My 456 has started to develope high oil pressure readings after a standing for approx 2 months and suffering a flat battery. After changing the battery and warming the engine up the tick over pressure was 3 bar (normal according to the manual). Water temp was 90C, tick over normal revs. Once driving the oil pressure would climb to over 10bar at 3500rpm. The manual says 92psi at 6000rpm (6.5bar). Naturally I backed off and have booked it into the garage for oil and filter change and investigation. Has anyone else ever experienced this. Other than that the engine is faultless, which can't be said about the electronics, seat operation, windows.....
Oil Pressure Senders can be unreliable, if not that I'd suspect the Oil Pressure Relief Valve is stuck
The manual for my 456M GT states that the pressure should be between 5 - 6 bar (72 - 87 psi) at 6000 rpm. Mine reads about 105 psi (7.2 bar) at 6000 rpm (and about 70 psi on tickover). It has always shown this in the 6 months I've had the car. I'll get it checked out soon, but I'm not too worried about it (should I be??)
