Rough Idle...any Thoughts?

[dblj1500]

I have a 07 GMT-900,4.8 with 37k on it. I had a issue about 2 months ago with my engine light coming on and a bad rough idle problem. Turned out to be the # 2 cylinder plug wire popped off and that was that. Well for the past month now when the truck warms up it idles kinda rough. Not as bad as before and now lights/codes but the rpms will jump like a 100 up or down. My truck when warm usally idles at about 500. Also the truck will shake a bit too with the idle. Anyone run into this kinda problem? I hate going to the dealer but if the problem persists, I will. Just wanted to get some thoughts on this, Thanks, Justin

[98 Z71 SLT]

Check your plug wires again

 

Never heard of them 'popping off"

 

You also have 5yr 100k powertrain warranty. Use it.

[dirtfan21]

Did the #2 plug look ok? I had this issue with a past truck and the ceramic on the plug was cracked. Swapped the plugs and no more issue. I would say pull that plug and take a real close look at it.

[dblj1500]

Yeah, I hear ya on the warranty. It might just come to that. The #2 plug did look normal because i did pull it to see if there was any issue with it. It's going to warm up here next week and I'm going to pull some plugs and check all the plug wires too.

[desrtrat]

try cleaning your TB real good, and your MAF while your at it. also a can of Sea Foam in the fuel tank can't harm ether..

 

good luck

[jro909]

vortecs have a rough idle naturally, but if we are talking like bounceing rpms and warning lights going off..haul ass to the dealer, make that warranty your bitch

[dblj1500]

I've done seafoam. I just did a oil change. I havent cleaned the TB in about 6k So maybe I'll try that and see what happens. If no change by mid week or so I guess I'm calling the dealer to get in. Thanks for the help, Justin