Rough idle

[Landonz]

I have a 2013 Chevy Tahoe and it seems like there is a rough idle when in park. It has 52k miles on it so I don’t think it needs plugs or wires yet and I’ve already cleaned throttle body and mass air flow sensor. Rpms don’t seem to move much. When in drive and sitting at stop light it only moves from like 600 down to 500 but I think that is due to compresser cycling. I’ve read online and it seems that the LS engines have a slight shudder/vibration/rough idle even when brand new? Does that sound right? Anybody else have this issue?

TIA!!

 

[OR VietVet]

So, any codes. One day mine was fine and the next day I had a rough idle, more noticeable in gear under load, and a CEL and was a Bank 1 Sensor 1 Oxygen sensor. The plugs and wires were new.

 

[Landonz]

So, any codes. One day mine was fine and the next day I had a rough idle, more noticeable in gear under load, and a CEL and was a Bank 1 Sensor 1 Oxygen sensor. The plugs and wires were new.

Sorry forgot to mention that, no it hasn’t thrown any codes

 

[OR VietVet]

I also forgot to ask, was it idling smooth before and now you notice a rough idle? You said that it seems the LS engines can have a rough idle even when new. If it was smooth and now rough, then that makes no sense as an excuse for what you are experiencing. I would at least pull the plugs and post pics here. You may have a fouled plug for some reason. Get a fuel pressure reading in drive and in park to compare, after engine is warm. I also forgot to ask, problem with cold or warm engine?

 

[22YukonDenali22]

Mine has a bit of vibration at idle and in park, roms always stable at 500-550. 2008 gmc yukon denali, 6.2 L. It's always had it.

 

[BG1988]

I have a 2013 Chevy Tahoe and it seems like there is a rough idle when in park. It has 52k miles on it so I don’t think it needs plugs or wires yet and I’ve already cleaned throttle body and mass air flow sensor. Rpms don’t seem to move much. When in drive and sitting at stop light it only moves from like 600 down to 500 but I think that is due to compresser cycling. I’ve read online and it seems that the LS engines have a slight shudder/vibration/rough idle even when brand new? Does that sound right? Anybody else have this issue?

TIA!!

it's normal the compressor might be bad causing it it should idle at 595 to 610 ish



i think they have the idle set higher on the hybrid due to the "HV charging function"

 

[wsteele]

I have a 2013 Chevy Tahoe and it seems like there is a rough idle when in park. It has 52k miles on it so I don’t think it needs plugs or wires yet and I’ve already cleaned throttle body and mass air flow sensor. Rpms don’t seem to move much. When in drive and sitting at stop light it only moves from like 600 down to 500 but I think that is due to compresser cycling. I’ve read online and it seems that the LS engines have a slight shudder/vibration/rough idle even when brand new? Does that sound right? Anybody else have this issue?

TIA!!

I first detected a fouled plug (by oil) by noticing a very light miss at idle. Given your model year and relatively low mileage, I doubt the cause of any fouling would be the same as mine, but it might be worth pulling the plugs and taking a look. Mine looked like something alien was growing on the plugs.

 

[bboyce2009]

I first detected a fouled plug (by oil) by noticing a very light miss at idle. Given your model year and relatively low mileage, I doubt the cause of any fouling would be the same as mine, but it might be worth pulling the plugs and taking a look. Mine looked like something alien was growing on the plugs.

How do know what a miss would be (specifically on these vehicles?)

I recently changed my plugs and wires, and did an oil change, and something just seems off...I feel like maybe a spark plug is fouled, or maybe it’s something else that’s causing it to rough idle (stopped at a light it bounces around 500). I just don’t really know what a misfire would feel like...

 

[Fless]

A light miss would feel like a fishbite, as you're holding the fishing rod. Just a subtle nibble.

 

[wsteele]

A light miss would feel like a fishbite, as you're holding the fishing rod. Just a subtle nibble.

Exactly, explains the feeling better than I ever could. Just a slight tug, every so often.

 

[Doubeleive]

get a fuel injection service done or throw a couple bottles of injector cleaner in it for the next few fill up's this generally resolves it. I use injector cleaner in mine on a regular basis she idles smooth. Even when the ac kicks on it doesn't skip a beat

 

[BG1988]

I also forgot to ask, was it idling smooth before and now you notice a rough idle? You said that it seems the LS engines can have a rough idle even when new. If it was smooth and now rough, then that makes no sense as an excuse for what you are experiencing. I would at least pull the plugs and post pics here. You may have a fouled plug for some reason. Get a fuel pressure reading in drive and in park to compare, after engine is warm. I also forgot to ask, problem with cold or warm engine?

rough idle might be normal to an extent.... if it was misfiring the whole SUV would be shaking violently or the timing would go negative (retarded ignition timing) the CEL would be flashing.....

the rpm would drop and recover over and ever

or the engine stall out


a better way would be to check the live data stream data.. this will give more information... example at idle the converter converter temp would increase (at idle after warming up) as you will be burning fuel in the converter instead..

Less MPG

check for broken motor/transmission mounts etc..

 

[FrankU]

Did you check the gap on the plugs before the install ? They "say" the plugs are gaped at .40 and that wasn't the case when I changed the plugs.

 

[JBravo1977]

This sounds like the problem I'm having with my 2014 with 109k miles. Would a miss like that throw a code?

 

[OR VietVet]

Need to check with a scanner and see if has any history codes. History of tune related components, MAF and MAP, throttle body clean, check motor mounts....etc.

 

[wsteele]

This sounds like the problem I'm having with my 2014 with 109k miles. Would a miss like that throw a code?

Generally it will throw a code. A very slight and very occasional miss might only show up in the miss counter in a scanner and not store a code.