99 gmc jimmy 4.3liter knock?

every 4.3l ive seen that had a "little" engine knock turned out to have the rod bearings shot my theory is that because of the oiling passages routing oil past the lifters before going to main and then rod bearings the rods get oil starved and ruin the crank hopefully that is not the case with yours another possibility is that the knock sensor is malfunctioning and the computer is shootin in to much advance very detrimental to pistons

caution!!!! do not ad give up LEAK!!!! It purely swells the seal and in some months you'd be leaking fluid like nuts!!if its a small leak its likely ok for a lengthy time period yet not solid for our surroundings. Have it look ed and se the position the leak is. Rear seal or pan gasket is a normal fix. the front pump seal potential the tranny comes out $$$ so that you're making the alternative. solid success.

Nope.

I gotta agree...nope. Sorry. But what kind of knock do you have?