Hey everyone, having a issue. So to start, have a 1994 Silverado 5.7 350. The issue started this morning. On Friday I had replaced the serpentine belt as it was starting to whine, drove it all the rest of that day with no issues. then today on my way into work the belt started thudding once I got into 2nd gear I can get my RPMs up no issue, once I get into 2nd though I cannot get over 1500 rpms. At the same time the thumping sound from the belt comes in.


Now when I put it in park I can get the rpms all the way up with no issue and hold it there as well. So my first thought was, hey maybe I had somehow messed up the belt. Taking a look at it the belt and pulleys all appear fine, in the correct spots ect. I have no rubber missing from the grooves on the belt however on the smooth backside it does appear as the location of the burning smell. Watching the pulley system while its running I have not seen any catches, however I have found some rubber soot on the a/c pulley (smooth one).


I do not believe it is the A/C compressor, and im hoping its not the drive train pulley. Depending on who I talk to ive gotten either drivetrain pulley, a/c pulley or tensioner. Any additional advice? I plan on getting the tensioner after work today as im really thining that's it as its an original part. Thanks in advance.

 

So swapped out the tension pulley with no change. Onward to next idea. Wil keep posted.

 

Ok, seen this with spark plugs before, used put back in the box, and returned for credit at autozone. Is it possible the belt is used, and resold as new?

 

No I made sure to buy a new belt. Tried putting the old belt back on to see if it was a belt issue but it was worse. Its giving me a violent shudder when i go into drive and apply the gas. But at idle theres no issues.

 

Now you need to determine what's causing the issue, is it power steering, ac?

 

Yeah thats where im leaning next. Power stearing is still working fine when driving, so it could be ac. Im hoping its not somehow a transmission issue

 

If you think it's the transmission, but not sure, pull the serpentine belt off, runi it without it. You will then isolate the rest of the engine.

 

Will be doing that after work today. Thank you

 

Welp so im just retarded. I went off of where it sounded like it was coming from and I was wrong. Went under the truck to check some other sounds and yep, drive shaft buste out of the center support. So going to fix that now.