Is there such thing as out of balance (engine, AC fan, etc.) that cause rough idle?

[smokey_mountain]

No kidding, I will clean TB at this point by taking it off the truck. I bought new gasket for TB as well just in case. This Gen V are Throttle by Wire, so I will be the guinea pig for this forum. Maybe I should do a video to recoup some of the money I wasted trying to fix this truck while it is in full warranty I am reading that varnished oil vapors is what I need to look for on the TB and butterfly to clean. I agree at 15K there should not be much to clean but... DI engine execution by GM is just low quality of design and build. Speaking from experience I cleaned MAP and MAF sensor last night using CRC MAF cleaner, noticeably better idle today. Not 100% but I think much better. I need to run it more on a hot day but from what I can tell there is improvement, so I am chasing the right problem somehow - fuel + air.

 

[OR VietVet]

So, you are not replacing the MAP like you said?

 

[smokey_mountain]

Yes I have ordered the new MAP it just takes some time to get it. I have cleaned the existing MAP for now.

So, you are not replacing the MAP like you said?

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[smokey_mountain]

False positive on the cleaning MAF and MAP, drove quite a bit today and same old shaking flutter trembling is as bad as before. Not sure why it was better for a brief period but cleaning did not help.

 

[Doubeleive]

I have a L83 throttle body I can sell I replaced mine with a shaved one, it has about 26k on it

 

[Doubeleive]

L83 idle with the AC on, virtually no wiggle you can see the end of the dipstick wiggle a little but even holding my phone against the frame there is no video shake and the idler doesn't even wiggle

 

[mikeyss]

L83 idle with the AC on, virtually no wiggle you can see the end of the dipstick wiggle a little but even holding my phone against the frame there is no video shake and the idler doesn't even wiggle

Your video reminded me of one thing I like better about the K2 vs the GMT900 engine bay.... You have PWM fans instead of just the HI/LO fans of the GMT900 . Even with your a/c on, your fans run much slower and quieter than my K5L fans. Come to think of it, I don't think I have ever heard a K2 style truck/suv run on hi.

 

[Doubeleive]

Your video reminded me of one thing I like better about the K2 vs the GMT900 engine bay.... You have PWM fans instead of just the HI/LO fans of the GMT900 . Even with your a/c on, your fans run much slower and quieter than my K5L fans. Come to think of it, I don't think I have ever heard a K2 style truck/suv run on hi.

i think these fan motors are brushless on the k2xxx that alone makes a lot of difference, there is no 500w/700w option only a option for a thicker radiator with the towing package
7/8" is regular and 1 1/8" is the enhanced cooling

 

[smokey_mountain]

There is no doubt that even Gen V DI engines can run smooth as butter, but there are also many that rough idle all the time.

 

[Bob2C]

There is no doubt that even Gen V DI engines can run smooth as butter, but there are also many that rough idle all the time.

Do you by any chance have the max tow package? Duel radiator fans. I have that and wondering if there is a connection there?

 

[OR VietVet]

This is not the first thread on this forum about these engines idling rough. There are likely some TSB's related to it but no recalls because it is not a danger.

 

[Bob2C]

This is not the first thread on this forum about these engines idling rough. There are likely some TSB's related to it but no recalls because it is not a danger.

All over the Sierra forums as well going back to last generation as well

 

[smokey_mountain]

Not sure how to tell but from the windows sticker I do not see the max tow mentioned. It has 7300 lbs. rating.

Do you by any chance have the max tow package? Duel radiator fans. I have that and wondering if there is a connection there?

 

[Bob2C]

Not sure how to tell but from the windows sticker I do not see the max tow mentioned. It has 7300 lbs. rating.

It should say on the sticker. I think max tow package can go up to 8400lbs. I just noticed the other day when I changed my oil that there are dual fans. Don’t know if that standard across or just for the tow package. Trying to see if there are similarities in packages because of the rough idles. Just throwing stuff out there


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[smokey_mountain]

Makes sense, I will double check for sure tomorrow. To match your setup, I have ordered Airaid Jr to try.
It is interesting that there are no complaints of rough idle on 2019-20 vehicles, trucks and SUVs.

It should say on the sticker. I think max tow package can go up to 8400lbs. I just noticed the other day when I changed my oil that there are dual fans. Don’t know if that standard across or just for the tow package. Trying to see if there are similarities in packages because of the rough idles. Just throwing stuff out there


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[smokey_mountain]

This is what Arbitrator decided. Rough idle is "within GM spec" as it not a safety risk. I am reading more and more often these days, that GM and dealers are using "within GM spec" execute for those items that are not safety risk but expensive to diagnose and fix. Interesting that "within GM spec" is not challenged anywhere, it makes no sense to me that manufacturer can just appoint the "spec" and hide any non-safety defect in that bucket...

This is not the first thread on this forum about these engines idling rough. There are likely some TSB's related to it but no recalls because it is not a danger.

 

[Bob2C]

Makes sense, I will double check for sure tomorrow. To match your setup, I have ordered Airaid Jr to try.
It is interesting that there are no complaints of rough idle on 2019-20 vehicles, trucks and SUVs.

Very interesting. Make sure when you install the air aid jr to wipe the ends of the tube and rubber piece that connect to air box and throttle body with alcohol. I found them to have some oily residue probably from manufacturing. I got this advice from another person reading their review. I guess some had issues with it not sealing around throttle body. I have no issues.


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[smokey_mountain]

Thank you for the tip, indeed. I will make sure. I will try all that I can within reason to get the idle to be smooth. When I cleaned the MAF and MAP, idle was smooth for the entire 2 hours of driving yesterday, but today - back to rough... oh, well.

Very interesting. Make sure when you install the air aid jr to wipe the ends of the tube and rubber piece that connect to air box and throttle body with alcohol. I found them to have some oily residue probably from manufacturing. I got this advice from another person reading their review. I guess some had issues with it not sealing around throttle body. I have no issues.


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[Bob2C]

Thank you for the tip, indeed. I will make sure. I will try all that I can within reason to get the idle to be smooth. When I cleaned the MAF and MAP, idle was smooth for the entire 2 hours of driving yesterday, but today - back to rough... oh, well.

Now that’s very interesting. You may be onto something. Maybe take one out at time and clean them again. See which one will make idle smooth???

 

[smokey_mountain]

another interesting observation only 5.3 seem to have rough idle, 6.2 not much at least in 2019-20 lineup.