[Skithis]

I have had my Colorado now for a few months and have noticed a few issues. First off, About once every week or so when I cold start the truck and back out of a parking spot while turning, it seems like the rear diff is locked up. It will lurch pretty good on dry pavement. I attempted to change the oil a few months ago but the plug is seized into the diff and I broke an extension off in it. Waiting for the weather to get better. Any thoughts?

Secondly, When driving down the highway at 75 the truck will randomly pop out of overdrive and kick my cruise control off. Sometimes It seems as though the truck doesn't know which gear to be in. Tranny fluid is full and smells fine.

Lastly, When started cold the truck has a rhythmic engine miss. Not a cylinder miss though. As if somebody was tapping the throttle every second. IAC?

Any input would be great! Oh, btw its an 04 z71 w/ 3.5l 5 banger

 

[limequat]

Any codes? Scan it even if don't have a MIL as not all codes set the MIL. I think you may have a failing brake switch causing the intermittent cruise problem.

What's the difference between a cylinder miss and an engine miss?

 

[Skithis]

I suppose I explained that badly. It is not a misfire, its more of a irregular idle. But it is in perfect rhythm. Its hard to explain a sound in words!

I'm also having issues with my abs coming on all the time even when im not touching the pedal. Sometimes when im just cruising I hear the ABS servo come on and start humming randomly. I just assumed this was a bad wheel speed censor now that I know about the common issue with these trucks. Could this also be a sign of a brake switch? What does this brake switch do? Just brake lights and cruise cutoff?

 

[Skithis]

Oh and I did try to pull the codes and got nothing.