Problem Reports

My service engine soon light would come on and go off repeatedly. My truck began to idle really rough with low rpm while stopped at an intersection. I went to my local GMC Dealer and they diagnosed it as needing new cylinders and the extended 7 year 100,000 mile warranty covered everything.

I believe this is the problem with my 2006 canyon. I have brought the truck in at 33000 miles when check engine light came on, they replaced the emissions canister valve, computer read po 300 and po499. I brought truck to a shop when light came on again and was told to bring to a gmc dealer because test was done and he found cylinders 2 and 5 to have misfired the most. Gm service ran the computer again came up with po 300 and po 449 again. They wanted to replace the same part I replaced under warranty a few years back.Replaced the part and was right back the next morning with check engine light on. hooked to computer again and still reads po300 which is a misfire but they claim the leak down test is within the allowable range and have no idea what is causing the misfires. waiting to hear what they come up with next. I think it may be time for me to call GMC myself and start complaining.

No compression in cylinder 2 & 4...will probably have to replace engine...LAST GMC I will ever own. Had oil changed every 3K miles and always babied this truck....really let down...looking at a Nissan with a more reliable V-6.

i have been having a problem with misfire on all cylinders, just paid $300.00 to have fuel injection service done throttle body assy cleaned, code was p0300, still runs like crap. bought new in 2006

The engine light started coming on when my Canyon was about 3 years old. It would go out after a while and I was advised it was probably the gas cap. Unfortunately the cap broke after the warranty was up and I replaced the cap.The light continued to come on and a scan revealed it was for a misfire cyl 5 so I replaced the plugs and swapped the #5 coil with #3. I checked the compression and all were about 175 psi except #5 which was 140. The light again came on for cyl#5 so I'm guessing I have the valve seat problem I've heard about. The idle is becoming rough.