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Advanced timing ****ed my pistons

If it sounds like a woodpecker when you start it cold for several seconds,it's probably a loose rod or main bearing making the noise--when oil pressure builds up it'll quiet down some..if your lucky and the bearing didn't spin in the rod or block,and the crank didn't get scored up,you may get away with just a new set of main or rod bearings..

Loose wrist pins usually make a gas engine sound like a diesel ,the sound wont get quieter or go fully away after it warms up most of the time..forged pistons are usually noisier than cast ones overall,but it shouldn't sound like its going to blow apart..spark knock can eat away the top of the piston at the edges,I had one straight six that pinged all its life and at 117,000 miles the #6 piston failed,you could see the top ring and the edge was eaten away..it used to knock every morning until it got fully warmed up,then stop..till the last day anyway,it began spewing oil out the exhaust and sounded like it was coming apart,I limped it home 15 miles..didn'r seize up,but I opted to put a V8 in its place ,not fix it,the cylinder was scored up bad..
 
diesel4me said:
If it sounds like a woodpecker when you start it cold for several seconds,it's probably a loose rod or main bearing making the noise--when oil pressure builds up it'll quiet down some..if your lucky and the bearing didn't spin in the rod or block,and the crank didn't get scored up,you may get away with just a new set of main or rod bearings..

Loose wrist pins usually make a gas engine sound like a diesel ,the sound wont get quieter or go fully away after it warms up most of the time..forged pistons are usually noisier than cast ones overall,but it shouldn't sound like its going to blow apart..spark knock can eat away the top of the piston at the edges,I had one straight six that pinged all its life and at 117,000 miles the #6 piston failed,you could see the top ring and the edge was eaten away..it used to knock every morning until it got fully warmed up,then stop..till the last day anyway,it began spewing oil out the exhaust and sounded like it was coming apart,I limped it home 15 miles..didn'r seize up,but I opted to put a V8 in its place ,not fix it,the cylinder was scored up bad..
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I am going to upload a video of the noise at startup. Give me a few.
 
Throw up a video of what it sounds like cold and hot and maybe that can help us. Either way I think you are going in to the motor but hopefully not for much more than bearings. Building an engine is simple. Just nuts and bolts.
 
Forged pistons run a tighter piston to cylinder wall clearance.... if the bores are not worn or tapered too bad you may be able to get by with a hone job and a set of hypereutectic pistons...
 
centexk5 said:
Throw up a video of what it sounds like cold and hot and maybe that can help us. Either way I think you are going in to the motor but hopefully not for much more than bearings. Building an engine is simple. Just nuts and bolts.
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Well I will stay positive and think about best case. I can't imagine worst case scenario.
 
wasted wages said:
Forged pistons run a tighter piston to cylinder wall clearance.... if the bores are not worn or tapered too bad you may be able to get by with a hone job and a set of hypereutectic pistons...
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I have to Google that one. Not familiar with hypereutectic.
 
Ideas about that?
Can everyone see the videos?
 
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I would drop the belts,,, turn the idle down some and run it again.

listen to top of engine, underneath by oil pan, and back by the torque converter.. try to narrow it down to where the noise is the worst..
 
Oil pressure is always at 60 or above.

The shop ran it and thought it was the oil pump, lifters, but eventually they said it was piston slap.
 
bottom end may be fine,,, forged pistons are going to be noisy if they didn't get the clearance right when the motor was originally bored..

again, I would drop the belts to eliminate all drive noises,, slow down the idle and take a video again...
 
wasted wages said:
bottom end may be fine,,, forged pistons are going to be noisy if they didn't get the clearance right when the motor was originally bored..

again, I would drop the belts to eliminate all drive noises,, slow down the idle and take a video again...
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I will see what I can do. I am not very mechanically inclined. Thanks for the help. When I first heard the motor it was perfect. The knock came after I drove it for 2 hours with over advanced timing.
 
Wow I would definitely drop the trans flex plate cover and check the torque converter blots and look for flex plate cracks.
It doesn't sound like an internal noise to me. I listen again at home with better speakers, than my phone.
 
If you don't have a basic set of metric and SAE wrenches and sockets, this is definitely an investment you should consider. Your truck is almost 40 years old, and these beasts required attention when new.
You can check the flex plate and remove belts with basic set of tools.
Also I would like to see all the spark plugs removed and inspected.
Your truck's paint is so nice get some fender covers too.
 
Wes Harden said:
Wow I would definitely drop the trans flex plate cover and check the torque converter blots and look for flex plate cracks.
It doesn't sound like an internal noise to me. I listen again at home with better speakers, than my phone.
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After you listen at home, please let me know. I had a custom shop or classic car shop listen to it and spent hours going over the motor and told me it was internal. He had an automotive stethoscope.
 
Wes Harden said:
If you don't have a basic set of metric and SAE wrenches and sockets, this is definitely an investment you should consider. Your truck is almost 40 years old, and these beasts required attention when new.
You can check the flex plate and remove belts with basic set of tools.
Also I would like to see all the spark plugs removed and inspected.
Your truck's paint is so nice get some fender covers too.
Click to expand...


The shop replaced all spark plugs at the same time that the timing was fixed. All brand new as of like 4 weeks ago.
 
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