Hi all am new to here and need help on this
I own a Mercedes E Class 300 td estate and I have a prob with it.
When I try to start the car the engine turns and it wants to fire up but instead it just flattens the battery. (the battery is new and been tested no probs) but some days the engine fires up with no probs but some days it will not fire up at all only turns the engine. (I have never run the car on empty always have fuel in it ) I have to re charge the battery to start the car and when the car is running for 5 mins I can go back to it in 3 hours time and starts no probs, but if I leave it over night then it will not start, and now it is getting to be a pain in the x%$@ as. I have many ppl say its my jets, to much air getting in to the sys, its my battery?? oooook, heat plug’s, fuel pump, the list goes on ahhhhhh Has anyone on here had this prob at all as I do not know were to start and my budget is low. Or any ideas were to start first as am not a mechanical Einstein on this type of car this is my first merc td
Many Thanks for any info

 

Glow plugs and sometimes no start. Sounds like a glow plug module. Had 2 W126, 1-W123, 1-W124, same on all. Got used to rebuilding the modules. No problem since.

 

sounds like the same prob I've just got. Check the clear fuel lines & pre-filter just before the main fuel filter. if they have got air in, there is a leak. initially suggest change both filters and O rings, then tubing, then trace back to tank intake. If its not air in the fuel its probably the glow plugs.