Q: oil pressure on 80 what can be the problem?

The best scenario is if the oil pressure sending unit is simply bad. The sending unit can be tested and/or you can simply tee in a known good gauge to rule the sending unit in or out as the cause. It is technically possible for the the oil pressure release valve to get stuck in the closed position but the only remedy for that is to remove and clean the valve. If that valve is stuck, the effect (on oil pressure) cannot be distinguished from a possibly blocked oil passage which is the final cause of high pressure. Obviously, if a passage were blocked, the engine would be starved of the engine oil it needs for lubrication. Typically if a passage is blocked, you will hear valve train noise (lifter tap) and you may see an oil leak due to high pressure at, for example, the cam assembly. Fortunately, a common cause of high pressure is simply a defective sending unit. If you request an oil pressure diagnostic, the responding certified mechanic will identify the root cause of the problem for you and estimate the repair cost.