2016 Sierra Denali shake

[Dawgsten]

Hi guys, I'm new to this so please bear with me

 

Just bought a 2016 Sierra Denali 5.3 8 speed last week. Ever since new, anytime I pull away from a stop hard, I'm getting a weird vibration from the engine (or at least it seems to come from there). Something that would be similar to a faulty u joint. Here's the tricky part - it only starts to vibrate between 3800-5000 rpm, regardless of if its under full throttle or if you let off at that rpm it still vibrates.

 

I'm not talking about this thing shaking me to pieces but it's not smooth to redline which any other newer 5.3 I've driven has been. Currently the truck has about 1000km on it (~600mi).

 

I've taken it to GMC and they tell me it's not to be concerned with because I have plenty of warranty. I take this as they're too lazy to try and diagnose the problem.

 

Any help or insight would be appreciated!!

 

Dustin

[Jsdirt]

Wow ... I thought I heard all the excuses from dealers. That one is a topper!

 

Could be a defective harmonic balancer, or possibly some bent or defective belt-driven accessories (water pump, alternator, etc..).

 

These days it's entirely possible that the internal rotating or reciprocating mass has an imbalance - in that case, you'll have to live with it, unless you could prove it, and get GM to replace the entire engine. Fat chance on that, unfortunately ...

[Doug_Scott]

Hi guys, I'm new to this so please bear with me

 

Just bought a 2016 Sierra Denali 5.3 8 speed last week. Ever since new, anytime I pull away from a stop hard, I'm getting a weird vibration from the engine (or at least it seems to come from there). Something that would be similar to a faulty u joint. Here's the tricky part - it only starts to vibrate between 3800-5000 rpm, regardless of if its under full throttle or if you let off at that rpm it still vibrates.

 

I'm not talking about this thing shaking me to pieces but it's not smooth to redline which any other newer 5.3 I've driven has been. Currently the truck has about 1000km on it (~600mi).

 

I've taken it to GMC and they tell me it's not to be concerned with because I have plenty of warranty. I take this as they're too lazy to try and diagnose the problem.

 

Any help or insight would be appreciated!!

 

Dustin

 

1,000 miles is very early in the service life of the engine. Run it to the first oil change and then see if the vibration is still there. It is entirely possible it just is not broken in yet. I do not mean the traditional old school broken in, I mean the break in that is done to get all components to finally sync with each other completely. Your service writer likely "dumbed" his answer down too far. Not unusual for them to give an answer that is factually wrong, but, conveys the point he is trying to make. I would hazard a guess and say that 80-90% of customers do not have sufficient understanding of how technical things work,

[Jsdirt]

Yeah I forget about all the computer crap on these things now. Could need time to "learn" your particular driving habits.