W163 ML270 CDi won't start when hot.

[andywsr]

Hi,
My Ml 270 has developed a problem causing it to not start when hot or warm.
The engine turns over but will not fire, like it's not getting fuel.
Local garage has scanned the vehicle and found no faults which would cause the problem.

Has anyone had this problem before?

If so what was the problem and the cure?

Thanks in advance

 

[Hartzpartz]

Fuel system air leaks? Has the fuel filter been changed recently?

 

[andywsr]

Hi,
no fuel system filters changed recently.
Once engine has cooled down it starts and runs fine.
There are no visable leaks from anywhere.

 

[panason1c]

Might be the crankshaft position sensor faulty.... whilst cranking (when it won't start) , does the rev counter needle move?....if it doesn't, the cps needs replacing.

 

[andywsr]

Ok thanks I'll check it out

 

[BlackC55]

Or an injector is leaking off to much.

 

[Hartzpartz]

I'm with Panason1c on the CPS sensor theory. Had the same 'hot' fault on my ML55 and a new sensor cured the problem.

 

[andywsr]

Ok thanks for the info

 

[davidjpowell]

I'm with BlackC55. He knows his stuff and I've also seen this fault in the same way.

 

[Terry_]

It's very likely olly is right. Easiest way to tell is some high ignition in a can (ie easy start). If she fires and runs it'll be an injector
If not look else where

 

[oilslick]

hard to start

My clk 270cdi was getting harder to start when hot, it was ok when cold, had it diagnosed as injector fault, needed 2 reconditioned at £120.00 each.

 

[andywsr]

Just a quick update. I can confirm having replaced the Crank Position Sensor that was indeed the problem. All now working perfectly. Thanks for the help.

 

[Daisydog]

Crankshaft position sensor was problem with mine , cranked over but wouldn't start , changed sensor all sorted now !

 

[vee.84]

Hi guys i have a ml 400 cdi with exact same problem cranks when hot but no start ive changed crank and cam sensors but still same but the guy i got it from couple weeks ago did say he changed fuel filter could this be something to do with problem hartzpartz any idea guys apart from this car drives lovely with no issues

 

[Hartzpartz]

I would carefully check all fuel line connections to the fuel filter and the 'O' ring seals for deteriation or damage. If there is a screw top to the filter housing, make sure this is seated/sealed correctly (no leaks etc. ). Any air drawn into the system could create problems. Hope you get it sorted soon.

 

[panason1c]

.......or, in this case with the cps having already been changed, I would suspect a faulty injector..... and I would carry out a leak-off test

 

[vee.84]

Gona get this checked out at end of month hopefully just want to know what i should tell him to check out if air was being drawn in wouldnt it it not start from cold cause mine starts fine cold just when hot ?

 

[Hartzpartz]

I must admit, it does sound more like more of a CPS problem but as you have changed that already.....?
Suspicious that problem occurred after fuel filter change so definitely worth a close inspection of the filter and adjoining pipe work.

 

[AdrianCH]

Might be the crankshaft position sensor faulty.... whilst cranking (when it won't start) , does the rev counter needle move?....if it doesn't, the cps needs replacing.

Hope you don't mind my messaging. I have a 2005 ML 270 CDI that has the problem of not starting in hot weather. Happening a lot at the moment. Am struggling to find a good garage that can deal with an oldish ML. I noticed you are in Somerset. Do you have any recommendations? Hope you don't mind my asking. Cheers. Adrian

 

[AMGeed]

Hope you don't mind my messaging. I have a 2005 ML 270 CDI that has the problem of not starting in hot weather. Happening a lot at the moment. Am struggling to find a good garage that can deal with an oldish ML. I noticed you are in Somerset. Do you have any recommendations? Hope you don't mind my asking. Cheers. Adrian

Give Steve at Avantgarde Motors a call. A well recommended indy in your area.
Bristol Mercedes-Benz Specialist – Avantgarde Automotive, Clevedon