wrist pin or bearing knock?

Discussion in 'Small Block Tech' started by jaystoy, Oct 9, 2008.

  1. jaystoy

    jaystoy Well-Known Member

    My 350 has a a intermitant tap from the lower end for some time now, it has not really gotten worse, but you can definatley hear it. One by one, I removed each plug and see if the knock stopped. When I got to the number 2 cylinder, the knock stopped. Do you think the bearing is bad or a loose wrist pin. Would they have 2 different characteristics?
     
  2. 87GN@Tahoe

    87GN@Tahoe Well-Known Member

    unfortunately, either way you will have to tear the engine apart
     
  3. jaystoy

    jaystoy Well-Known Member

    Okay, for the sake of argument, let's say it is the wrist or piston pin. What is the risk if I keep driving it like that? How long? What is the worst senerio? The engine has had this knock for some time now. Each time I change the oil, I cut open the oil filter, and it is always clean, always. I would think if it was the rod bearing, it would have met its demise by now
     
  4. exfarmer

    exfarmer Well-Known Member

    A wristpin can knock for years without problems, but can then suddenly let go with disasterace results. IMO anytime you have any kind of an internal knock you had better pin point the cause ASAP before something breaks.
     
  5. 70sLark

    70sLark Well-Known Member

    can you make a video or sound record clip?


    Take a laptop out there and use sound recorder???
     
  6. Fox's Den

    Fox's Den 355Xrs

    My suggestion is get the motor out and get it fixed before you lose the motor. Why make it worse than it is. If the motor lets go it might be junk after that. While that motor is knocking around it is putting more and more metal into the rest of the engine. Other parts of the motor will start to wear out. It is not a question how much longer can you run the motor. But how much longer is it going to run before it goes thru the bottom of the pan. If you have to go out to get another motor from the junk yard you don't know what you are getting then, it might be worse than yours. At least yours is still running now and isn't destroyed...yet. My motor started to knock after I had gone to the track many years ago. When I got home I tore it down and found out that the crank had cracked in two. How I made it home with the crank cracked in two is beyond me. I had to drive it for about 40 miles to get home. I made it, it is fixed and still running today.
     
  7. jaystoy

    jaystoy Well-Known Member

    Very good sound advice
     

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