Hi, there are a few things that you can try, to eliminate the noise,one is to put a pint of automatic transmission fluid in the engine oil, this will many times clean up a sticking lifter. Next would be to try a different oil, a conventional 10w 30, it is a little thicker and may quite things down. Lasly I would try adjusting the valves, below is the procedure for doing so on your Bronco 2.9 engine
Thanks for the tip.
Should I run the ATF until the next change or should I just run it for a while and then drain and replace the oil? If the detergents really work it would probably be a good idea to at least change the filter once it has got the gunk into suspension and over to the filter. That would drop the oil level about a pint as it would be a pint hight if I add a pint of ATF.
This car is something of a hobby for me. I enjoy keeping it running as long and as well as I can. Cosmetically it is in good shape and I just treated it to 5 new Michelin tires.