Hey,

I have noticed this over the past few days. When I start my truck, there is a grinding noise, similar to rusted metal rubbing together, or at least thats the best I can describe it.

When parked, the noise happens for a second, and disappears for a second. When accelerating, the noise becomes much more frequent. (happens for 1/4 second, gone for 1/4 second, untill it just sounds constant)

Also, I have noticed that my engine consistently revs up to 3000 rpm before changing gears. Is this common, or maybe even related to this noise?

Got the next couple days off, going to pop the hood and see if there is anything I can see, or even pinpoint where exactly the sound is coming from.



thank you,

-nate

 

good idea. Start with releasing accessory drive belt. You can run engine short time without it. If noise is still there, you have a real problem.
Not there, spin all the pulleys.

 

how difficult would that be, and what tools would I need?

 

3/8 drive ratchet in square hole in belt tensioner arm.

Need help.. have any friends who work on their own cars? Better to feel comfortable.

To find the tensioner, press hard on the belt and watch for the pulley that swings. That's the tensioner. You only need take the belt off it or the idler between the two top pulleys, dont need take belt all the way off.

 

When the sound happens is the A/C or windshield defroster on? It might be the clutch on the A/C compressor. A 1/4 second is a very short time but it may only grind a bit when the compressor starts up until it becomes constant.

As for the reving engine is that the 1st - 2nd gear shift? Mine always reved higher under moderate & up acceleration then shifted hard into 2nd. Then I got the trans rebuilt & upgraded.

 

I think Rotti is correct. Do as I said and pay close attention to the compressor pulley. Spun, it should not sing nor should it move back and forth any. Put pressure on, if it rubs anything while turning.. you must replace the clutch pulley assy immediately or you may be replacing the entire compressor.
If it's the clutch itself grinding, it's too late. see if the compressor turns okay by turning the very front piece by hand.
What you are hearing may well be the pulley rubbing the clutch coil due to a sloppy worn bearing or broken pulley-clutch web. Look also for metal dust directly behind pulley and on the connector directly behind it.

Sad but true.

 

Like most on here it's our personal experiences that may be the answer another needs but doesn't necessarily want to hear. At least it helps narrow down possibilities.