I just changed my timing belts, 91 Accord, after 220K. Noticed pressure light would flash after 20 minutes of driving. Removed sending switch to check pressure- After 5 minutes of reving at 3krpm pressure would drop from 75psi to under 10psi @ (3krpm). Oil would then begin to leak at bottom of timing cover, just below crank shaft. Oil was not hot, but cold, as if it never reached the internal parts. Changed oil and filter, but still same results. Can any one diagnose this problem. I will hate to buy a new motor.

 

sound like an oil seal on the oil pump

 

You need to pull the timing cover. Possible source of leak(s) cam seal, balancer shaft seal,crank seal, oil pump seal. If your oil pressure is low, you risk major damage to the engine. Fix it now, I would not recommend driving it until the problem is resolved.