I have an '07 H2 SUT that just hit 110,000 miles. Two years ago, u had the transmission rebuilt (warranty). For the past few months, I have noticed it feeling sluggish. First thing in the morning (driving around town) and when I drive the highway through the mountains to the beach, it feels like I'm towing a car. If I floor it, the transmission kicks down but it still feels like there's no power. I took it back to Chevy a week ago (who rebuilt the trans) and they said they couldn't recreate what I was trying to explain. I just dropped it off to another shop yesterday and they said the same thing. Something is obviously wrong but I have no idea what it is and there is not check engine light (no codes). I have read that it could be a list if things but I can't really afford to shotgun this.. My truck is all factory (no mods) and idles smoothly.. I feel like I'm rambling but trying give all the info..
Has anyone ever experienced this? Thanks..

 

110k, maybe more engine related than tranny. Have you replaced spark plugs, wires, possibly coils, etc? Maybe just a good tune up to bring it back a little would do the trick.

 

No, I haven't yet. I was thinking I would jump on here first. I didn't think it would be plugs/wires since it still idles smoothly.

 

LoJacs right, always start with the basics a good tune-up. Plugs, wires, air & fuel filter + clean out the t-body. I like to take it one step further and clean the injectors, (no not dumping snake oil in the tank) I own one of the 3M injection cleaning kits. With this the fuel pumps disabled and your truck/car runs off the 3M injection cleaner. It hooks up to the schrader valve on the fuel rails, this stuff is amazing and for cars/trucks with few miles the results are amazing! It cleans the injectors, intake ports, values plus the top of the pistons.

 

good lord, how the hell did you get your hands on one of those??

 

I would look into your catalytic converter. Sounds to me like it might be plugged up.

 

With 110,000 miles, when I chamge the plugs/wires do I also replace the coil packs?

 

I would think if they are working, no codes then the coils should be fine. Plugs and wires though I would definitely change at the 100k mark.

 

There 2 on our trucks. That's a lot of change to just throw at it with no evidence! Unless your looking for a reason to install hi flows

 

Might as well do LT's at the same time!!