w202 starting problems

[jonc78]

Afternoon all, tried to start the old girl up this morning after a week of not being driven and she wouldn't start. It's almost starting but dies just before it catches. Got the rac coming out shortly to take a look but just wondering if anyone had any pointers to what this may be.
The car is a C200 estate 1999 model.

 

[television]

So hard to say what it could be, you could slacken a pipe going to the fuel distributor to see if fuel comes out while cranking.

 

[jonc78]

The rac managed to get it started. The guy just cranked for much longer than I did. I was worried about doing this in case I flattened the battery. The guy seemed to think the engine sounded flooded. He suggested I take it for a half hour drive which I did and this morning it started fine, so hopefully the problems resolved and it was just a case of it needing a good drive.

 

[EdGasket]

Maybe change the plugs and see if the old ones are oiled up. When I changed mine, I found one of the spark plug wells full of oil (spark plug under oil) and the next one half under. I don't yet know if that was because someone was careless or because oil is somehow leaking in there. Oil can leak down the threads and foul the plug making starting more difficult. Worn piston rings can also cause oily plugs.

 

[jonc78]

Maybe change the plugs and see if the old ones are oiled up. When I changed mine, I found one of the spark plug wells full of oil (spark plug under oil) and the next one half under. I don't yet know if that was because someone was careless or because oil is somehow leaking in there. Oil can leak down the threads and foul the plug making starting more difficult. Worn piston rings can also cause oily plugs.

The plugs were changed 4 maybe 5 years ago, so maybe they are due for another change. When I changed them that time one of the plug holes was full of oil (the one nearest the cabin) some I changed the spark plug seal on the cam cover and it's been fine since. I double checked the other day and it's still dry. I had intended to change all four of the seals but doing one was such a faff I just left the others. They still sitting on a shelf in the shed somewhere!

 

[EdGasket]

hmm maybe I should check my plug wells again. I never replaced any seals as it was the well closest to the oil filler and I just assumed someone had been careless when filling. Are the plug seals awkward to change then?

 

[ansta1]

The last time you ran it wasn't to move it was it. It's not uncommon for the ecu to gets its knickers in a twist if you start it from cold, run it for a very short period and then leave it overnight or longer.

If it does happen the trick is usually to crank it with the throttle fully open for a little while.

At least that's my experience.

 

[jonc78]

hmm maybe I should check my plug wells again. I never replaced any seals as it was the well closest to the oil filler and I just assumed someone had been careless when filling. Are the plug seals awkward to change then?

Yes, well worth checking again. Not too difficult to change, but I had trouble getting the new seal properly seated in the hole. Typical for me though I started the job without the correct tools! You need a round socket the same diameter as the seal so that it can be pushed/knocked in evenly. Otherwise you can get one side in and the other slips out. The metal on the cam cover is quite soft so you need to be careful doing it. The seals are only a few quid from Mercedes.

 

[jonc78]

The last time you ran it wasn't to move it was it. It's not uncommon for the ecu to gets its knickers in a twist if you start it from cold, run it for a very short period and then leave it overnight or longer.

If it does happen the trick is usually to crank it with the throttle fully open for a little while.

At least that's my experience.

Spot on! As it happens it was left for a week, then moved out of the drive and then left for another week. Didn't know doing that would cause problems, I'll be remembering this though. Been driving it all this week and no issues so far.

 

[Steed]

I agree with Ansta, if I start and stop my W202 C200 it then will not start again for hours.

I have learnt that once the car is started to leave it for at leat 10 minutes to warm up before turning it off.

 

[EdGasket]

I agree with Ansta, if I start and stop my W202 C200 it then will not start again for hours.

I have learnt that once the car is started to leave it for at leat 10 minutes to warm up before turning it off.

I have never had that problem on my C180 and I do just move it off the drive sometimes and leave it. I have, however, had that issue on my Hyundai which seems to go into some kind of 'flood' mode making it difficult to start the next time and then I do need to open the throttle fully to get it started.