Hey, guys! Remember me? I wrote about heavy ticking on my '88 Bronco II after warm up to operating temperature and sometimes after cold start. I measured the oil pressure - it was very low even on 20W50 oil. So I machined the cranckshaft, installed +.25 main bearings and +.50 rod bearings. I also fixed the oil pump by removing wear traces from the bottom cover and took off the pump case about .10 mm of metal to cure endplay of the rotor. Now the pressure is OK, no ticking.
Now for the most interesting part. I was pretty sure that the tapping noise was produced by hydraulic valve lifters due to low oil pressure. But now I'd rather think that it was rod bearing noise. I found out that my cranckshaft was already machined by previous owner. Rod journals were machined to .25 (main were not tooled), but some pervert-embiciles installed .00 (standard) bearings. This, along with a significant wear, produced an enormous clearance in rod bearings, that I could virtualy feel fith my hand with rod big end caps bolted on.
Anyway if you think that your lifters make a tapping "diesel" noise the first thing to do is to measure the oil pressure.
And one more thing - DO NOT rely on engine flush, oil conditioners and other miracles. And I would also not recommend cleaning the oil pick up with a barrel brush ))

Russian Comrade D

 

Thanks for the information and glad to hear you got yours fixed.

 

dont worry if you ever hear the noise after a cold start for about 2 seconds right in the manual it sez that sound is normal and doesnt effect engine proformancei got worried until i saw that one day reading it over

 

yes, sir! i agree on that, slight ans short tapping at cold start is ok. but tapping at operating temp. is a very bad signal