Bought my son a 2004 Colorado about a year and a half ago. It's a 4 cyl, manual transmission 2WD extra cab. Truck has about 130K miles on it.
The truck ran very rough when I got it. Pulled off the throttle body and it was gummed up pretty bad. Got the TB cleaned up, installed new plugs, filters, etc. Runs like a champ now.
Here are issues I have run into:
The AC/heater fan is very loud (and ticks). I read where Chevy designed some kind of insulated cover to fit over the motor to help quiet it down.
There is a security system built into the ignition (Passlock I think its called). Every once in a while the system will trip and the truck won't start. The starter will crank but the engine won't turn over. You have to wait 5-10 minutes for the system to reset and then try again. Only happend a handful of times but it's aggravationg when it does. No idea what causes it.
The passenger side doors will not seal completely when shut. You can hear the wind whistling when you sit in the passengers seat. From what I've read this is very common with these trucks.
And finally here is the most aggravating issue by far. When the weather is wet and the temp is near freezing the parking brake cables are prone to icing up and won't release. Imagine driving home in freezing, wet conditions, parking the truck for the night, come out the next morning to take off and the parking brake won't release. Not a good start to your day. Again, this seems to be a common issue and about all you can do is wait for it to warm up and thaw out a bit.
I've never owned an S-10 so I have no point of reference, but the fit, finish and quality of materials on the Colorado is very cheap. The console armrest is an absolute joke. Whatever the lid is lined with melts into a black goo during warm weather and stciks to anything you put in it.
So, all that being said the truck has been very reliable mechanically. Can't say I've had any drivetrain issues since I got the engine tuned up. Just issues noted above.
Hope this helps.
