2004 GMC Envoy • 6 cylinder 2WD Automatic • 117,000 miles
2004 GMC envoy SLT 6 cyl 2WD. Took in to change plugs (iridiums)and fuel filter. Brought home and SES came on. Returned vehicle, and the same thing happened again. Took to another shop and they indicated a misfire cyl6, code P306. Checked new plugs and no 6 plug was hard to remove and they noted cross threading in that plug. Did tap and once again, a misfire in cyl 6 with same code. Rechecked all plugs and coil packs switching those around to different cylinders with same result a misfire in cyl 6 with same code. Fuel economy has decreased by 25%. Engine starts immediately but idles roughly with trans in drive with brake depressed. When driving do not notice any miss and no loss of power. Engine does not backfire, or stall and no lurching or hesitation. Put can of seafoam in gas tank and no change. Did compression test and all cyls checked out okay. Any help is appreciated
January 23, 2011.
January 23, 2011.
Check out the related content while we wait for the question to be answered by a professional mechanic.
We have a 2000 Elantra GLS (auto) and have owned it since it had fewer than 10,000 miles on it. It now has about 130,000 miles on it. Here is a brief history: A few years after purchase...
1 answer • 2000 Hyundai Elantra • 13,000 miles
1992 Pontiac Sunbird SE 3.1 mileage 135,000. 1992 Sunbird, with 3.1 replaced from a '92 Cavalier in 1999. Car starts fine, drives fine for a few minutes in the morning, however after a ...
1 answer • 1992 Pontiac Sunbird • 135,000 miles
1990 Toyota Camry mileage: 150,000. 1. The oil warning light is on. 2. There are four quarts of oil in the car. 3. The oil filter is dry. 4. The engine sounds rough. 5. There is noise ...
1 answer • 1990 Toyota Camry • 150,000 miles
1970 Volkswagen van 1600cc mileage: 600. Hi and thanks in advance for your site. We have been enduring a nightmare with NEW engines in our very OLD Volkswagen. It began in May of "99" ...
1 answer • 1970 Volkswagen Van • 6,000 miles