at fault. no worth messing around. dealer can run a diagnostic check and pinpoint area of issue.

since it seems temperature related we will be looking at non ignition of fuel on initial injection . diesel needs heat to start ignition process. cranking in normal temps compresses air/fuel mix and generates enough heat to start combustion.

when cold air and engine conditions occur.. not enough heat can be generated by cranking hence glow plugs. and fuel injection timing and enrichment .

if glow plugs are heating ( not just light for circuit coming illuminating on dashboard) then fuel timing and injection ( cold start) is faulty.

hopefully a simple fault such as actuator/relay/sensor issue and not a new pump needed.

we can try as stand by measure only heating air into intake for few minutes before cranking eg hairdryer. paint stripper. others also use easy start - a fluid sprayed direct into intake to enable initial firing.

ensure cranking speed is ok ..too low ( poor battery?) will not enable sufficient crank /compression speed for fuel ignition to commence.

Answer 3

It could be anything from your confused and vague description. You need to get it properly diagnosed.



Take it to the dealership or other qualified mechanic immediately before you damage it further. I can't imagine why you haven't done so already -- save ignorance or incompetence.