[ed53511]

2012 Chevy 1500 Silverado LTZ 5.3 Automatic 4Wheel Drive

Rattling Noise

Only in Drive – Never in Neutral or Park
Not during acceleration. The rattling does not exist when I am speeding up/accelerating regardless of speed.
Not during low speeds (under 5 miles (approx.) an hour or when braking). When I slow to stop signs the noise stops before I come to a halt. Even though I am not accelerating.

Sounds like 2 rocks or coins or bolts in a soup can.
Has the same tempo as the Ace of Spades on a bike wheel spoke. (If you can remember being a kid in the 40s-70s)

HELP !!!!!!

 

[ed53511]

Dealer says it is the " Cam Shaft Actuator Gear Assembly"! = $3200.00 Parts and Labor.

They removed the front drive shaft - Noise did not go away.

They replaced the Tensioner - Noise did not go away

They replaced the Alternator - Noise did not go away

They replaced the Idler Pulley - Noise did not go away

They removed the Accessory Drive Belt - Noise DID GO away.

I will let you know if replacing the Cam Shaft Actuator Gear Assembly & The Chain & Gears & Tensioner & Oil Pump results in the noise going away.

 

[RedSLEd]

Dealer says it is the " Cam Shaft Actuator Gear Assembly"! = $3200.00 Parts and Labor.

They removed the Accessory Drive Belt - Noise DID GO away.

Are they saying the cam is driven by the accessory drive belt? I'd find another dealer.

If removing the belt made the noise go away, it's an external problem, not internal.

 

[djakewill]

Are they saying the cam is driven by the accessory drive belt? I'd find another dealer.

If removing the belt made the noise go away, it's an external problem, not internal.

Agreed. That seems like an odd conclusion for them to come to.

 

[02-Z71]

Check the exhaust manifold and heat shields.

 

[ed53511]

I don't think they were actually saying the accessory belt is driving the cam. Just once it was removed the noise went away. I too found that to be an odd relationship.

However, that all being said, I did take it to another (independent) mechanic. They too confirmed the noise went away with the belt removal. They checked it to confirm it wasn't something else because they also thought it was odd. But after they broke out their stethoscope, they also heard the noise "loud and clear" inside the timing cover.

The problem was two parts. The Cam Shaft Position Actuator and The Timing Chain Tensioner were both bad. The mechanic doing the work could not confirm which was making the rattling noise. He did however suspect the tensioner.

 

[ed53511]

Check the exhaust manifold and heat shields.

Those were the first items check. As well as the catalytic converter, the drive shaft, the u-joints, the transfer case, the front axles, the brakes, and so on and so on and so on.

It was truly incredible how loud the noise was. Sure the stereo would make it go away if you turned it up enough. But the people staring at you when you drove by, validated it didn't go away even then. LOL

 

[djakewill]

I don't think they were actually saying the accessory belt is driving the cam. Just once it was removed the noise went away. I too found that to be an odd relationship.

However, that all being said, I did take it to another (independent) mechanic. They too confirmed the noise went away with the belt removal. They check it to confirm it wasn't something else because they also thought it was odd. But after they broke out their stethoscope, they also heard the noise "loud and clear" inside the timing cover.

The problem was two parts. The Cam Shaft Position Actuator and The Timing Chain Tensioner were both bad. The mechanic doing the work could not confirm which was making the rattling noise. He did however suspect the tensioner.

Definitely an odd diagnosis but I'm glad that you found somebody that was able to figure it out. Hopefully that gets rid of it for good!

 

[ed53511]

Picked up the truck yesterday. No more tin can rattling noise.