94 f150 knocks when cold then goes away at operating temperature.

[Redtruck]

I have a 94 f150 with a 302 that has 245,000 miles and has been making a knocking sound only when cold. When the truck is warm the sound disappears. The sound seems to be coming from the bell housing. It is not loose flexplate nuts or a cracked flexplate already checked and replaced. It has been making this noise for about 40,000 miles and hasnt seemed to have gotten any worse. I checked for rod knock by grounding each individual cylinder and knock is still there. Truck runs perfectly fine uses about a quart of oil every 1200-1500 miles no leaks been using 10w 40 valvoline maxlife since about 200,000 miles for the oil consumption which hasnt seemed to increased much since.

[Redtruck]

Does anyone have an idea what might be wrong?

[Meat-Head]

Yeah 245,000 miles, due a hair cut or knackers yard, wait untill something falls off, then see if it cured it.

the fact it happened fir such a long time makes one think don't worry, but see one night on heavy-r.com oil seal plugs in the head. Has two oil pumps or SONETHING.

is the oil clean?

[Redtruck]

Yes oil is always very clean.

[ontherack]

big end/crank bearing worn

[Redtruck]

Don't bad crank bearings get louder when the engine warms up?