Maintenance question GMC Acadia idle stumble


Ready to race!
Hello All,

This forum and the other golf ones have been invaluable to me for my VW service needs over the last 13 years. Joined the Acadia forum for my new kid hauler and the people all just point to the dealer and fear self diagnosis like the plague and are down right rude about it.

The car:
2017 GMC Acadia 3.6L Denali 21k miles

Issue: car is perfect except it stumbles at idle in park/drive/neutral ever so slightly. Like someone is nudging the car. Runs totally fine other than idle. No codes or errors. Dealer won’t help as they can’t feel it (like all dealers). Unsure if related but it smells super rich when warming up in the garage in the mornings (door open obviously).

Tries so far:
Vacuum lines seem fine
New air filter
Snugged throttle body bolts
Cleaned throttle plate
Reset throttle body
Fresh gas
Injector cleaner run through gas tank

Further thoughts:
Spark plugs to be changed
Idle air control valve?
Clean MAF maybe?

I’m at a loss if none of that works. Any thoughts from the VW self maintenance masters?

Hoping spark plugs and maybe some spray cleaner on the MAF and IAC valve will smooth it out.


Go Kart Champion
start with plugs. I would think its probably either that or the MAF. Maybe consider ignition coil?


Ready to race!
I always think of VW and failed coil packs but have never heard this with other brands. Maybe I’ll start with plugs and just go from there.