14 Tahoe Rough Idle + other symptoms

[J-14OverlandPjct]

Hello all, I am new to the forum and have done some digging around but am unable to find a similar discussion with the issue I am dealing with. I recently bought a 14 Tahoe 2 weeks ago as an overland build project, and have since replaced spark plugs, plug wires, air filter, oil change, and had the injectors cleaned. I am currently trying to get rid of the rough idle it has, which is apparent from cold startup all the way to operating temperature. Idle ranges from 600-700 when at temp (1100 cold?) when these symptoms occur (every few seconds I get a stutter-like feeling. Not major but enough to cause concern) I recently drove the truck to Texas and back (12 hour trip one way) after the mentioned maintenance and it performed fantastic. Rough idle is still present, as well as dimming/flashing headlights under load/acceleration + engine feels slightly underpowered. The alternator is new from previous owner, and I have had the battery, alternator, and starter tested and all have passed. The interior switches are also hot to the touch if I drive anything over an hour. Curious to see what you all think! Truck has 125k on it but is in fantastic condition, no leaks or obvious concerns. I also plan on keeping a forum open on build progress!

 

[J-14OverlandPjct]

Hello all, I am new to the forum and have done some digging around but am unable to find a similar discussion with the issue I am dealing with. I recently bought a 14 Tahoe 2 weeks ago as an overland build project, and have since replaced spark plugs, plug wires, air filter, oil change, and had the injectors cleaned. I am currently trying to get rid of the rough idle it has, which is apparent from cold startup all the way to operating temperature. Idle ranges from 900-1250 when these symptoms occur (every few seconds I get a stutter-like feeling. Not major but enough to cause concern) I recently drove the truck to Texas and back (12 hour trip one way) after the mentioned maintenance and it performed fantastic. Rough idle is still present, as well as dimming/flashing headlights under load/acceleration + engine feels slightly underpowered. The alternator is new from previous owner, and I have had the battery, alternator, and starter tested and all have passed. The interior switches are also hot to the touch if I drive anything over an hour. Curious to see what you all think! Truck has 125k on it but is in fantastic condition, no leaks or obvious concerns. I also plan on keeping a forum open on build progress!

It’s also worth mentioning I have replaced both upstream 02 sensors due to codes thrown, and no CEL since.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me in this area will chime in.

 

[J-14OverlandPjct]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me in this area will chime in.

Thanks Joseph! Excited to get some good discussions going.

 

[Doubeleive]

Hello all, I am new to the forum and have done some digging around but am unable to find a similar discussion with the issue I am dealing with. I recently bought a 14 Tahoe 2 weeks ago as an overland build project, and have since replaced spark plugs, plug wires, air filter, oil change, and had the injectors cleaned. I am currently trying to get rid of the rough idle it has, which is apparent from cold startup all the way to operating temperature. Idle ranges from 600-700 when at temp (1100 cold?) when these symptoms occur (every few seconds I get a stutter-like feeling. Not major but enough to cause concern) I recently drove the truck to Texas and back (12 hour trip one way) after the mentioned maintenance and it performed fantastic. Rough idle is still present, as well as dimming/flashing headlights under load/acceleration + engine feels slightly underpowered. The alternator is new from previous owner, and I have had the battery, alternator, and starter tested and all have passed. The interior switches are also hot to the touch if I drive anything over an hour. Curious to see what you all think! Truck has 125k on it but is in fantastic condition, no leaks or obvious concerns. I also plan on keeping a forum open on build progress!

hot/warm to the touch switches may or may not be normal depending your sensitivity to such things, they do have small lights in them so getting warm may be normal I never really paid much attention to it myself
other than that flickering lights and even the rough idle could be a poor ground issue. I would start by checking and cleaning any and all grounds you can find. disconnect them and clean them even if they look "ok" these vehicles are very sensitive to voltage. I would also check them with a meter and be sure each ohm's out to zero or very very close to it. 0.1 0.2 is expected sometimes, maybe even 1 or 2 ohm's depending on the distance but anything greater than that might need to be addressed
other things to possibly address are the maf and throttle body

