[Brules]

2016 Colorado Crew Cab LT v6. 48k miles.

So I have been having this issue lately where the idle dips to 600rpm/500 rpm and it VERY rough - almost misfiring.

When at a stop or in park it will sometimes die. NO codes are thrown. No engine light.

Anyone else had this issue or have a suggestion what it could possibly be or what might fix it?

LOVE the truck, HATE this issue.

I run 89 & 93 Octane. Have run Lucas cleaner through it several times and water remover. No fix. Seems very random and doesnt do it all the time.

If you goose the gas to bump idle up to 700 - no problem. It is almost like these dumb idiot engineers choke the throttle down so much to make MPG good it starves the engine for fuel.

Would a tuner help fix this issue?

Need help otherwise I am getting rid of it lol.

PS - Car does not have issue accelerating or anything. Takes off and shifts fine etc. Just when I am at a drive through in park more often than in drive gear.

 

[Barny]

I had mine stall once while making a turn at idle. I asked a friend who's a dealer mechanic and he described your problem. He didn't say what causes it.

 

[Brules]

Ug. No codes makes it a PITA as dealership never can replicate!

 

[madcratebuilder]

I have not worked on anything newer than 2006 but there was a "minimum air rate" sort of like setting a idle speed, you plugged off a air passage and adjusted the TB.

You may need to clean the TB.

Can you put a scanner on it and see what the IAC is doing?

 

[Brules]

Whats IAC?

Yeah I have thought of taking it in to my local shop and having the TB cleaned.

 

[UnlimitedMatt]

Check out the last post in this thread.

http://coloradofans.com/forums/185-...-2015-canyon-engin-shut-down.html#post4507785

That is my thought.

 

[madcratebuilder]

Whats IAC?

Yeah I have thought of taking it in to my local shop and having the TB cleaned.

IAC idle air control, a small valve that opens or closes to control air flow and idle speed. I'm not even sure if these LGZ has a IAC, has to have some way to control air flow at idle.

The IAC's can get full of crap and cause problems, build up of crap around throttle blade can cause problems.

 

[RatRacer]

@spoonman

There was a TSB for the for a faulty/reprogramming (vacuum?) purge valve solenoid that caused this issue on LFX engines.

 

[spoonman]

@spoonman

There was a TSB for the for a faulty/reprogramming (vacuum?) purge valve solenoid that caused this issue on LFX engines.

This one?

 

[Brules]

Thanks for posting!!!!!!!! That is exactly what mine does!

 

[Brules]

Taking car in tonight to get looked at tomorrow. Hopefully this fixes it!!!!!!

When in idle it just seems to be choking itself off 24/7!

 

[Brules]

Got car back, seems like that update really helped. It will still chug a few times at idle, but hasn't died and seems to idle a TON better! Thanks again for that post!!!!!!

 

[madcratebuilder]

That could be, the puter could just open/close the throttle blade to control idle speed. My C5 vette has drive by wire but sure feels different than the ZR. I still remember the first time the nannie took over the gas pedal, scared hell out of me.

 

[plastrd]

I might bring mine in for this TSB. I leave it idle when hooking up our trailer and I noticed while I was standing back there that all of a sudden it would go from a healthy idle to a sickly sounding rasp for about 5 seconds and then all of a sudden it goes back to normal.
It hasn't stalled on me yet but it definitely doesn't sound healthy!

 

[Severe_Insanity]

I have a 2016 Colorado Trail Boss Edition (3.6L V6) with 47k miles and have had the same issue. I brought it to mechanic and he updated the ECM and so far I am not having the issue. I'll update after a week. As of now I am running it with out the pedal commander. After a week ill reinstall.
Mods Installed:
K&N Air Intake
Magflow 3 inch exhaust
Pedal Commander

 

[White016]

I say check out post #8, stalling TSB. Also, with idle problems, after a good visual inspection for vacuum leaks, or anything else, TB cleaning is a very good idea.

Don't tune with a running problem!

My 2016 with 30k miles has idled rough for about 2 seconds once a long time ago, never did it since...

 

[16WhiteColly]

This is one of the most helpful threads that I have read in awhile. Thanks.

 

[Severe_Insanity]

I say check out post #8, stalling TSB. Also, with idle problems, after a good visual inspection for vacuum leaks, or anything else, TB cleaning is a very good idea.

Don't tune with a running problem!

My 2016 with 30k miles has idled rough for about 2 seconds once a long time ago, never did it since...

Stalled out on me again after shifting to 4 low. left it running and check engine light came back on

 

[16WhiteColly]

I say check out post #8, stalling TSB. Also, with idle problems, after a good visual inspection for vacuum leaks, or anything else, TB cleaning is a very good idea.

Don't tune with a running problem!

My 2016 with 30k miles has idled rough for about 2 seconds once a long time ago, never did it since...

My 2016 did it this morning for about 10 seconds, idling in Park.

 

[White016]

My 2016 did it this morning for about 10 seconds, idling in Park.

Well hell, are you going to try any fix? According to the TSB an update fixes it. I bet mine was fixed when I did the update for the lazy throttle and trans. It's been so long ago I can't remember what happened first, rough idle or my update....Let us know.