Mine runs about 90 above 4000 when warm. Drops to maybe 30 at 1000. Hard to figure with 85 as the only mid scale marking. There was no change after rebuild a couple of years ago. The pressure regulator works fine. Oil is Castrol 20/50. John
I have had three Dinos, and I could never get any of them to register mid-scale (85 psi) on a cold morning during startup. They all ran rather low oil pressure. I understood this to represent a manufacturing mis-match between the sending unit and the gauge. I have heard mention of the use of the Daytona sender in the Dino, which led to false-low readings. I cannot speak to the validity of this rumor. John C., if I recall correctly, had addressed a voltage divider fix for the false low readings. He added a resistor in the circuit to compensate for this. John, is this correct? The workshop manual speaks to a specification at 7,000 RPM of ? 80 psi ? at normal operating temperatures. I do not have the manual in front of me. Perhaps others could confirm this. My experience in the three cars is that at normal operating temperature, idle oil pressure is barely above the peg. However, the idiot light is not illuminated, giving comfort (perhaps false) that the pressure is greater than indicated on the gauge. Of course, these low readings are despite proper adjustment of the oil pressure-limiting spring at the base of the oil filter unit and after complete engine rebuild. Jim S.
From my manual (page 42): "When the temperature is between 230-250 F (110-120 C) and the engine revs are approximately 8000 (!), the normal oil pressure is 85 lbs sq. in. (6 kg cm sq.). If under similar conditions the oil pressure is below 75 lbs. sq. in. (5.5 kg cm sq.) the engine revs should be reduced and the reason found for the pressure." It would have been helpful for them to specify a pressure value at an engine speed that isn't 200 rpm above the redline...
But that would be what Toyota would do! Got to admit, you can't read that and not smile! 200 above red-line...
I screwed a mechanical oil pressure gauge into the spot where the sender unit is, made notes of what it read at what RPMs, then did the same with the sender unit in (or reverse order, I don't recall.) The error was not consistent, but seemed to be about 25psi. So my gauge in the car has a sticker saying "25 LO", giving me a rough idea of what it really is. Since the sender and gauge will change with time, I'm not sure there's too much point in trying to make the electronic gauge super accurate.
Jim and all, The Saga about the Oil Pressure was a couple of years ago. Went back and looked: http://ferrarichat.com/forum/showthread.php?t=119757&highlight=060903___Oil Got to the chart at the end of the text and said Damn. 42 and 85 psi ohm values are missing a leading 1. 42 psi @ 180 ohms to ground. 85 psi at 100 ohms to ground. I posted a correction at the end of the thread. This test was to find the sensor value required to make the meter read a certain value. I still have the Nissan sender in the car and the in line resistor is there to make the pressure accurate at 85 psi. It is also close at 0. Below 85 it reads high then low, above 85 it reads low. Since 85+ was the standard reading before sensor failure, I just matched the reading. I assume the Ferrari part makes the gauge read properly with no correction. Be nice for someone to measure what stock sensor reads at different pressures. I doubt that there is any problem with the oil system if the regulator starts to kick in around 2,500 rpm and the normal driving needle is within 1/8" of the 85 mark on the gauge. Maybe 3,000 to 7,000 rpm? Maybe 70 to 90 psi? John
