With the engine apart, we have way too much carbon build up for the 30,000 miles since it was last open.

We did have an Oxygen Sensor Error from the CEL so, no doubt that could be the cause.

Any other thoughts on why a heavy carbon buildup after 30,000 miles?
-Always used 93+ Octane gas
-Daily Driver, but interstate so should have been adequate blow out during normal drives.
-Yes, gas mileage was so/so -- maybe 18mpg when most of the drive is on Interstate.

Thanks for any ideas.

 

How much is too much carbon? I always go with this saying "redline a day keeps the carbon away" although I've always redlined more then that. Add water injection.

 

Maybe put up some pics. Rotors get coated in carbon VERY fast.

Also, if the O2 sensor is bad, the stock ECU runs the engine rich, that will definitely help carbon it up quick.

Dale

 

what about "leaking injectors" would that also be a candidate for carbon buildup?