Rough Idle
I have a new issue will my 03 Chevy 6.0. When the truck is cold it idles rough. Doesn't actually feel like a misfiring cylinder. In gear at a stop light the idle will drop below 500 rpm and the engine...
Forum Discussion
Thunderbolt wrote:
I confirmed this morning that my intake gasket is leaking. I started at -4 degrees and once it was off fast idle it started stumbling. I started spraying carb cleaner along the intake and when I got to the driver side rear the engine smoothed out.
Good catch. Sorry I was wrong on the IAC. I had thought the 6.0L had the same separate IAC as other GM's.
While you have the intake off you might look at the knock sensors. My 6.0L only had 2 problems in 10 years of ownership: exhaust manifold bolts and corroded knock sensors. Both of those are extremely common on the LS motors.
Since you'll have the intake removed it's a great time to inspect the knock sensors and replace if they are corroded. The TSB for the sensors shows to make a dam of RTV around the sensor cover with an opening to the rear. Here is a PDF of TSB #02-06-04-023A.
I have 2 additional suggestions:
1) Remove the foam seals at the front and rear of the intake. In my opinion these help to trap moisture and don't really do much other than a slight sound deadening.
2) Replace the knock sensor harness. On my truck I replaced the rear sensor and not long after kept getting intermittent CEL's for the sensor. It turned out the wiring harness also had issues so once again I removed the intake and replaced the harness. That finally solved the problem for good.
KJ
