The motor in my dads truck started making this "knocking" sound a few months ago, I was thinking that it might be the valves hitting the valve covers but I'm not really sure so I was wondering what you guys think. I might be able to get a better recording if you guys need it. Thanks for any help.

 

When was the last time the valves were adjusted?

 

They've never been adjusted that I know of but the engine was re-built once.

 

Um yeah, valves should be adjusted about every 20k, depending on usage.

Aaron

 

Hard to tell. Try to get better sound, pop the belt off for the recording so you don't get fan/air noise. Also blip the throttle a few times for us.

 

That sounds more like a rotating gear noise than a rap. Like the pump or timing gears. Not a good sound for sure. Its hard to tell.???

 

ok I'll try to get a better sound some time later today

 

Well I didn't get to get the sound without the belt yesterday but I got it today so here it is. also I pulled the first valve cover off and i didn't see any wear on it.

 

We will pray for you!

 

In the video, it sounds too fast to be in the valvetrain IMO.

Is the sound coming from the top end? Front?

 

That is a weird one but, Has the kdp been killed. Now I know you said it has been like that for a few months, but on a long road trip mine made a noise like that and come to find out it was the dolw pin riding on the gear tryin to get out of the gear cover.
Justin

 

I agree. Its to fast for a rod or piston. I guess I would start in the timing cover and go from there.

 

Yeah, it's not combustion or bearing noise. Something is grinding itself to death. I bet it's the vacuum pump bearing.

 

The vac. pump runs at crank speed, right?

 

Yes, it does.