I have a headache at the minute hopefully someone can point me in the right direction. Lets start the story off when i returned from france after the summer to find my partially laid up (family drove it from time time to keep 'er moving) e200 needed a litre of oil as advised by the display on the dash, which i did. my car test was out so i booked it in only to find it failed on emissions. it came back with a high reading. since i came back in september i have noticed the car always ran at a low temp while driving, i mean a REALLY cold temp and when i was stuck in traffic it heated back up to a mormal temp before dropping back down while on the move again. i never really acted on it which has probably left me where i am today!!! After returning from family over the xmas (80 mile motorway trip) i noticed the oil advisory came up saying "add 1 litre of engine oil at next stop". this warning came on about 15 miles from home so i continued home and straight away i pulled into get some oil. topped it up and continued home the last mile out from town to my house. Everything was fine until i tried to start it this morning.. it turns over fine but its just not firing, any ideas?

Main points.
1,Needed oil 3 months ago (1litre)
2,failed car test on emission two weeks after. (high reading. running rich)
3, Car running temp up and down (thought it might have been a stuck thermostat as advised by a friend)
4, needed oil last night
5, Wouldnt start this morning

 

2 and 3 are probably connected. Engine is running rich until it reach working temperature. Your friend is right. It is stack thermostat. But this and burning some oil won't cause engine not to start.

 

So a buddy(no means a mechanic) was over with me and i was telling him about the problem, he asked for the keys to have a listen and of course it started.. thought great maybe just a little mishap. drove it for a day or two and then the following morning it wouldnt go. as it was the holidays everybody was off so i couldnt do anything, another guy said try disconnecting the batt which would reset the ecu, so i did. Once again it started, drove it around, switched off, switched it back on.. so its gone again. will get it to a shop hopefully tomorrow but i just wanted advice regarding the actual problem. I dont want to get landed with hefty bill...

While i got it going i always heard the pump priming and when it failed to start the pump failed to prime. it seems a no brainer that the pump is dead but im slightly puzzled as to why it worked after the ecu was reset. make me think that it mightn't be as straight forward.

 

plus while it was driving it never gave any signs of shuddering or hesitation.

 

Get a scanner and scan for codes.
Failed emission should give you good pointers, but you did not act on it.
Same with driving with open thermostat.
You are not giving mileage between oil additions, so hard to tell if that was normal, or not.