Rough idle

Asked by Oct 20, 2015 at 05:46 PM about the 2012 Chevrolet Colorado LT1 Crew Cab

Question type: Maintenance & Repair

I just bought a used 2012 Chevy
Colorado the inline 4 cylinder LT. The
truck has a rough idle we scanned it
because the CEL has been on for
misfires in cylinder 2. I got it through
a dealer and we have them the truck
the said they switched coils from 3 to
2 and when I picked it up from them
the CEL came back on. I've changed
coils 2 and 3 and all plugs and it still
has a rough idle and CEL

5 Answers


our engine light flash?? thats a sighn of a misfire a bad coil, or plugs

1 of 1 people found this helpful.

What did the plug from the misfiring cylinder look like? Was it wet from gasoline? Wet from coolant? Dry and black? Wet and black? - Jim


No other codes indicating a IAC sensor?

1 of 1 people found this helpful.

Dirty throttle bodies. Usually cleaning them smoothes out the rough idle from what I've been told. I have the V8 model so it's not an issue for me.

I have a 2005 Colorado with the 4 cylinder engine that I've had for 11 years and it's been a great little truck. It has just less than 200K miles on it and in the last year or so the idle at start up and when coming to a stop had gotten worse and worse. I tried a number of things to fix it but nothing worked until I found on the internet about the the dirty throttle body issue. So I took off the throttle body and cleaned it up with throttle body cleaner and a tooth brush, buttoned it back up, torqued to specs, etc. and WOW what a difference! It was like having a brand new motor I shit u not! So if you have a rough idle on a truck with a lot of miles on it and you've tried the obvious things like a tune-up, new fuel filter, and it's still got a rough idle, then clean the throttle body. The difference is nothing less than amazing.

Your Answer


Looking for a Used Colorado in your area?

CarGurus has 31,655 nationwide Colorado listings starting at $1,995.


Chevrolet Colorado Experts

  • #1
  • #1
  • #3
View All

Related Models For Sale

Used GMC Canyon
125 Great Deals out of 13,139 listings starting at $3,322
Used Chevrolet Silverado 1500
2,136 Great Deals out of 167,419 listings starting at $1,900
Used Toyota Tacoma
632 Great Deals out of 43,272 listings starting at $1,500
Used Ford F-150
2,325 Great Deals out of 184,534 listings starting at $699
Used Nissan Frontier
354 Great Deals out of 21,680 listings starting at $2,000
Used GMC Sierra 1500
888 Great Deals out of 65,682 listings starting at $1,995
Used Ford Ranger
170 Great Deals out of 5,554 listings starting at $1,499
Used Toyota Tundra
470 Great Deals out of 32,492 listings starting at $1,999
Used Ram 1500
998 Great Deals out of 112,209 listings starting at $6,499
Used Jeep Wrangler
305 Great Deals out of 16,323 listings starting at $2,500
Used Chevrolet Silverado 2500HD
318 Great Deals out of 29,131 listings starting at $2,995
Used Chevrolet Camaro
428 Great Deals out of 30,916 listings starting at $3,550

Used Cars For Sale

2012 Chevrolet Colorado LT1 Crew Cab For Sale
4 Great Deals out of 77 listings starting at $8,980
2010 Chevrolet Colorado LT1 Crew Cab For Sale
36 listings starting at $8,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.