2007 H3. I5
Why is the fuel consuption worse? Trying to fix this problem. Had a code for the coolant thernostat. Had the system flushed and thermostat replaced. No more codes at all. Temperature gauge reads between half and three quarters. Before it was replaced the gauge read below half.I understand that the reading now is normal.
My fuel consumtion went from 17 Ltrs per 100 km to 21- 22 ltrs per 100km.
Engine runs smooth, good acceleration. No codes. It has been a few months since the repair has been done. Therfore i do not think it can be the system.
No luck looking it up on the internet, found nothing. Any help would be greatly appreciated.

Thanks

 

Have you changed driving habits? Tires? Weather changed? Seasonal gas change?

Grasping at straws here lol.

 

Have not changed habits. This seemed to happen right after the termostat and cooling system flush

 

It is strange. Cannot find a reason for it.

 

Yes, that is strange. Is there an air pocket perhaps? Maybe clearing the ECU? This forces the system to relearn. Filter really dirty? Strange.

 

Clearing the ECU. Buy removing the battery connections? It is worth a try.

 

Your temps are lower than before thermostat went bad. Is the new thermostat a lower temp range? The pcm is programmed for a temp range and if thermostat is making it run cooler the pcm will make it run richer to try to make it run hotter.

I moved my thermostat to the top of the motor. I also run a lower temp stat. I have lived with the lower mpg knowing it will be this way until I can get pcm of nc to reprogram.

 

I had the work done at a garage. They tell me they only purchase and install OEM parts. The temperature gauge is running higher than before the code being displayed. I have now reset the PCM. Hopefully after some driving and the pcm reseting itself will remedy the problem.

Thanks to everyone for the help. Will let you know the results.

 

Disconnecting the battery does not reset the PCM, it stores the last 300 ignition cycles whether power is on or off.

If you were comparing last summer/late falls' weather to driving in Jan-now, outside temps and fuel composition (winter blend vs summer) can create that difference. See if it goes back up when the refineries switch back to summer blend.

 

Hello,
I have a Hummer H3, 2006, 3.5, I do not know how to check the fuel consumption on my internal computer.
I am new and I have a car from 2 weeks, help me please. Thank you, greeting, Henry