 

[J-14OverlandPjct]

hot/warm to the touch switches may or may not be normal depending your sensitivity to such things, they do have small lights in them so getting warm may be normal I never really paid much attention to it myself
other than that flickering lights and even the rough idle could be a poor ground issue. I would start by checking and cleaning any and all grounds you can find. disconnect them and clean them even if they look "ok" these vehicles are very sensitive to voltage. I would also check them with a meter and be sure each ohm's out to zero or very very close to it. 0.1 0.2 is expected sometimes, maybe even 1 or 2 ohm's depending on the distance but anything greater than that might need to be addressed
other things to possibly address are the maf and throttle body

I’ll attack the MAF along with ground connections first, hoping this solves my issues. As far as the warm/hot switches, I’m not going to be cooking steak on these things but the rear climate control panel gets hot enough to make me think internal parts may be getting damaged, especially on long drives. Do you recommend replacing the MAF or clean and re-install?

 

[Doubeleive]

I’ll attack the MAF along with ground connections first, hoping this solves my issues. As far as the warm/hot switches, I’m not going to be cooking steak on these things but the rear climate control panel gets hot enough to make me think internal parts may be getting damaged, especially on long drives. Do you recommend replacing the MAF or clean and re-install?

the rear climate controls are known the get warm, I thought you meant like the drivers window switches or something like that.
for the maf and throttle body I would trying cleaning first, that's rather easy and the cleaner's are only a few bucks for a spray can at the auto parts store or even walmart
they are seperate cleaners
1 is for maf
just take it off and spray it all over real well and let it sit and dry while you do the TB
1 is for throttle body
use a lint free cloth and don't press h-ard (hard is filtered lol) on the throttle body butterfly just go easy on it.
after reassembly be sure everything is on properly and fairly snug, doesn't have to be torqued to any special amount, but if it is not on correctly it can lead to unmetered air entering

 

[Doubeleive]

when I bought my 12 it didn't have any idle issue's but it did have a intermittent slight "stumble" on acceleration, more annoying than anything so I changed it to a ls3 throttle body and it resolved the issue.

 

[Miami-Dade]

Hello all, I am new to the forum and have done some digging around but am unable to find a similar discussion with the issue I am dealing with. I recently bought a 14 Tahoe 2 weeks ago as an overland build project, and have since replaced spark plugs, plug wires, air filter, oil change, and had the injectors cleaned. I am currently trying to get rid of the rough idle it has, which is apparent from cold startup all the way to operating temperature. Idle ranges from 600-700 when at temp (1100 cold?) when these symptoms occur (every few seconds I get a stutter-like feeling. Not major but enough to cause concern) I recently drove the truck to Texas and back (12 hour trip one way) after the mentioned maintenance and it performed fantastic. Rough idle is still present, as well as dimming/flashing headlights under load/acceleration + engine feels slightly underpowered. The alternator is new from previous owner, and I have had the battery, alternator, and starter tested and all have passed. The interior switches are also hot to the touch if I drive anything over an hour. Curious to see what you all think! Truck has 125k on it but is in fantastic condition, no leaks or obvious concerns. I also plan on keeping a forum open on build progress!

Welcome from NYC!

Moved you here from 2021+section

 

[J-14OverlandPjct]

the rear climate controls are known the get warm, I thought you meant like the drivers window switches or something like that.
for the maf and throttle body I would trying cleaning first, that's rather easy and the cleaner's are only a few bucks for a spray can at the auto parts store or even walmart
they are seperate cleaners
1 is for maf
just take it off and spray it all over real well and let it sit and dry while you do the TB
1 is for throttle body
use a lint free cloth and don't press h-ard (hard is filtered lol) on the throttle body butterfly just go easy on it.
after reassembly be sure everything is on properly and fairly snug, doesn't have to be torqued to any special amount, but if it is not on correctly it can lead to unmetered air entering

Thanks! I’ll knock these out this week and update on how it’s running!