Robert91RS

iTrader: (2)

I agree that it sounds like you still have a vacuum leak. I'm wondering if you have a cracked intake manifold. Also you might want to look for fel pros "revised and improve" intake manifold gaskets. They are metal rather than plastic and the seals are THICK black rubber. I only found out about them a couple of weeks ago but was very impressed with the design.

rmf2

Got a call from the dealership and they said they have identified the issue and repaired it. The plug in cyl 5 was defective, guess it had a small crack in it.

This is the first bad new spark plug I have experienced. I am going to drive it this evening and see if it is really all better. The mechanic did drive it with the tech 2 and the misfires were supposedly gone and it ran smooth.

Lets hope that this is all it is.

I will update again after I have it back.

Thank you to everyone who has helped and put up with my ramblings and rants.

Rich

rmf2

Seems that the cracked spark plug was the culprit, I drove about 70 miles tonight and didn't notice the missing and rough idle that I was experiencing.

Of course I could feel every bump in the road and the old worn tires that need a rotate and balance added to the feelings.

So far so good.

Thank you again for all the help and information

GMCtrk

iTrader: (27)

Glad you got it fixed, but I had saved you a few bucks there.

01Blackerado

iTrader: (4)

Haha you did call it!!!

GMCtrk

iTrader: (27)

it was pretty obvious.

rmf2

yes, you did. I had hand threaded the plugs in and just used the wrench for a final snugging.

Not sure where the damage came from or if had the crack in it before installation, and didn't come out until it went through a heat cycle.

I am guessing the increased issues after the truck was hot was due to expansion of the crack from the heat.