a knock.........?
 

having a slight inconsistent knock from a 350.
dose not have the typical rod knock noise.
i was thinking it could be the crank hitting the oil, flex plat bolt lose or it could just be a plain old rod knock.

dose not do it when it is at operating temp.
only after it cools.dose not do it under exceleration.

any ideas on what it could be before i tear into it.

thanks a lot

jared

Re: a knock.........?
 

Is it a loud knock? Small or large knock?

Re: a knock.........?
 

very small knock

Re: a knock.........?
 

Lifters bleeding down while cold?

Re: a knock.........?
 

Rod knocks get louder when warm when accelerating the motor. Main bearings knock at idle but shut up (generally) if accelerated. Piston slap is usually louder and more like a clatter. If you can shut up the noise by shorting out one plug wire, it's probably that rod or piston. Bad bearings usually make a lot of noise when started cold but get quieter. Flex plate loose should shut up when placed in gear. Maybe it's just something wanting to get in, or get out. Lousy joke. Knock knock. I once swore that a hopped up '55 Chev that a friend of mine had built had a horrible rod knock, and so did the owner. The machinist just laughed and said bring it back. It was an exhaust pipe hitting the frame at idle.

Re: a knock.........?
 

Check the fuel pump, if it is about go, the fuel rod tends to create a knock down low in the engine and it sounds a lot like a rod knock.

Re: a knock.........?
 

Take a look at the flexplate also. I have seen then crack between the bolt holes that hold it to the crank. Makes a loud knocking noise, but temperature generally doesn't affect it, IIRC.

Re: a knock.........?
 

ok cool.
thanks guy for your awesome inpuy

Re: a knock.........?
 

would the little spacer cause a small knock between the flex and the crank or it just look like a spacer.

Re: a knock.........?
 

make sure the torque converter bolts are tight. a main knock is a deeper knock. you will usually feel it in your feet and it will go away with rpm and higher oil pressure. is it louder in gear?

Re: a knock.........?
 

I don't think there is supposed to be a spacer. You might be looking at the crank flange. If you have the inspection cover off, start the engine. You will notice right away if it is coming from there. The noise will be pretty apparent.