[73 bird]

I have a random knocking sound coming from the front of my engine. Only hear it at 1000 rpms or less. It is not a steady sound and sounds like something bumping around but can't find anything. Oil pressure is 30 lbs. at 1000 rpms and 65-70 lbs. at 2500 to 3000 rpms.

Looking for suggestions on what to look for.

[track73]

Torque converter loose? It happened to me.....

[73 bird]

Originally Posted by track73

Torque converter loose? It happened to me.....

already checked that. sounds like it's coming from the front of the engine. thanks for reply.

[grandville455]

Harmonic balancer bolt, or pulley bolts loose

[73 bird]

Originally Posted by grandville455

Harmonic balancer bolt, or pulley bolts loose

I had checked the balancer and pulley bolts when I first heard the sound.

I just took the belts off and sound was still there. Lower pulley bolts were tight but I removed it antway, sound seems to be gone(doesn't really make sense). I'm going to let engine cool off and fire it again later and see if it really went away. Sound is more noticable when engine is cold. Lower pulley appears to be out of round at low rpms but spins smooth with a little more rpms.

[HWYSTR455]

Bad plug wires, crossfire, and slightly loose rod bearings. Check the wires.

.

[73 bird]

I just fired it up and let it run from dead cold to 190 without the lower pulley and belts.The noise is not there. It was very noticeable before and not ther now. I will take the oil filter I removed last week to my buddy's shop and let him cut it open and see whats in it.

Hopefully nothing major is wrong. Just built and installed this engine last year. Runs great.

Opinions on this are welcome and appreciated.

Has anyone used these pullies?
http://www.cvfracing.com/pontiac-pul...-1985-s/48.htm

[LATECH]

Originally Posted by 73 bird

I have a random knocking sound coming from the front of my engine. Only hear it at 1000 rpms or less. It is not a steady sound and sounds like something bumping around but can't find anything. Oil pressure is 30 lbs. at 1000 rpms and 65-70 lbs. at 2500 to 3000 rpms.

Looking for suggestions on what to look for.

Check the end play at the crankshaft. Sounds eerily similar to a worn thrust on the main bearing.

[73 bird]

Originally Posted by LATECH

Check the end play at the crankshaft. Sounds eerily similar to a worn thrust on the main bearing.

How do I check the endplay?

[steve25]

Yank on the water pump pully and see how much it rocks around along with its end play.

[73 bird]

Found my problem. Balancer bolt was tight, but not tight enough. It was allowing the balancer to rock back and forth at low rpms. I called myself getting it really tight, but I didn't use a torque wrench. That carelessness could have caused me bigger problems. I will be torquing it properly this time. Thanks to everyone that offered suggestions.

[grandville455]

Originally Posted by 73 bird

Found my problem. Balancer bolt was tight, but not tight enough. It was allowing the balancer to rock back and forth at low rpms. I called myself getting it really tight, but I didn't use a torque wrench. That carelessness could have caused me bigger problems. I will be torquing it properly this time. Thanks to everyone that offered suggestions.

Good deal! Been there done that deal! That is why i told u to check it , U might want to pull it off tho and make sure the keyway isn't cracked! Mine was once it was loose and rocking on there like that.

[73 bird]

Originally Posted by grandville455

Good deal! Been there done that deal! That is why i told u to check it , U might want to pull it off tho and make sure the keyway isn't cracked! Mine was once it was loose and rocking on there like that.

Had a friend look at it with me this morning and he caught it. He also told me to check the keyway.