Originally Posted by Purplehazeir
How did you determine it was a piston rod and not a push rod/lifter noise?
I did some research on the 3.8 motor because, actually I work on old classic cars,mostly Fords and I don't know the 3.8 all that well. I searched out the most common failures for the motor that are listed on google.
Push rods, lifters as you have spoken of. Crank shaft and piston wrist pins. Harmonic balancers and belt tensioners.
I ran down the list.
Check the Harmonic and belt tensioner. I'm glad I did because the harmonic was making a very small noise,but it was not the main "Knock" noise. So I replaced the Harmonic before it got worse. The belt tensioner was already replaced about 30,000 miles ago and still work perfectly. Alt, water pump,steering,etc were fine as well
Next I started toward the harder things..
Took off valve covers,with motor running and inspected the upstairs(push rods,rockers,lifters) then I shut it down and disassembled each to get a closer look for wear. Push rods rolled straight when put on a level/flat surface. Rockers all had the same amount of wear. I used a small light/telescope to peek down on the lifters and everything was clean,no dirt/gunk. No unusual markings.
Then I put everything back together(in order), and started to think about the bottom end more,now that I inspected all the other common suspects.
If it'* a wrist pin,then a crank kit won't do much good, I would need to get a Master rebuild kit instead,because I would want to replace everything. Timing chain,cam,lifters,etc along with the new pistons and wrist pins.
Crank or wrist pin,now to determine that. I must get inside,so I've done more research for used motors in my area and have found 6 of them ranging from $350 to $1200.
But I'm Always weary on junk yard motors. I havent found any engines that are still in the car so I can hear it, I just have to go by the Junk Man'* word.
That maybe the road I will have go, just buy a cheap motor,than I can have time to tear down the original. This may seem like lots of work to most people and especially for a car that is only worth $1400 book value. But I'm a certified motorhead and this is Fun to me
I love all automobiles and it keeps my mind fresh to learn new things.
In the near future I'm also hoping to add a "Smacks" Hydro booster to it. I got the plans from smacks boosters site and built it myself. I love to tinker.
Thank you for your responses. I'm on allot of forums for many different types of automobiles and this is one of my favorites. There are so many "Good" catergories.