Rough Idle = New Motor Mounts?

[diyer2]

15 minutes ago, jtjohnston said:

OK no offense but since you work for  GM I will disregard anything you say.

 

Do you realize what a dumb comment this is?

 

[Grumpy Bear]

1 hour ago, jtjohnston said:

OK no offense but since you work for  GM I will disregard anything you say.

 

Now there's some well grounded logic. Wonder what makes people say things like this? 

[Justin101714]

justin i dont have the rough idle problem but when it switches to v4 mode the truck vibrates really bad , i dont have any codes or vibrations except v4 mode would these new mounts fix this problem. it is a 2014 5.3 ccsb 4x4 

Sorry I’m late, I would say yes. But you need to verify the E1 vibrations with a picoscope. If you want to just sort of shotgun it, try the mounts. I would say about 80% of vibrations on these trucks and SUV’s with the vibration at idle in drive is the mounts grounded internally.


Sent from my iPhone using Tapatalk

[2017Z]

Mine was verified with the picoscope and exact issue described in the TSB. Still does it like nothing has changed. Any suggestions. Don’t know how it fixed it for 80%of trucks but mines the exception. 

[15 Z71]

On 3/12/2018 at 4:08 PM, Justin101714 said:

Yes, I work for several dealerships throughout the south east.


Sent from my iPhone using Tapatalk

I appreciate you offering advice on things. As I'm sure some other forum members do.

[Justin101714]

I appreciate you offering advice on things. As I'm sure some other forum members do.

I do what I can. [emoji1417]

 

 

Sent from my iPhone using Tapatalk

[Mileguru]

10 hours ago, diyer2 said:

Do you realize what a dumb comment this is?

 

Agreed. In situations like this, I usually look at the number of posts (just like when I look at people who post a review on Yelp).

So lets count them up:

jtjohnston = 7

Justin101714 = 700

[sk]

On 3/14/2018 at 1:50 PM, Justin101714 said:

 

Doesn’t hurt my feelings one bit man. You’ll just continue to have broken shit. I’ve contributed in favor to a lot of forum members on their problems with their trucks and SUV’s. Is everyone going to agree, no.....but that’s okay. We’ll just keep things moving and you’ll get left behind. Do everyone a favor though, go trade your truck in and get something else from a different manufacturer so we don’t have to see your pissing and moaning. Trust me, the loss would be beneficial to GM. They’ll just sell it to someone else who’ll like the truck and organization behind the truck.


Sent from my iPhone using Tapatalk

 

Justin is the real deal.

He has contributed lots of honest answers based on experience to these forums when he didn't have to.  He has also helped tons of us through PM's.  If you don't want to listen to him then don't.  I for one will continue to follow his posts.

 

Thanks for all the help Justin ...

[Justin101714]

Mine was verified with the picoscope and exact issue described in the TSB. Still does it like nothing has changed. Any suggestions. Don’t know how it fixed it for 80%of trucks but mines the exception. 

 

 

Rough idle in drive or all the time? Do you have a copy of your invoice that shows the technician notes. I’d love to see them.

 

 

Sent from my iPhone using Tapatalk

[2017Z]

Drive, after the engine is warm. Idle sets at about 500-490ish and shakes. Sometimes coming to a stop it vibrates so bad snd the idle drops to about 300 for about 2 second and feels like it will did. Exactly like the TSB. Cold starts when idle is at 6-700 it’s smooth as silk. 

 

here is the copy of the work order listing the parts they used. It did not correct anything. 

 

I have alsi tried CRC intake cleaner as others have suggested. Nothing. 

[Justin101714]

Drive, after the engine is warm. Idle sets at about 500-490ish and shakes. Sometimes coming to a stop it vibrates so bad snd the idle drops to about 300 for about 2 second and feels like it will did. Exactly like the TSB. Cold starts when idle is at 6-700 it’s smooth as silk. 
 
here is the copy of the work order listing the parts they used. It did not correct anything. 
 
I have alsi tried CRC intake cleaner as others have suggested. Nothing. 

I’m going to assume you have no other issues present, no check engine light, no tuning done, etc....

Also, what’s your particular engine, trans setup? When it’s rough idling, does it have a random stumble during that time or is it rhythmic?


Sent from my iPhone using Tapatalk

[2017Z]

Correct. No other issues. Just this. I have a kn CAI and CORSA exhaust but the rough idle was there before I installed those. No tune

 

Not sure what you mean by stumble unless your referring to the inter it’s the shake during rough idle. My kids call it the butt massage and wife says it feels like to going to stall. 

 

5.3 with 6 speed. The ones everyone seems to complain about. I had a 2014 4.3 with 6 speed prior and never had this rough idle 

 

 

[Justin101714]

Correct. No other issues. Just this. I have a kn CAI and CORSA exhaust but the rough idle was there before I installed those. No tune

 

Not sure what you mean by stumble unless your referring to the inter it’s the shake during rough idle. My kids call it the butt massage and wife says it feels like to going to stall. 

 

5.3 with 6 speed. The ones everyone seems to complain about. I had a 2014 4.3 with 6 speed prior and never had this rough idle 

 

 

So it’s there whether it’s in drive or not and it does it all the time or only when the engine is cold or warm?

 

 

Sent from my iPhone using Tapatalk

[Justin101714]

I’m thinking your mounts are actually contacting the frame on the most inward bolts. I’d try to have the mount shimmer on the inside 2 bolts closest to the engine. A couple washers should do. Try this an give us an update. I’ve only had to shim a select few.


Sent from my iPhone using Tapatalk

[2018GMC]

I’m thinking your mounts are actually contacting the frame on the most inward bolts. I’d try to have the mount shimmer on the inside 2 bolts closest to the engine. A couple washers should do. Try this an give us an update. I’ve only had to shim a select few.

 

 

Sent from my iPhone using Tapatalk

 

I just picked up my 2018 slt 6.2. See signature for details. Had a rough idle since I left dealer. Runs excellent otherwise. Currently have 1800 miles and 40 hrs on engine. Ran a few tanks of premium. Still get the chug that shakes seat at idle.

 

Give more time for brake-in? Time to contact dealer? Is it better to print TSB if so what’s the number of just show and tell?

 

Also been reading about a bad head casting? My truck was built 12/7/17. Hopefully missed that but just checked all fluids and all are normal but coolant overfilled.