Sorry if this is sounds redundant. I checked a few other posts to see if have a similar problem, and although I did, the circumstances are different, anyway let me explain.
1990 4x4 22re over 100,000 miles. Engine ran fine before I changed the timing chain guides, only pinging was the chain rattling against the head. Buttoned her back up. Truck ran strong for another 500 miles or so, then while the truck was on the fwy, it was an effort to hold 65 mph, and finally over-heated. Towed it back to the house.
One of the hoses near the firewall had a broken rusted bracket which was leaking anti-freeze, changed that. Gave the engine a once over...the #4 spark plug wire came unfastened at the tip. Also, doubting my work, I checked the torque on the header bolts, each one was about 10 lbs. over torqued. I backed off the torque bolts in the proper order very slowly to the correct lbs. Also fixed the #4 plug wire. Fired her up, now there is a loud pinging coming from the #4 piston area in the valve cover. I thought it was a valve. I checked the clearances, fine, still have a loud ping.
It's not a bang, or a knock, a very loud ping that is not intermittent. Maybe a valve is warped? I thought of pulling the header again to check it out, however before I take on that task again what ideas would any of you have? Thanks very much in advance.