Noise? Rod Knock

[scapistron]

Running some errands around town and thought I heard a little ticking noise. Played around with throttle position to see if I could make it happen. Goes away while coasting. Pulled into a parking lot about 4 miles from my house and it sounded like belt squeal as I was turning. Sounds real bad. Main belts look okay, one of the tensioners has a little bounce in it, but not bad.

Drove another couple of miles down the road and pulled off into the shade and the noise was worse. This the supercharger eating itself? YouTube link below.

Engine noise

 

[alldazed]

Can’t see your u tube link but is it just the idler pulley had enough. See if you can get a mechanic stethoscope or long screwdriver on the non rotating part of the pulley and listen to it. Can put it to the supercharger snout too. Whatever it is you will hear it. I think the sc is more of a gradual process.

 

[scapistron]

"engine noise" at the end is a link

 

[jlglr4]

That sounds terrible, but it’s not the typical supercharger noise when the coupler goes bad. Your noise sounds more like a pulley to me. As mentioned above, the idler pulley is a known problem, and it will shred your belt if you don’t fix it. I’d start by just pulling the accessory belt and sc belt off one at a time and see if the noise stops.

 

[powershift]

Try to wiggle the pulley and whichever moves up/down or side-to-side is the culprit, including the water pump although those typically leak when the bearing is that bad but not always.

 

[scapistron]

Pulled the belts. Still making a bunch of noise. Off to the independent mechanic tomorrow.

 

[powershift]

Would you post back what you find out?

 

[scapistron]

Brief update on my own diagnostic work. I had a pending code for general misfire (p0300) and misfire on cylinder 3 (p0303). Pulled the plugs from that bank and stuck the camera in there. No obvious signs of the piston and valves giving each other a high-five. Did a compression test on that bank on the cold engine, #1 170, #2 165, #3 135. Not good, not terrible either.

I would like to have some words with the engineers and accountants involved with the design of the cylinder heads. Driver's side, easy to service. Passenger's side, not so much. I can only imagine how much worse that last cylinder on the v8 is.

 

[scapistron]

So that's what it sounds like when a rod bearing gives up in a SCV6.

Drained the oil, it looked fine. Cut open the filter and I was getting glitter everywhere.