Druck Pressure

[ldortiz]

I have an 86 Carrera. I Added a quart of oil since the car was down a quart and I then noticed that the druck pressure is a little high. When I first start the car cold the dp needle goes up as high as it can then when the car is warm it drops to between 3. 5 and 4 when I am running between 2800-3000 rpms. The car runs fantastic but I'm wondering if this is a problem.

Thanks,

Leo

[Flieger]

I don't mean this in a bad way, but you must be new to Porsches

There have been countless threads on "druck pressure"

1. Druck is German for pressure. "Druck Press" on the gauge allowed them to use a standard gauge between english and German speaking countries.

The proper term is "Oil Pressure" or "Oel Druck" auf Deutsch.

Now that you are not getting laughed at,

2. High Druck while cold is normal. I run 20W50 Castrol GTX in my RS spec 2.7 liter. I have a front mounted oil cooler to supplement the engine cooler. The thermostat to the front opens at about 180 degrees F.

On start-up, my Oel Druck is 60 psi at idle (~1000 rpm). It revved to 2000 or 2500, the pressure can easily go to 80+ psi. As it warms, the idle goes to about 1500 rpm and the pressure starts to come down. My oil never gets above 185 F even being aggressive on hot days.

When at operating temperature 180 degrees F, Oel Druck is ~15 psi per 1000 rpm. This is the optimal spec for Porsche 911 oil pressure.

It is a more accurate reading to raise the revs to about 2000 when checking pressure, because the numbers are greater. Some cars have no discernable oil pressure on gauges without marks when at warm idle. This is common. As long as the oil pressure at higher revs is 10+ psi when warm.

The high oil pressure when cold is why you must be very gentle until the engine is warm. It can damage rubber seals and delicate oil cooler internals.

Happy Motoring.

[ldortiz]

Thanks, well I have always loved Porsches but am quite ignorant about the mechanics. I knew druck presure was a redundant term and I too run 20/50 Castrol GTX. I think I am a bit too cautious when I think something with the car may not be right.

Cheers,

Leo

[Flieger]

Its hard to tell who knows about Druck=Pressure and is joking and who is clueless. Sorry.

I think a lot of things on Porsches are seen as scary from the mystique of exotic cars. If you stay out of the engine, there is a lot that is pretty simple and not easily damaged/fixable. They just cost more.

Wrench away, that's part of the fun

[tcar]

... and, the pressure is in BAR, not PSI. (BAR = Barometric pressure)

1 BAR = about 15 psi., 2 BAR = 30 psi...

[Flieger]

Yeah, on the later 911s I know it is BAR.

Mine is psi, though. I like the better resolution and response.

I have a 1971 911S.

[ldortiz]

Thanks Flieger,

I plan on attempting some of the easier projects to begin with. Life is a marathon not a sprint. Enjoy the ride. Any pictures? I love the early 911s.

Leo

[Flieger]

Since you asked...

It has all fiberglass panels so don't let the IROC fool you, it is a 1971 911S. 2.7 liter MFI RS spec, airport 911 transaxle, roll cage, 2000 pounds with fluids, grippy Advan A048s

[the]

How about some pics of your E21? I'm a big fan of those!

[Flieger]

Sure:




Its a great daily driver. The manual steering is much more communicative with feedback. It is much quicker and sharper than normal front wheel drive Toyotas. The manual gearbox is refreshing in a sea of slushboxes.

[Flieger]

Thanks for the kind words.

[Flieger]

How about some photos of your cars, Idortiz and the?

[Zef]

Flieger...your 911 is superb... Woooooooooo....

[Joeaksa]

Originally Posted by ldortiz

I have an 86 Carrera. I Added a quart of oil since the car was down a quart and I then noticed that the druck pressure is a little high. When I first start the car cold the dp needle goes up as high as it can then when the car is warm it drops to between 3. 5 and 4 when I am running between 2800-3000 rpms. The car runs fantastic but I'm wondering if this is a problem.

Thanks,

Leo

Leo,

Has anyone showed you the correct way to check your oil? With the entire system warm and engine idling?

Just checking as there are plenty of people who have never been shown the correct way and think the system is low and add a quart. They then find out that its been filled too much when it pukes the extra oil out into the intake or airbox.

Just checking and if no one has shown you pls let us know. Also just in case, pls do not trust your engine on the "oil quanity" gauge. Check the oil manually from time to time just to make sure.

Joe A

[ldortiz]

Flieger,

Your 911 is awsome. Do you take it to the track? I owned a 320I identical to yours about 25 years ago when I lived in the Bay Area. I traded my 75 914 in for it. I'll try to load some photos of my car. Mostly stock with a performance chip, 10 disc cd changer and Alpine alarm system.

Cheers,

Leo

[ldortiz]

Thanks Joe for your support. Yes I always check with the engine warm and running. I appreciate your concern. While these cars are bullet proof in some ways we need to treat them gently at least when we are performing maintainence on them. This forum has prooved to be invaluable to me. The expertise of the Pelican gurus is quite impressive.

Thanks,

Leo

[jwetering]

Umm - since no one has come right out and said it, I will.

When at normal operating temperature the rule of thumb is 1 bar for every 1000 rpm.

When cold, the pressure will be much higher because the oil is thicker.

When *hot* the oil pressure may be lower because the oil is thinner.

At idle it's ok to have the oil pressure light flicker once in a while (although this never happened with either of my 911 motors. The oil pressure light switch makes at 0.5 bar.

Simple as that - oil pressure too high is rare - don't obsess, just drive.

[Flieger]

Thanks for the compliments on my car.

I dont track the 911 because that means about a 120 mile highway trek into the desert (Willow Springs) or to Fontana Speedway. Not fun in hot weather with a loud car. I turn about 4000-4500 rpm on freeway and there are no windows, heater, ac, or anything. The tires are DOT-Rs so it is nice to keep the mileage down.

I have autocrossed at the local airport (airport gears) but the track is always set up much too tight to be fun.

With the roads around here, it just is more fun and pleasant to go through the canyons or down PCH. The views are great, there is lots of elevation change, good pavement, and I know roads that see little traffic.

I always keep a sharp eye out for other drivers and keep it safe, though. I don't want to hurt anyone, just have a little fun.

[nut11]

Sweet...

87 blk coupe