i have a 1991 ford ranger with the 2.3l with 8 spark plugs recently iv been hearing a knocking noise when the truck is going up hill at a low rpm or when the truck is pulling a my jet ski. any ideas on what it could be?

 

Spark knock / Detonation.

 

^that could be...or the motor could be getting sloppy

 

what do you mean???

 

He is talking about the rod and main bearings inside the engine. Now as you only hear this under load i can say that it is NOT the rod/mains going out. Run some seafoam through your brake booster vacume line and see if that helps.