[CountryBoy]

I know little to nothing about cars or trucks. My '05 Chevy Colorado is "shaking" and "bumping" hard, especially when not moving, in reverse and under 15 mph. It resembles the shaking a car makes right when it runs out of gas. Once I get it up about 25mph the problem basically disappears. I'm hoping it's nothing too serious, but am in the market for a new truck anyway, so this might just make me go for it. Any ideas or suggestions? Thanks fellas!

 

[Ingalls]

Ive heard of those 5 cylinders having problems. I think thats what the problem was, but dont know if they ever found a fix for it.

 

[mrfyslaw]

Fuel Filter...Water in gas.....I'm guessing fuel filter tho

 

[mpemt24]

Fuel Filter

That was my first thought.

 

[230grain hollowpoint]

Possible motor mount

 

[steve45]

You my have a bad cylinder head. Problem with valve seats causing missfire. H3 has same motor.

 

[buffalostink]

My 05 4 cylinder colorado did that mostly at idle and I cleaned the throttle body and it went away..

 

[Jerseybuck]

With the rain we've been having, I'd throw a set of plug wires on it. (if it has them)

 

[whitetailjunky]

Lower intake has O ring style gaskets that shrink from engine heat, common around 50,000 miles and up in some Chevys. This would cause a rough idle, and is a relatively cheap fix. Could be a bad thottle body sensor, also a cheap fix ($15-$20) and only takes about 5 minutes. It's the sensor on the throttle body, one harness and 2 small bolts.

 

[aftermath]

I had an older GMC Jimmy that ran rough at idle like you're talking about.... it was the EGR valve. It happened multiple times so I learned to fix it myself.

 

[1badshot]

Do you get a service engine light ?

Ignition misfires ,bad sensors, injector misfires (sometimes caused by plugged filter or low fuel pressure) will almost always bring on the service engine light.Sometimes a bad o2 sensor wont ,but most times it does.
If you dont have any light on ,then you have a mechanical problem...such as the bad motor .or transmission mount that was suggested.
Have your computer scanned to see what information it has stored in it. 99% of the time it will point you in the right direction.
Take it to some one before you waste time and money chasing a problem.

 

[Dubs]

could be a lot of things that make a motor run rough. Take it to a shop and have the hook up to the computer. Maybe as simple as a vacuum leak.

 

[mrfyslaw]

It's a CHEVY [wallmad][wallmad][wallmad]

 

[aarowflinger]

Where are u located I have a shop in flemington and can help. Dispite what everyone has said, those 5 cyls have not been a bad motor at all. they do however have a common problem with carbon build up in throtle body as mentioned above by someone else. this condition usually causes a surge in RMP basically at idle or in gear with a minimal load. I have a Chev 1500 and it had the same problem, cleaned the throtlebody, gave it a good fuel service and was good as new. With out seeing the truck its extremely hard to diagnose the problem but with a common problem of carbon under throtle plate , with out seeing it thats what Id say