Oil pressure

[PeterTarga]

Hi,

Can someone explain how you must interpret the oil pressure readings for a 911SC of 78 i have a scale to five, what pressure at idle and what when you drive the car. I don't have an owners manual are these still available for my car (language Dutch, French, English, German) ?

Thanks,

Peter

[masraum]

Yes, you can still get owners manuals.

THe pressures can vary by car, but when the engine is completely warmed up the usual pressure at idle will be around 1, and then it will usually be about 1 bar per 1000 rpm until it gets to about 4.5 bar.

So, the usual is about 1 bar at idle, 2 at 2000, 3 at 3000, 4 at 4000, and then it will max at about 4.5 bar which is about 65-70 psi.

It can be less than 1 bar at idle, or it may be more depending upon how warm the engine and oil is and the condition of the motor. As long as the oil pressure goes up when you rev the motor. When the engine and oil is cold it will be 2 to 3 times higher than when it's warm.

[Drdogface]

Be aware that sending units on these gauges can go out and cause the gauge to show low pressure. Before you panic and assume you are in for a major rebuild, replace the sending unit.

[PeterTarga]

Hi,

Thanks already for the response, i drove my car today (cold day but clear sky) and i noticed that when the car is hot and idle 1000rpm i read 1 bar on the gauge but at 2000rpm i have already more then 3 and 4000rpm is already greater than the 5 bar, what is faulty on my car could this be te sender unit or what else ?

Peter

[Drdogface]

It might be going out but might be OK. Mine usually goes up one bar per 1000 rpm. Perhaps other more experienced owners will chime in. Anytime that gauge...or any others...acts up it's best to check the sender frist.

When my sender went out several months ago I could not get over 2.5 bars no matter what rpm. I was thinking oil pump and major tear down but the sender was the problem.

[3.2 CAB]

Generally, when the senders go out they tend to read high, or even peg out when the engine is running. Pressure indications are somewhat abstract between different cars, but it should raise and lower on the guage depending on engine speed regardless