'96 Chevy Silverado started making funny noise

On the way back from the feed store, loaded down with 20 bales of timothy. A roaring sound – at first I thought the car was dragging something. Really loud in 1st and 2nd gear. Engine light not on. Any ideas?

I got nothing. Things get really weird when you’re running heavy.

Yes, I know from this post it’d be just about impossible to give any sort of diagnosis, but I thought I’d put it up anyway. This truck has hauled hay many times before. We took it to the shop last night – the truck made some noise starting out (3 hours after I got back from the feed store), then the noise stopped shortly thereafter. Hubby was driving the truck so that he could hear the noise too. At the shop the truck hasn’t made any noise again. They’re going to try running it hot to see if they get anything.

There’s almost no information to work with here.
Perhaps it’s just a hole in the exhaust.
What’s timothy?

It’s hay for horses.

Naturally the truck didn’t make any noise for the shop guys. The truck is making a lot more noise after that evening in first gear than it used to.

There isn’t a lot to go on but here’s a stab- a fan clutch is used on some versions of your truck. If you have one and it fails, it can keep the fan engaged even when it’s not supposed to be. The fan makes a loud roaring sound when the engine speed is high like right before it shifts to the next gear. When you take it to the repair shop, it’s unloaded and not being worked as hard so maybe that’s why they couldn’t reproduce the problem- assuming they even took it for a spin. Maybe they didn’t even drive it. Anyway, that’s what I would check first if your truck has this type of clutch. You can look at the front of the engine to see if the fan is mechanically connected to the engine or if it is an electric fan with no connection to the engine. If it’s connected, then it has a clutch and it should be checked to make sure it is working correctly.

I second TT’s idea on the fan clutch (which this truck definitely has). “Roaring” is an apt description of the noise a failing fan clutch makes.

Timothy = a species of grass or hay. It is one of the kinds with big seed heads.

I agree with the fan clutch diagnosis. Here’s what the little critter looks like, and they’re easy to check and change out.

If that gave out would it screw up the transmission?

No but it could significantly load down the engine by making it work much harder. Why do you ask? Is the actual problem that the trans is slipping and the engine rpms are going way higher than they should?

RPMs never went higher than they should have, but the transmission did give out. The guy at the shop (truck had to be towed there) said that the transmission was full of metal.


BTW- make sure they flush the transmission cooler in the radiator BEFORE they install and run it with the new/rebuilt transmission. All that junk has been circulating in the transmission and its cooling system. If they don’t flush the cooler, it will dump its load of junk into the new trans and likely shorten its lifetime. This is something they should know and do but it never hurts to keep an eye on them to make sure it gets done right.