1995 W124 E300 Diesel won't start

[TonyVianoAmbiente]

I have a strange problem with my E300 Diesel. After two and a half years of near total reliability, it won't start. I'm selling the car so I am keen to get this fault fixed before I advertise it in Auto Trader and on eBay.

SYMPTOMS

Engine turns freely but doesn't fire at all. Some unburnt fuel from exhaust suggests that fuel is getting through. The glow plug relay, recently replaced, is live with 12V at the glow plug terminals.

I called out the rescue service and they started the car easily with Easy Start. It ran well - I took it in to a specialist to be serviced - and it started fine later that day. Now it won't start again.

Any clues or suggestions will be warmly appreciated.

(Except selling it with a can of Easy Start!)

 

[bolide]

Air leak into the fuel system. Standard OM606 fault. There are hundreds of threads about this problem

Nick Froome

 

[TonyVianoAmbiente]

Thanks Nick.

If it is an air leak, why does it run perfectly once it has started?

 

[Number_Cruncher]

>>Engine turns freely but doesn't fire at all. Some unburnt fuel from exhaust suggests that fuel is getting through.

The only things diesels need to run is good compression and fuel being injected at the right time.

As a) you say there are signs of fuel getting through, and b) the car runs OK after a snifter, I would check the compressions.

Were you ever tempted to run the car on anything other than pump fuel?

 

[spock500]

Once the engine is running it will have enough rpm to give sufficient suction on the pump probably enough to over come the air ingress.

Have the clear pipes ever been changed?

If not an easy fix is to remove each pipe, prise the O ring off and wrap three turns of PTFE around, replace ring then another three turns - should be a nice snug fit requiring a twisting action to re-fit - try and twist the same way the tape is wound

Heres a pic of mine off a OM605 (same engine less one pot)

 

[bolide]

Because...

When there is air in the fuel system the injectors don't crack open. The pump pumps but all it does is to compress the upstream air bubble and the injector doesn't open

Once the engine has caught & is running the air bleeds through & it runs. A little bit of heat in the head works wonders

If you turn over a 606 with an air leak long enough it will run eventually - assuming the glow plugs are working. It can take 10 minutes and it's tough on the battery & starter

Nick Froome

 

[Number_Cruncher]

How does the unburnt fuel coming out of the exhaust, as mentioned by Tony in the top post, tally with the air in the fuel line hypothesis?

 

[spock500]

What is visible in the exhaust, is it neat diesel dripping from the tail pipe or just white smoke?

 

[spock500]

Any update ?