Hi, I have a 1990 Chevy c/k 1500 i bought it from a guy that said he used to tow a trailer with it. I recently started hearing a load noise the sounds like two pieces of metal coming from either the engine and i also hear a knocking coming from under the truck. You can hear the noises faintly or not at all sometimes when the truck is idling but when you start to give it gas no matter if its in park or driving down the road they get extremely load especially right before the gears change when the rps are high. Any ideas on what these problems could be? Thank you!

 

If it is coming from the engine itself, I would bet that it is something very bad - perhaps it is getting ready to throw a rod. It could also be something minor; perhaps a bent pushrod. It depends on how loud it is, I suppose.

If the truck is 23 years old and driven fairly hard, it may be close to quitting time for that engine. By now, it probably has a lot of mileage and you likely do not have the maintenance history available to you.

Good luck!!

 

i would almost bet that the knock under load is the main bearing's .

 

outlook not good.