mdes0

I ran mine without the main belt on and it still made the noise. I also had hoped it was the idler pully. I wasn't able to get the ac belt off at the time though, had just had shoulder surgery. Could be the bearings in the compressor I suppose.

I pulled the main belt off mine and started it up. Still made the noise, so it's not the idler pulley. I wasn't able to get the ac belt off, dam stretch belts are a ******, even worse when your down to one arm. Had shoulder surgery a week ago. Guess I'll be going to the dealer for this after all.

I beleive I may have found the chirping issue. I think it is the idler pulley. I sprayed it with wd-40 and the chirp went away for a while. I'm now debating whether or not to bother with the dealer or just swap out the part. Its only 35 bucks and one bolt so not sure it's worth the time to bring it to the dealer... Anyone had the idler pulley replaced to eliminate the chirp and not had it work?

My 19 LTZ 6.2 has been making this noise for a while and has been getting worse. I thought it was the high flow cat y pipe I installed. Glad to hear it's not, but not looking forward to dealing with the dealer...

Yes, on a 19. No CE light, no computer issues

I didn't do headers but I did swap out the y pipe. If you take a look at the factory one the crossover pipe from the drivers side of the motor is significantly squished, I am assuming for clearance. I am not worried about clearance so I went with a y pipe with high flow cats from AFE. Nice piece, but if you do go this route I would recommend ordering an extra set of exhaust manifold studs as the OEMs on the 19s strip ridiculously easy. Get the studs for an 18 from autozone or something. I haven't tuned the truck, I did however disconnect the battery so it would re-learn, and I haven't replaced the muffler yet but feels smoother and much more responsive off the line and down low. It will smoke the tires off the line into 2nd all day long. I plan to replace the muffler with a borla and then get the GM cold air setup so I can get the GM performance tune.

Yes, mine drops when the temps get under 35 or so and it drops quick. LIke from 18ish to 15. Has done this ever since GM did the catching on fire recall. From what I understand to solve the problem they richened the mixture to keep the exhaust cooler. Evidently running really lean was the main cause of the fires as the exhaust manifolds would get so hot while idling plastic that was near by would melt and then catch on fire when it finally dripped on the exhaust.

My cab had a few mystery water leaks as well. First it was the satellite antenna, then it was a pinch weld in the roof panel that had burned through the metal when it was built! I got lucky and had a tech that didn't give up. They replaced the sunroof seals, readjusted and it still leaked when it rained hard. The tech took a chance and pulled back the door seals along the roof edge, saw nothing wrong but still grabbed a hose and ran water over the roof with the seal pulled back. He noticed a little whirlpool form where water was getting through a pin whole in a pinch weld. It would take a lot of rain since it had to fill the roof panel before it would get in the cab and leak down the b pillar. Anyway, a little seam sealer on the hole and no more leak.

HEy Folks, I've kept up with this topic for months so I know how previlent this issue seems to be so imagine my suprise when I was reading through the complians for the 2014 Sierra at http://www-odi.nhtsa.dot.gov/ and only found one vibration compliant. Why aren't people logging this problem with the government?

Have you noticed any improvements since installing? Any MPG increase?

Looking to trade someone for a black 2014 Sierra rear bumper with corner steps and rear senors in the NH area. Matt

So I accelerated at full throttle the other day and found that my truck also vibrates through 1st gear. Actually stops vibrating shortly before the shift to 2nd. Leads me to believe its in the trans.

I'll try that later today. If that is when it is happening to you then I would suspect a bad u-joint or incorrectly installed joint. I say that because when you accelerate hard like that the rear end twists the pinion into a higher angle which could make an existing problem worse. Will let you know what I find.

Mine does not have any acceleration vibration. No vibration at all actually. All Terrain crew cab with 3.42's and 20's with crap goodyears. That one could be loose plug wire I bet.

My dealer had to balance my tires at 12 miles. It had the vibration so I refused to accept delivery until they resolved it. Dealer never mentioned this 500 mile thing.