nowimnumberone replied:

most oil pressure gauges arnt real accurate.
if your worried buy a good quality gauge and fit it to your dash
cheers

fisho64 replied:

ditto the previous reply, but you can also get a mechanic just to hook a test gauge up to check it.
Supercheap/Repco has the accessory gauges for maybe 30 bucks, get a mechanical one and fit it yourself in an hour or 2

Member - Phil G (SA) replied:

Thats very common - the sender unit is usually the cause.

666toy replied:

have pressure checked with a quality mechanical gauge . if it is still reading low you might have to increase the oil viscosity eg. go from 15/40 to 20/50. your oil pump could be faulty, your big end & mains bearings may be worn. Very hard to say without getting a proper reading of a accurate mechanical gauge first. Increasing viscosity will usually keep it going a while longer.
Toyota oil pressure gauges in that era are notoriously inaccurate however get it checked properly first & go from there ......666toy

Member - Tour Boy replied:

Hi, what the others said about crap guages is pretty close to the mark.
How many km has the motor done. After 250km the pressure relief valves can have deposits form on them if not religiously serviced at 5k intervals. This can cause the valves to either let too much pressure into the system blowing off the oil filter and less commonly low pressure. The lower pressure happened to me, cleaned the valves and good as gold no more probs.
Tour Boy

Member - Davoe (Nullagine) replied:

dont worry bout it - if you really do have low oil pressure the edic motor will shut the engine off. This was a safety feature to prevent the motor running in reverse
................. Unless of course you have a hzj 75 which has no such feature