ml270 poor fuel consumption

[tony jr]

I have a 2003 ml270 with approx 155K on the clock. I usually find that I get around 28mpg in winter and around 32mpg in summer. For some reason I had a large decrease in mpg (down to 22.8mpg) last week and I'm not sure why!the 4 weeks before that had all been 28mpg. My thermostat is ok and the car drives very well apart from the poor fuel consumption. Any ideas?

 

[rjevon]

Can you post a pic of your thermostat at normal operating temp, as I think mine is too low.

I struggle to get anything over 26 ish.

All injectors replaced, over time, air flow meter and no faults showing. Also did the EGR shunt. Nothing has made a difference.

Richard

 

[rpe2]

The engine should run in the high 80's c

 

[tony jr]

engine temp around 83 degrees centigrade

 

[tony jr]

Can you post a pic of your thermostat at normal operating temp, as I think mine is too low.

I struggle to get anything over 26 ish.

All injectors replaced, over time, air flow meter and no faults showing. Also did the EGR shunt. Nothing has made a difference.

Richard

I keep a note of my mpg each time I fill up so I know what I would normally expect - I was surprised that it had suddenly dropped from to 22.8mpg - not a gradual drop off

 

[oigle]

I keep a note of my mpg each time I fill up so I know what I would normally expect - I was surprised that it had suddenly dropped from to 22.8mpg - not a gradual drop off

If it was only with one fill, it could easily have been the result of a short fill previously. I'd run a couple of tanks to make sure before worrying. Is it blowing plenty of black smoke under load? If so, you have an issue.

 

[rjevon]

I keep a note of my mpg each time I fill up so I know what I would normally expect - I was surprised that it had suddenly dropped from to 22.8mpg - not a gradual drop off

Did you actually resolve this Tony_jr ??

Richard

 

[tony jr]

I did not do anything but the fuel consumption is back up to around 28 mpg