engine knocking noise, please help!

i just bought this 94 ford ranger with the 3.0 v6. I love the truck so far. question is, once in a while, i will hear a knocking noise when the truck is at idle. Its not a ping, and its not all the time. when it is present, its easily heard. Someone told me it could be a risk pin, not even sure what that is, and that it will outlast the life of the engine. The truck has 118,000k on it and was hoping to get twice that. is this something i should concern myself with or just continue to change oil every 3,000? Thanks for any insight to this.

If it is a wrist pin you are hearing then it could hang in there with you and hit 300k miles. But, then again it may go thrue your cylinder wall tomarrow. Who knows...my advice is take it easy on the truck and you should be ok for a while, until you can get some1 who knows what they are doing to look at it for you. Good luck.

Might just be your head gasket.