rough idle

drive805 · March 7, 2019

2016 silverado 5.3 35k miles has a rough idle any suggestions to remedy thank you in advance

1SLOW1500 · March 7, 2019

Is it cold and just started or is this over 180* engine temp?

drive805 · March 7, 2019

all the time

Sierra Dan · March 7, 2019

a "normal" slightly rough idle occurs after a long period of time or extended duration in V4 mode.

You will notice it after it switches back into V8 while at a stop light or sign. GM says its normal.

A super rough idle all the time doesn't sound normal.

Does it clear up after you get on the gas or rev it up?

Sierra Dan · March 7, 2019

MaverickZ71 · March 7, 2019

1 hour ago, Sierra Dan said:

Some people just don't seem to understand this simple concept: Most of the people who post on here looking for help, are on here because they would rather duct tape pork chops to their legs and run naked through a pack of coyotes than take a vehicle back to the dealer for anything.

drive805 · March 8, 2019

its a rough idle at all times, at start up cold ... after driving 30 minutes to work. at signals going to store , gym, gas station ,

mikedeezxxx · March 8, 2019

My 2016 5.3L is doing the rough idle thing now too. Just hit 33,000 miles. Does it when the trucks cold and hot. Thought it was from my handheld diablo tuner. Put the truck back to stock and it was even worse. Reinstalled tune and it went away for a little bit. But now it’s back. Haven’t had time to dig into it anymore. I’m gonna try and clean the cai filter and MAF sensor this weekend and see if that does anything.

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SS502 · March 8, 2019

On ‎3‎/‎6‎/‎2019 at 8:05 PM, drive805 said:

2016 silverado 5.3 35k miles has a rough idle any suggestions to remedy thank you in advance

10 minutes ago, mikedeezxxx said:

My 2016 5.3L is doing the rough idle thing now too. Just hit 33,000 miles. Does it when the trucks cold and hot. Thought it was from my handheld diablo tuner. Put the truck back to stock and it was even worse. Reinstalled tune and it went away for a little bit. But now it’s back. Haven’t had time to dig into it anymore. I’m gonna try and clean the cai filter and MAF sensor this weekend and see if that does anything.

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Do you run a catch can? Yes, I know those who need proof are going to ask for it and I can't provide that BUT I do know and it IS documented that valve "coking" due to excessive build up on the intake valves can and will disrupt airflow resulting in a rough idle. Ironically, you are both between 30-35K....just about the time that would allow "coking" to rear it's ugly head. Of course this is just a theory and just throwing it out there...food for thought.

KARNUT · March 8, 2019

Do you run a catch can? Yes, I know those who need proof are going to ask for it and I can't provide that BUT I do know and it IS documented that valve "coking" due to excessive build up on the intake valves can and will disrupt airflow resulting in a rough idle. Ironically, you are both between 30-35K....just about the time that would allow "coking" to rear it's ugly head. Of course this is just a theory and just throwing it out there...food for thought.

I have 5 vehicles 2 are over 15 years old, one is 12 years old one has a DI motor is 8 years old and a 2 year old. The all get driven weekly. No fuel additives or catch cans and not always top tier fuel. If were to act up I’d run a heavy concentrate of BG or sea foam through the tank and spray through the throttle body. Otherwise I’d figure a hard part fault or computer glitch. I used to run additives through diesels never gas. I never had a problem with gas yet and I’m old.

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SS502 · March 8, 2019

3 minutes ago, KARNUT said:

I have 5 vehicles 2 are over 15 years old, one is 12 years old one has a DI motor is 8 years old and a 2 year old. The all get driven weekly. No fuel additives or catch cans and not always top tier fuel. If were to act up I’d run a heavy concentrate of BG or sea foam through the tank and spray through the throttle body. Otherwise I’d figure a hard part fault or computer glitch. I used to run additives through diesels never gas. I never had a problem with gas yet and I’m old.

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Whatever works, works! I was just throwing it out there. Not everyone is going to have a problem obviously but they are looking for possibilities. Better to give an opinion/possible cause than to keep my mouth shut (and that is very debatable LOL) and wonder. Nobody can make me believe that this is good to have running through your intake, over your valves and into your combustion chamber...this is just 400 miles of easy driving.

KARNUT · March 8, 2019

Whatever works, works! I was just throwing it out there. Not everyone is going to have a problem obviously but they are looking for possibilities. Better to give an opinion/possible cause than to keep my mouth shut (and that is very debatable LOL) and wonder. Nobody can make me believe that this is good to have running through your intake, over your valves and into your combustion chamber...this is just 400 miles of easy driving.

My DI motor is approaching 100K miles and 9 years it still looks good. But if it starts acting up it be gone baby gone. I got my money’s worth.[emoji106]

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JimCost2014 · March 8, 2019

On ‎3‎/‎7‎/‎2019 at 8:38 AM, MaverickZ71 said:

Some people just don't seem to understand this simple concept: Most of the people who post on here looking for help, are on here because they would rather duct tape pork chops to their legs and run naked through a pack of coyotes than take a vehicle back to the dealer for anything.

Since it is kind of cold this morning (snowing), is it ok if I light my hair on fire too, seeing how I will be naked.....

SS502 · March 8, 2019

4 minutes ago, JimCost2014 said:

Since it is kind of cold this morning (snowing), is it ok if I light my hair on fire too, seeing how I will be naked.....

I did NOT need to read that....thanks Jim for polluting a perfectly good Friday morning