Think I've got a rod knock...how to check it?

Thanks for all the help guys!!! I was really in the dumps this morning about it. Now I have a few things to try. And great website too.
Thanks
Ryan

 

Sounds like it might be piston slap or wrist pin, most of all rod knocks I have heard I said "that sounds bad shut it off!!" It's deep seated and will always be there (also low or flucuating oil pressure). It seems to me that the clue is "as soon as I release the throttle" kind of like a dirt bike when cold. I've been wrong before, but the only way to figure it out is to tear it down. Another thing you said is you were tuning the fuel system, do you think it went lean at any time, lean conditions can damage pistons. Bottom ends usually go out when you did something bad like low oil level or running while Jeep is upside down or over reving the engine trying to impress someone, or just plain old worn out. I would not run it with any internal noise, unless you have a spare engine laying around, or have a old Ford as a plow truck!!

Joe

 

awesome web site. put a few more tools in my bag-0-trix.

keep us posted on whatcha find with your jeep. wish i were there to help out, or just listen and give tips and ask questions..=)

 

Update...After get out my stethescope and pokin around. I could not pin down a noise on the engine...the bottom end sounded fine. Alittle valve noise but nothing with the same frequency. So I got out my timing light and checked the timing...5 btdc. Right on. I then decided for the heck of it to check to see if I could reproduce it the same way with the vacume line unplugged...it was barely there. I put the vacume line on and there it was stronger. All along I was freakin out and it was just pinging/detonating. Never thought it could detonate with no load. The fuel injection(leaner mixture 14.7:1 and the 9.0 compression ratio are probably the culprit. Going to change the advance springs on the HEI and put on a adjustable vacume diaphragm on. I will probably adjust the fuel tables to run alittle richer too. Again everyone thankyou for the help. This website is awesome!
Ryan

 

Great to here you are back in bussiness Ryan keep plugging away and keep us updated.

 

actually, we gave suggestions and you did a world of trouble shooting for us..=)
if i run into the same prollem, i will scroll back to this post..lol
take care