oil pressure (high)????

tops911 · 04-14-2011, 12:17 PM

Hi I have a new to me '82 930 and have a question about the oil pressure.
The gauge is in PSI and at about 2600 RPMs the pressure is around 100 PSI. At idle the pressure is around 50 PSI. This is at about 190 degree oil temp, this all seems high to me. Now the cam line oil restrectors have been changed to the "improved" reduced flow ones. I plan on changing them out, or just drilling them out. But I wonder if I might have a bad sending unit. Is their a difference between a sending unit that reads BAR vs on that reads PSI? I almost wonder if it might be the sending unit because the temp sending unit was the wrong one, resulting in the temp never reading on the gauge.
What does the brain trust here on Pelican think? thanks

spuggy · 04-14-2011, 01:22 PM

I don't think the PSI gauge is stock for an 82, didn't SC and later use a 5 bar gauge?

Sounds like that is from an earlier car (my '77 has a 0-140 PSI gauge).

PET gives oil pressure sender part # as 911 606 111 00 for 1974-1983 (930's and 911's), and 911 606 135 00 for 1984-1989. Our host agrees, with minor revisions of the last two issue numbers, and some stock code for Porsche vs. VDO source.

So my guess would be that the internals of 78-83 5 bar gauges would be different to the 84-89 5 bar gauges.. Whee...

tops911 · 04-15-2011, 06:19 AM

I'll try to read the number on the sending unit. I'm thinking I may have the wrong sending unit.
Thanks

spuggy · 04-15-2011, 09:59 AM

Quote:

Originally Posted by tops911

Thanks

You're welcome. I notice that you stated your oil temp was 190 degrees - just FYI, note that the numbered gauges do show the oil pressure as much higher - like 120 PSI - on a cold start.

Which allows you to see the engine thermostat opening/closing (pressure bounces down 10 PSI or so for a fraction of a second). I generally fast idle for 90 seconds or so until I see it bounce 2-3 times in quick succession and then select a gear. With a 5 bar gauge, it would just peg when it's cold...

tops911 · 04-15-2011, 11:34 AM

After checking the sending unit it's pretty clear I have the wrong one, the number on the sending unit is 911 606 111 01 which seems to be for '78-83 cars. I'll be ordering the correct one soon (I'm in the middle of a move to Germany). It's pretty amazing that both oil sending units were wrong for all these years.
Thanks

smurfbus · 09:49 PM

Where is the number on the sending unit? Mine (79 930) only has "VDO, made in Germany" printed on top of it and it's the only visible print but it doesn't show on the pic below.

I have 90 PSI (VDO PSI gauge) cold idle and it drops to 60PSI when warm. Cruise is about 80PSI

tops911 · 04-25-2011, 04:40 AM

Smurfbus,
my sending unit is different than your; it does not have the black plastic or rubber across the top. However the part number was right across the middle on the top of the sending unit.
I hope this helps

spuggy · 04-25-2011, 09:24 AM

Quote:

Originally Posted by tops911

After checking the sending unit it's pretty clear I have the wrong one, the number on the sending unit is 911 606 111 01 which seems to be for '78-83 cars.

According to the way I read PET, that's the part # for 1974-1983.

The sender has to match the gauge in use; if you have an early (74-77) numbered gauge, then that sender would be matched. If you have a later (e.g. 5 bar) gauge with a numbered insert stuck over it, then you should figure out what it's reading.

Try removing the gauge and looking at the date code on the back.

tops911 · 04-25-2011, 04:51 PM

My gauge goes from 0-150 lbs, so I was told I need a sending unit for a 74-77. I got the part number info from the Pelican catalog. My car is on it's way to Germany and I wont see it for a month or so. I'll have to wait until then to do more fixing on it.