Rough idling 07 Yukon Denali...

[dogger37]

I have a rough idle in my denali that seems to keep getting worse. I've had it to the dealer 2 times now. The first they suckered me in to getting a fuel system cleaning that I thought was what they consider a "top end cleaning". They basically just dumped fuel cleaner in the tank and sprayed the thottle body with cleaner. I thought they were going to pull each injector and line and clean them. Second time back they say they have no idea what it is and want to now pull the injectors and lines to inspect and clean them. I said that I am not paying and they agreed to cover the expense. Im at 82,000 with a GMPP extended warranty. Has anyone else noticed a rough idle? If so have you found the cause?


Thanks in advance,
Donny

 

[Bigmike12]

I have the same issue with my 07 Denali at 54k miles. The problem is it isnt throwing any codes so no dealership can tell me what it is. First tried to do the intake throttle body cleaning but it didnt help. It is a rough idle like it almost sometimes wants to die right? Im going this morning to look at an 07 Cadillac EXT for trade in though.

 

[Modded]

Since its not the throttel body and fuel sending system, it may be you IAC valve related. After all the IAC does control you idle......

 

[TIM Z]

Could be a bad intake gasket.

 

[dogger37]

Dealer contacted me today and said that GM returned his call and stated that this rough idle issue/power loss has been reported by numerous customers/dealers. At this time they are not sure what is causing the issue and would be further investigating the problem?! So I guess I am just supposed to wait until GM has time to diagnose the issue and in the meantime cruise around in my Denali that has an idle like a cammed up big block and runs like a toyota echo?

At what point will I reach lemon status??

 

[sgalvin07]

I suppose I will chime in and say I have an 07' yukon with 80k miles on it.. It also has a shake at idle.. I first thought motor mounts, but after taking it to my mechanic he returned saying he thought it was the throttle body. He cleaned it out pretty well, and when I first picked it up it was idling nice and smooth.. fast forward a week or two and the shake is back....

Anxious to hear results that GM returns... keep us all posted please

 

[Mr. B]

I've got a rough idle too, at 41,000 miles. I haven't done anything with it yet. I bought it with 30,000 miles and it's basically been the same the whole time. I think it is very common on the 6.2s. I just figured that is how this motor idles.

 

[tamimi]

Hi,
Have you guys checked your Spark Plugs and wires ?

Yes I'm a newbie .. but at least I'm trying to help

 

[Rollin Thunder]

Dealer contacted me today and said that GM returned his call and stated that this rough idle issue/power loss has been reported by numerous customers/dealers. At this time they are not sure what is causing the issue and would be further investigating the problem?! So I guess I am just supposed to wait until GM has time to diagnose the issue and in the meantime cruise around in my Denali that has an idle like a cammed up big block and runs like a toyota echo?

At what point will I reach lemon status??

but cammed bigblocks are cool. lol

 

[Tonygxp]

the ls2 in my TBSS shakes at idle and has done it since new. The first time i heard a 6.2 idle and move at low speed in a cadilac showroom in 07' I couldn't believe how noticable the LSA in the cam was. I was surprised it seemed to idle like it was going to stall. I remember thinking I don't have it that bad if this is what the full size guys are going through. I also don't believe in the 100k tuneup schedule nonsense either. give it a full tune up i bet it'll run like new. Which is another possibility due to it not throwing any codes. Could it be a gasket? yeah, but if this is their answer "we don't know" then i doubt it. those things are easy to spot because more than a few would have a particular gasket replaced and the grapevine would've gotten it back to your dealer.

PS cleaning the MAF makes it run a little smoother, fattens it up, they begin to run lean when the maf gets a film on it every few months (or sooner). My TBSS been on a dyno enough to see a .5-1.0 change in air fuel ratio when we clean the MAF after a baseline, it's always in need of a cleaning. good luck. until it stalls chalk it up to having a 403hp 6.2 small block in need of a tuneup. cant have that kind of power without giving up something lol unitl you get used to having a "cammed" small block it can be annoying and then once you're finally used to a cammed small block it's got maintenance issues.