Loud clicking noise coming from top passenger side topside. In sync with rpm's. A quick search led me to try an oil change after running seafoam through the crankcase, no change. In fact truck actually cut of saturday twice for the first time ever. Any other suggestions? in the meantime, can someone tell me exactly what is involved with changing the timing chain on one of these? 98 SOHC.

 

Probably the cam phaser and not the timing chain.

 

Not in '98.

 

If in sync with rpms, maybe a stuck valve or lifter issue. Not sure why it would stall unless it won't run with one cylinder acting up but not likely. Haven't heard of many time chain issues with these motors.
Maybe a grounding cop if one of the boots are cracked. You did say "clicking."

 

I'm going to upload a video this evening.

 

Had the same clicking noise on passenger side front of engine with the same missing(never died though). Had a cracked boot on the # 1 COP. Changed it last weekend. It's the easiest one to change and worth a try for the $42.00 it will cost you and the 15 mins. of time. Would be alot cheaper and easier than doing a timing chain.
Just a point to ponder.

Bernie