I have been experiencing detonation with my 05, (163,000 miles) lately. Has anyone experienced this? I use 87 octane fuel but have tried mid grade with no success. Any help is appreciated. Mileage still around 46 to 50 mpg. Matt
1. Try premium gas as an experiment, to see if there is any change. 2. If no change, maybe the knock sensor is not operating so engine ignition timing is advanced more than conditions warrant, resulting in engine pinging. In that case you might want to seek help from your local Toyota dealer or independent hybrid servicer.
Thanks, I will try the premium. How tough is the fix on the knock sensor? I use a shop that knows Toyota's, but not real experienced on the Prius. Matt
I believe that the intake manifold needs to be removed for access to the sensor, so this is not a trivial process. An experienced Toyota mechanic can do the work.
At that mileage I would pull the spark plugs and see how much carbon is in the cylinders. See how fouled they are with carbon. Post those pictures here. If really bad may respond well to top end decarbonizer treatment.
While you've got the plugs out may as well to a quick compression test to make sure you don't have a dead cylinder.
