I have done quite a bit of searching on the internet to land here in what seems like a knowledgeable group. Hopefully i didn't miss what i was supposed to be searching for.
We bought a 2008 Yukon Denali XL in January with about 110k miles on it. It ran great until about 2 months ago when we would start to have a very rough idle, only in gear and some weird shifting. My wife took it to 2 shops, the first said it was the idler pulleys and that he wanted about 400 to replace them. I opted to spend the hour to do that and the belts myself, with no change. The second shop concluded that it was an oil flow issue and wanted to conduct a $300 reverse flow test of the oil system, considering that there was no tick, or indication of poor flow, we didn't decide to go that route.
Since the issue changed between shifting between park and either reverse or drive, I figured that the problem was with the TCM, after a bit of searching I found reference to the Dorman site that indicated that the solenoid material wasn't designed for high heat, yada yada. So after replacing the unit the transmission shifts amazing, the rough idle is reduced and things seemed slightly better.
We opted to address normal wear items; plugs, wires, and o2 sensors. Since then there has been several issues with a p1133 and p1153 code for the front o2 sensors. Figuring that we got bad ones, I replaced them with AC delco ones and still have the same issue.
I am not sure where to go from here, occasionally there sounds to be an exhaust leak, which I am thinking that is coming from me pulling the exhaust pipe down to drop the tranny pan and such. but barring that, when putting the truck in gear, the rpm speed still changes at idle and drops to around 500 rpm. I am not sure what I should do from here... the exhaust leak is easy to chase, the change in RPM not so much
We bought a 2008 Yukon Denali XL in January with about 110k miles on it. It ran great until about 2 months ago when we would start to have a very rough idle, only in gear and some weird shifting. My wife took it to 2 shops, the first said it was the idler pulleys and that he wanted about 400 to replace them. I opted to spend the hour to do that and the belts myself, with no change. The second shop concluded that it was an oil flow issue and wanted to conduct a $300 reverse flow test of the oil system, considering that there was no tick, or indication of poor flow, we didn't decide to go that route.
Since the issue changed between shifting between park and either reverse or drive, I figured that the problem was with the TCM, after a bit of searching I found reference to the Dorman site that indicated that the solenoid material wasn't designed for high heat, yada yada. So after replacing the unit the transmission shifts amazing, the rough idle is reduced and things seemed slightly better.
We opted to address normal wear items; plugs, wires, and o2 sensors. Since then there has been several issues with a p1133 and p1153 code for the front o2 sensors. Figuring that we got bad ones, I replaced them with AC delco ones and still have the same issue.
I am not sure where to go from here, occasionally there sounds to be an exhaust leak, which I am thinking that is coming from me pulling the exhaust pipe down to drop the tranny pan and such. but barring that, when putting the truck in gear, the rpm speed still changes at idle and drops to around 500 rpm. I am not sure what I should do from here... the exhaust leak is easy to chase, the change in RPM not so much
