Terrible MPG on Kompressor

Trueblue1872

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Hello again Guys/girls.

I have had my c180 2004 kompressor now for over 1 year and have always noticed it had been quite a thirsty car on fuel but lately its getting considerably worse. I am getting aroung 20mpg around my city and not much better when i was on the motor way yesterday.

I am currently racking my brain to think wgat can be causing this. Its either my MAF sensor that is causing the erratic gear changes which are not very smooth at times. I also was wondering if the Timing Chain has anything to do with this or maybe a combination of these plus other things adding to this Low MPG if anyone has any ideas this woukd be great. Many thanks
 

malcolm210

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It might be the thermostat, does the car warm-up properly if not this will affect the mpg as you describe. My 350cdi is going in for a new thermostat which is currently stuck open the temperature gauge never getting above 60 deg, consequently the consumption is down at least 7 mpg due to the ecu overfuelling. Another tell tale sign is the tickover will remain high for a long period
 
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Oldspanners

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C CLASS 2004 C180
Hello again Guys/girls.

I have had my c180 2004 kompressor now for over 1 year and have always noticed it had been quite a thirsty car on fuel but lately its getting considerably worse. I am getting aroung 20mpg around my city and not much better when i was on the motor way yesterday.

I am currently racking my brain to think wgat can be causing this. Its either my MAF sensor that is causing the erratic gear changes which are not very smooth at times. I also was wondering if the Timing Chain has anything to do with this or maybe a combination of these plus other things adding to this Low MPG if anyone has any ideas this woukd be great. Many thanks
I agree with Malcolm, my car the same as yours recently showed signs of lower mpg during the cold weather and on checking the water temperature on the dash menu it was barely above 40C. I changed the thermostat, easy job on this engine and things seem back to normal but I still have only done short journeys.
Oh don't buy a QH thermostat you'll spend more time adjusting it to make it fit.
 
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Trueblue1872

Trueblue1872

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Thanks for the reply guys. My temp has been very stable and isnt below 80 when at operating temp. I had a obd code prwvious and it was showing that the MAF sensor had issues and also that the systen was running rich and lean.
 

Wighty

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Would basic service stuff like air filter and spark plugs contribute to poor mpg in this case ?
 
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Trueblue1872

Trueblue1872

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Yep air filter has been changed alont woth the cabin filter only thing left to do is a full oil change.
 

LostKiwi

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Have you tried resetting the adaptations in the ECU? (requires a decent code reader)
 

Oldspanners

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The codes had pointed in the direction of the MAF sensor and also possibly a lambda sensor.
Have a look for oil in the after cat O2 sensor connector as a sign of oil wicking from the cam magnets if they haven't been changed and blockers installed. This affected the mpg on my car as well.
 
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Trueblue1872

Trueblue1872

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Im in the process of trying to get new cam magnets as they are leaking a little oil.
 

Wighty

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Are you tyre pressures ok , and also not lugging a load of unnecessary weight in the boot ?
 

Oldspanners

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Im in the process of trying to get new cam magnets as they are leaking a little oil.
It's not the external leak that's the problem it may be oil wicking up the wiring harness and effecting the sensors and ECU connectors. Blockers are required to stop this and I found it necessary to clean the connectors with contact cleaner and compressed air a few times to clear it.
 
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Trueblue1872

Trueblue1872

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Im quite goid at keeping in top of things such as the tyre pressures and checj them weekly and they all seem good.
 
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Trueblue1872

Trueblue1872

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It's not the external leak that's the problem it may be oil wicking up the wiring harness and effecting the sensors and ECU connectors. Blockers are required to stop this and I found it necessary to clean the connectors with contact cleaner and compressed air a few times to clear it.
I read online and seen a video saying something about a retro fit ??
 
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Trueblue1872

Trueblue1872

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