Rough idle '01 Denali XL

No SES lights or other codes have popped, but the idle is erratic and surges a lot especially when hot. About 88k miles on it, all stock. Runs fine once moving, doesn't die out at stops- just idle bouncing. Looking for places to start checking it out.

No SES lights or other codes have popped, but the idle is erratic and surges a lot especially when hot. About 88k miles on it, all stock. Runs fine once moving, doesn't die out at stops- just idle bouncing. Looking for places to start checking it out.

Try cleaning the throttle body and blade

Exactly. Also add some seriously strong injector cleaner and do a system "shock" trteatment.

Thanks, I'll give that a try and see. She's do for a tuneup soon too I imagine, so in addition to the usual stuff I'll take a look at the throttle body as well.

Been a great truck, best vehicle I've ever owned that's for sure and I love the extra power of the 6.0 vs. the 5.3L and 4.8s I've driven. Aside from the cold piston knock, I've had zero issues with it so far.