SC Oil Pressure

[RG Najarian]

Hello Gang,

I've got a 1983 SC Cab with 138,000 miles with the usual SC issues, oil leaks and oil burning (maybe 1.5-2 quarts per 1000 miles)

My question is regarding the oil pressure.

At Cold with thicker oil the revved Pressure is 5 or near 5, Idle is around 3.

When Warm the pressure is 3-4 revved and the idle pressure is 0-1.

Occasionally the needle will jump erratically. For instance at a constant rpm the oil pressure will be at 4 then jump spaztically to 5 then 4 to 5 then settle down at 4 again.

Some posts I've read says this is status quo for these vehicles. What are your thoughts about that? AND what is a good way to manually/externally check the oil pressure?

Thanks

[judgejon]

Hello Gang,

I've got a 1983 SC Cab with 138,000 miles with the usual SC issues, oil leaks and oil burning (maybe 1.5-2 quarts per 1000 miles)

My question is regarding the oil pressure.

At Cold with thicker oil the revved Pressure is 5 or near 5, Idle is around 3.

When Warm the pressure is 3-4 revved and the idle pressure is 0-1.

Occasionally the needle will jump erratically. For instance at a constant rpm the oil pressure will be at 4 then jump spaztically to 5 then 4 to 5 then settle down at 4 again.

Some posts I've read says this is status quo for these vehicles. What are your thoughts about that? AND what is a good way to manually/externally check the oil pressure?

Thanks

I think there is a tool that goes on the oil filler for testing oil pressure, but not sure.

Does the problem happen when the engine is hot and you're going around a corner? If so, there is a traditional problems with older oil pumps that do not have a screen-like part on the pick up tube. on hot runs the intake on the older style pumps can be above the oil level in the sump. If that happens the car with either just stop or the oil pressure gauge will jump around.

If your just idling, hot or cold, I'd bet the problem is in the pump itself. shouldn't be as they are really realiable as far as I know. I replaced mine "just because" we were into the engine box anyway. It's been sitting on a bookshelf in my office for years, and very very few people have any idea that it's a Porsche engine heart.

Problem is that if your problem is the pump, you gotta take the engine apart completely to get to it, even taking the case apart, as far as I know. Loren would be the expert on this one I bet.... good luck.

[judgejon]

Hello Gang,

I've got a 1983 SC Cab with 138,000 miles with the usual SC issues, oil leaks and oil burning (maybe 1.5-2 quarts per 1000 miles)

My question is regarding the oil pressure.

At Cold with thicker oil the revved Pressure is 5 or near 5, Idle is around 3.

When Warm the pressure is 3-4 revved and the idle pressure is 0-1.

Occasionally the needle will jump erratically. For instance at a constant rpm the oil pressure will be at 4 then jump spaztically to 5 then 4 to 5 then settle down at 4 again.

Some posts I've read says this is status quo for these vehicles. What are your thoughts about that? AND what is a good way to manually/externally check the oil pressure?

Thanks

ps: what oil are you using? maybe you need to use a different viscosity...?

[wvicary]

The oil pressure sender is starting to fail. That's what is causing the erratic readings at a steady RPM.

[RG Najarian]

I'm Using Pennzoil 10/40.

The pressures indicated are for straight line (no cornering).

Admittedly I usually keep the oil level on the slightly lower end of the dip stick. I've added a quarter quart and the numbers have improved.

I've already bought the sender. Hopefully I'll be swapping it out soon.

Thanks for the input

Edited June 6, 2008 by RG Najarian

[judgejon]

I'm Using Pennzoil 10/40.

The pressures indicated are for straight line (no cornering).

Admittedly I usually keep the oil level on the slightly lower end of the dip stick. I've added a quarter quart and the numbers have improved.

I've already bought the sender. Hopefully I'll be swapping it out soon.

Thanks for the input

yes. good thought re sender replacement. hopefully a relative cheap fix, and sounds like that could really be the problem. the key was the straight line rpm. I'd go to 20-50 for the SC. good luck. let us know if the sender swap is the solution.

[Stephan Wilkinson]

The rule of thumb is that you should have one bar of oil pressure per 1,000 rpm when the oil is warm. i.e. "revved" means little to me, but if you get four bars at 4,000 rpm, that's normal.

[SkipC]

My '84 911 oil pressure gauge needle jumped around a lot or was rock steady. Turned out to be the wire going to the sender. It looked fine, but, on close inspection, there was only one wire strand connected between the wire and the connector. The rest had corroded inder the insulation. Re-solder foxed it right up. Note: there is almost no extra wire, so if you have to do this, be sure to remove the absolute minum amount of wire.

Good Luck, Skip