Thanks, the dealership said that the problem described in the letter is the only open item covered under warranty for my truck.Man... I'm sorry. Here is the letter I got. I guess it was about the throttle position sensor. Take a look.
So for the valve issue alone, did they replace the valve guide that GCRuss was talking about? If they did and replacing the guides fixes the issue, then people with this problem can save a ton of money. Looks like most of the cost was labor, ~1300 dollars.Here is the invoice I received today from the shop. Keep in mind, they replaced the fan clutch, spark plugs, and did a minor service which is included in the overall price. Not as much as I thought it would be...
Probably a few years late, but the info in bold would be super helpful. Especially since the post quoted looks an awful lot like my issue.2008 Colorado, 3.7L, 10/2007 build date. Had Cylinder 5 misfire (P0305) while driving from WI to MD in summer 2012. Also had rough idle and issues on "warm" start (it would stall if started after resting for 60-90 minutes. Hot and cold starts were fine). Took it to the dealer in MD and they blamed it on my spark plugs. They also broke off one of the bolts that holds the coil down, so they had to replace the valve cover.
I went to Afghanistan for a year and got back to my truck about a month ago, and within a week it began having the same start/idle issues with the Cyl 5 misfire again. Moved the coils and plugs around, cleared the codes, and did a compression test:
Cyl1: 185 psi
Cyl2: 185 psi
Cyl3: 190 psi
Cyl4: 185 psi
Cyl5: 170 psi
Ran well for a few days, then PO305 came back along with the other issues. Truck had ~55,000 miles in 2012, and about ~63,000 now. It looks like my warranty expired in Dec 2012, 5 years after purchase. I go back for the leak down test on Wed. The dealer found the tech bulletin and gave me a copy (I can get the number later), but it doesn't list the VINs, only 2008-2012 Colorado.
Hey there Jon, its been a few weeks since your fix. Are all rough idle problems eliminated?From what I can gather, a standard valve job simply machines the seats and valves so that they seat properly. I can ask for the contact number for the machine shop they sent it to to ask exactly what they did. I like your plan.