Poor starting when cold Ml 270 cdi

[mercaddi]

had my 2003 W163 ML for about a month and has recently become really temperamental when starting from cold sometimes it will fire and die immediately then needs about 30 seconds of constant churning or strangely it will start immediately if i park it facing forward down a slope. I am new to diesels so not sure what to look for!! Could anybody suggest where I should start looking? thanks.

 

[Benza750]

Sounds like you have an issue with air getting back In to the fuel lines.
Or a leaking injector, where the fuel is passing straight through the injector back to the tank.
Start with replacing the O rings on the ends of the plastic fuel lines.
Some people will say on here to replace all the fuel pipes but if it is done carefully you only need the O rings
Only use Mercedes o rings aswell, most dealers will stick them.
If heck ops that hold the fuel lines in place are damaged then you need to replace those fuel lines aswell

 

[mercaddi]

I will take a look at them and see if it helps thanks for such a quick response much appreciated, should i swap the fuel filter while I am at it? Too bloody cold to work on it today though!!

 

[sspeed]

I am 90% certain its an air issue..
I have just replaced the O rings in my C270 cdi...
Look at the front of the engine where the 2 fuel pipes join the pump.. Is it damp / wet?
See photos..

If it is then therew is your problem..
There are 4 O rings but its highly likely its the 2 at the front (mentioned) that are the problem as they go through thousands of Hot/Cold cycles..They get MUCH hotter than the other 2 O rings..

The part number for the O rings is:

MBA601 997 06 45
Remember you need to order 4 !!!

 

[mercaddi]

Thanks a lot you guys are great - glad I joined I suspect that I will be a regular visitor!!

 

[paulmhanna]

I am 90% certain its an air issue..
I have just replaced the O rings in my C270 cdi...
Look at the front of the engine where the 2 fuel pipes join the pump.. Is it damp / wet?
See photos..

If it is then therew is your problem..
There are 4 O rings but its highly likely its the 2 at the front (mentioned) that are the problem as they go through thousands of Hot/Cold cycles..They get MUCH hotter than the other 2 O rings..

The part number for the O rings is:

MBA601 997 06 45
Remember you need to order 4 !!!

Hi, I have the same problem which started last month with the very cold temeratures.

I've purchased the seals, is a simple job to do without breaking anything? My ML is a 2001 with 107k.

Regards

PMH

 

[malphadour]

CLK 270 CDi here - exactly the same engine, exactly the same problem - I went for the new pipes option as I could not be ****d *****ing around with O rings and also one of my pipes looked a bit fragile as well; same result as the other guys, starts perfectly now.

This is a notorious problem on the sprinter engine - another bit of unreliablity built in buy mercedes penny pinchers unfortunately.