1992 f150 5.0 started knocking only when its cold its coming from the front of the engine truck holds 62 psi (oil pressuee) at idle when cold and 25 when oil is hot. The motor has 40,××× miles on it. If yall need Any more infojust ask. Thanks

 

Could be a bad wrist pin

 

It goes away when the oil gets warm its more of a thumping sound and goes away when throttle is applied. My guess is its a main end bearing? From what I've heard old ford techs say they go bad quicker because of the firing order(front two firing right after each other) its also at the bottom end. I forgot to mention

 

Check for a crack in your exhaust manifold. Open when cold, causing the noise and closed when hot.

 

Manifolds aren't cracked that was the first thing I checked its definitely coming from the front bottom of the motor its a thump not a knock

 

Truck sat all day yesterday started it up today no knock. Could this possibly be spark knock?

 

I'm running 5W-30 from the winter.I'm gonna try to switch to a heavier weight

 

UPDATE truck does not knocl when its cold anymore only when it gets hot and cools down for an hour or so. Maybe thinkg its spark knock?? Any help??

 

UPDATE. found the problem a cork in the vent hole on the driver side valve cover. When I opened it sounded like an air compressor releasing its pressure. I guess it was causing excessive crank case pressure