oil pressure sender/gauge question

Enrique · 02-25-2002, 10:12 AM

I've got a question about my oil pressure gauge. I've got a '68 911 (w/ the '68 911 gauges) with a '67 912 motor powering it . I installed a 912 tach, no problem. The oil temp part of the gauge functions, as does the oil pressure idiot light. But the *oil pressure level* part of the gauge doesn't want to work with my oil pressure sender. The wire that is currently controlling the oil pressure idiot light is connected to my oil pressure sender. As an experiment I connected this wire to the oil pressure level plug-in, but the needle just shoots to the top.

How can I get the oil pressure level on my dash? Is there a 912 oil pressure sender that will bolt to the motor and operate the 911 gauge? Does any of this make sense? Anyone have a solution to tell me or sell me?

Thanks as always.

WFBowen · WFBowen's Garage

Enrique:
I may be misunderstanding the situation, but here's my take: The 911 (as I recall - it's been a while) has three senders; Oil Pressure; Oil Temperature and Oil Level. The oil level sender takes its reading from the resovoir (oil tank) since its a dry-sump system. The sender for the oil pressure on the 912 is basically an on-off arrangement which kills the green light at about 5-7 psi or so. To get the incremental gauge to work, you'll need a different sender. If possible, check to see if the 911 sender has the same thread size or can be mounted with an adapter. Also, VDO makes these for their aftermarket conversion gauges and they fit the 912, however I think they come in two flavors - 0-80lbs & 0-100 +/-, so accurate calibration becomes a problem, but with oil pressure its usually a case of having it or having none, so dead-on gauge readings are not as critical as the fact that the gauge is indicating good pressure or not - make sense? Also, if you're missing the oil level function on the 912, it was always a so-so thing (years ago I had a Jag XK120 with oil level reading and it was really a crowd pleaser to push the button and read my oil level. In reality, it had nothing to do with how much oil was actually in the sump.) Best gauge is still a couple of dirty hands on a clean dipstick!
Good luck.
Bill.

Enrique · 02-26-2002, 03:20 PM

Bill- right on. I need two terminals coming from my sender- idiot light and pressure. I do have a couple of local leads on 911 senders, but I'll have to confirm the threads are the same, and that it'll fit in that little nook behind the dizzy.

Failing that, I found out I can get a $50-$60 sender from Palo Alto Speedo, and they'll calibrate it to the gauge itself. I would send them my gauge for that purpose- (not that I care too much about that, I dig what you're saying about relativity of the pressure).

Anyway, thanx!

Morrie · 02-27-2002, 03:05 PM

The sender on my 67 is shot- light never comes on until I short the terminal to ground.

I'm sure that Porsche wants a small fortune for the sender- is there a reason why I can't go down to my local auto parts store and buy one of those inexpensive guages with the oil tube and universal fittings? I was thinking I could make a small bracket and mount it in place of my clock.....

Definately not stock, but waddaya think????

Best,
Morrie

WFBowen · WFBowen's Garage

Morrie:
I'd suggest pulling your sender out and running on down to a VW/Dune buggy shop & see if the threads are the same - if they are & it looks like it'll go in, then you're in business. The stock unit for 912's is the same as 356, so VW just might work. As for the pressure gauge, I'd suggest a cheap electric sender/gauge combo. It's a long way back to the engine on a Porsche and there are too many places that could mess up the plastic line on a mechanical setup.
Good luck,
Bill.

mein12 · mein12's Garage

Hi there,

I use a 69 911 gauge in my 912. I used the sender that was on the same 911 and it theaded right into the gauge block. The pitch is the same but one is tapered. It has worked fine for ten years.
Here's some pics.

Enrique · 02-28-2002, 06:39 AM

Mein912:
Does the 911sender send a signal to BOTH the idiot light AND that oil pressure needle on the right side of your guage face? If so, my problems are totally solved w/ purchase of a functional 911 sender. The 911 sender then has two terminals, and/or two wires coming out of it?

Morrie:
I agree w/ Bill- find a proper replacement for your sender. Last year I replaced the sender on my 914 w/ a VDO unit purchased from a local VW performance shop for less than $20.

Best,
Enrique

mein12 · mein12's Garage

Hi, there is only one wire and it is the signal for oil pressure. There are two idiot lights on a 911 gauge. The small lite at the top is for the emergency brake/ brake failure. The one at the bottom is for generator/ alt.
I hope this helps, JMB

Green 912 · 02-28-2002, 10:51 AM

The one I use. One term is for the oil light and one is for the oil pressure guage. The temp sender can be seen in the backround and yes, the oil line is in a loop. I use a full flow external filter/cooler. The much restricted loop line allows a small amount of oil to flow through the oil block thus giving more acurate temp readings but not bypassing oil.