HUNTER39

I have an 87 350 sbc rebuilt since rebuild motor has knocking noise at 1-2 shift and 2-3 shift, if I apply a little pressure at idle, in park to the serp. belt knock can be heard. I have put new bearings no change, engine runs great, 50-60lbs oil pressure, no over heating,engine stock comp, towing cam, changed from electric in tank to mechon block fuel pump. I really dont want to pull engine again for nothing any Ideas to what problem may be? Thanks Shannon

cburge

Check for loose torque converter or cracked flywheel maybe?

Scooterz

The sound,,, tell us more. Could it be timing/pre-ignition when a load is on the motor?

cepx111

Ok this phrase in your original post has me a bit confused>" if I apply a little pressure at idle, in park to the serp. belt knock can be heard"

Is it a belt noise your refering too? Or is it a metalic noise coming from your engine?

If its a belt noise then just put alittle silicon spray on the belt and or check for a bad idler pulley, but if it's coming from the motor you need to describe it better I.E> light valve train tapping like a lifter or loose rocker arm or is it a lower end knocking noise like a spun bearing.
Please elaborate, more info and a better description of the noise is needed. JMO
Cp

HUNTER39

Well to tell you the truth I am also confused. The noise sounds like a dead knock in bottom end but like I said we changed the bearings but old bearings were fine. The noise is noticable on trans shift and when some tension is applied to the tensioner when engine is idleing. Also removed balancer and noise was constant with out balancer at idle. I hope this helps. Thanks Shannon

Racefab57

with that bal. removed its got to be rotating assy noise like wrist pin maybe, He's done bearings,I hope rod bolts are tight! HUM.....David.

HUNTER39

I changed bearings after rebuild and still have same noise and it's the same rotating assy that was in the block before rebuild but minus the noise, the only difference is the mechanical fuel pump