I have a 2008 1500 Silvy with 53,000 miles and the engine is making a clunking/squealing noise. I know what your thinking belt or pulleys. I replaced the drive serpentine belt along with the idler pulley. But that didn't solve the problem, so I took both the A/C and drive belts off and started the truck and it is still making this noise. So now I'm stumped, I took the wife's stethoscope to see if I can pin point the noise, to me it gets louder in the bottom end, I tried each head but couldn't get anywhere near the firewall since the truck is lifted. The sound does quiet down after the engine has warmed up but you can still hear it if you are listening for it. I bought and extended warranty with the truck that covers pretty much everything that isn't normal wear and tear. But before taking it in I wanted to get some thoughts on what you guys might think it is and to see if ya'll think the warranty will even cover it or if it's just a simple fix (which I highly doubt). Here is a link to the video of the engine noise This video was taken from the driver side wheel well.

 

2008 carries the 5 year 100,000 mile powertrain warranty from gm anyway. So if it is in the engine or trans you are covered. Bring it to the dealer, let them deal with it. Just make sure you dont run a programmer or messed with the pcm calibrations.

 

I have a 2008 Silverado and at 19,000 miles I had a noise similar to that. It also had a miss. Ended up it ate up a lobe on the camshaft and messed up roller lifter on that cylinder. They told me that wasn't the first one in the shop for the same problem. They said gm had to redesign the cam in 4.8 to solve this problem.

 

crazy, my truck is still running strong and is not missing. The engine is running perfectly except for this noise. The noise quiets way down after it is warmed up, you can only hear it at that point if you are listening for it. It goes to my local mechanic tomorrow and if he thinks the stealership will fix it under warranty or my extended warranty I'll take it to GM. I'll post whatever the problem is.

 

It almost sounds like a bent pushrod.

 

How does that happen?

 

It could also be a bad lifter.

In any case, lifter, cam shaft, push rod, or whatever, your warranty should cover it. Don't wait too long though.

...btw, a bad lifter could easily bend a push rod.

 

Took the truck in and they couldn't find out where it is coming from because the noise isn't as pronounced as it was in the video. I even left it with them overnight so the engine would be cold in the morning, because as it warms up the noise quiets down significantly.

 

That's sounding more and more like a lifter. A lazy lifter will take some additional time to pump up. Also, oil thickens as it cools, and thins (flows easier) as it heats up (up to a point that is).

On an old carbed 350 I had a similar issue that turned out to be a partially clogged oil gallery. Cold (thickened) oil would flow through it, but hot oil (Thinned) would. Ended up pulling the heads, and the oil pan and cleaning the oil galleries with a set of brushes, and what amounted to long stiffened pipe cleaners. The kind with the wire barbs in them. Worked great.

The cost was 5 quarts of oil, 1/2 gallon of solvent, a couple of gallons of anti freeze, an oil filter, and gaskets for the pan, the intake, the heads, and the valve covers, and the long pipe cleaners. I already had the brushes. Took a few hours on a Saturday morning, and I also tanked the heads while I had them off. It made all the difference in the world. Less than $100.00 and the engine ran smooth and quiet after that.

Lest hope you issue is something as easy and cheap to fix.

Let us know what the garage says. - Frank

 

When I took it in, I had to actually go back and let the mechanic see the video so he knew what he was listening for. He then started up the truck and you could barely hear the noise. He probed around with his stethoscope and wanted to see if it was louder in the morning but to our dismay it was still quiet. So I have no idea what I'm going to do about it. It just sucks because I traded in my prized 05 Subaru STi in for this truck. It was very reliable and never had any problems with the car. It just wasn't a practical family car, so I got the truck and now it's having problems that no one can figure out.