997 oil pressure

[Charlynsane]

Hello Guys

I have a problem on my old 997 survivor





The oil pressure falls when the car is hot

The engine has covered about 85 000km, but drive great, smooth gearbox, full of torque, no weird smoke anything

The oil pressure when cold is 70 at idle and 80 when I'm driving

When engine is hot 10 at idle and 55/60 when I drive the car

I already changed the relief valve and it's spring

So now.. how can I know if it's a problem with oil pump or bearings?

Than

[LarryLebel]

I'd say its OK at speed but seems low at idle. What's the idle rpm?

[Charlynsane]

My iddle rpm is 900 rpm

But i just fitted a kad adjustable pressure relief valve

[Herbert]

I can only say that if it was my motor, Ir rip it out and check the mains/big ends. If they are not 100%, I would then also check the cam liners. It would be a travesty to run the crank in.

[Spider]

Given it's milage, that's not too bad but is showing signs of getting tired.

I'd suggest not worrying too much about it for now as it still has some life in it, but will shortly need and overhaul. I'm sure you'll find the Pump will be scored and worn and the Crank will also have some wear.

[Daveislandblue66]

How old is the oil? It's surprising what a change of oil and filter will do. Mineral-based oils seem to deteriorate, regardless of mileage. Modern synthetics don't suffer from this, but no good for a Mini.

[Hipwell]

Given it's milage, that's not too bad but is showing signs of getting tired.

I'd suggest not worrying too much about it for now as it still has some life in it, but will shortly need and overhaul. I'm sure you'll find the Pump will be scored and worn and the Crank will also have some wear.

Exactly this, the low idle oil pressure isn’t going to hurt anything. Drive it until it needs rebuilding.

Your using a 20w/50 oil?

[abri]

The BMC workshop manual says 10 psi per 1000 rpm. While yours is getting close to the lower limit, it’s still in spec.

[Charlynsane]

Hello Guys

Yes The oil is new and I use 20W50 millers oil

I tried with the KAD system tightened and the pressure isn't better

at idle



at rev (4000 rpm)


And there is a leak other there, maybe the gauge metal hose or maybe the oil pressure hose from the oil filter to block

I'm gonna check carefully, it may be why the oil pressure became so low suddenly?

I will try to change only the pump because the engine drive great and to avoid a total overhaul of the engine

[Polarsilver]

Can you try a capillary type Oil Pressure Gauge to establish the actual Oil Pressure reading..?

[bwaminispeed]

These gauges are direct reading already, they don't use a sending unit like the temp gauge.........

I'd be happy with that oil pressure......

[mk1]

As above.

I don't really think that you have anything to worry about.

It's a 80,000k car that still has respectable oil pressure. OK, if it was a new build I'd not be too thrilled, but after that many miles I'd call it perfectly OK.

Remember the old factory OP warning light was rated at 7lbs.

[Charlynsane]

Many thanks guys

I will pull engine out to check the oil pump during winter

The oil pressure started to decrease a few months ago

Before that the engine oil pressure was 20 at idle and 75 at 4500 rpm

But as said above, it's a 57 years engine never opened, never rebuilt

Thank you for all your helpful explanations