Porsche Repair: 1974 Porsche 911 oil problem, oil pressure gauge, oil pressure switch

Question
I was wondering if you can tell me how to check the oil pressure on a 1974 Porsche 911? Where is the oil pressure switch located?

Answer
Hi Nelson.

You're right to consider the location of the oil pressure switch as the best way to check your pressure.  And I'll describe, as best I can, where the switch is.  However, depending on the engine's shrouding, you may not see it until you dig pretty deep.

Here goes.  As you're looking at the engine from behind the car the area you're going to be focusing on is the top surface of the aluminum case (so pretend the tin shrouding is absent.  On the top right surface of the case, not the cylinderheads, at the forwardmost point, very close to the flywheel, mounted above the oil cooler, is the oile pressure switch...with it's sending wire.

To check the pressure, the best idea is to remove the switch and add some brass plumbing to accomodate a new (and permanent) oil pressure gauge.  Run the tees, elbows, and tubing from the hole you just exposed in the top of the case.  Conceivably you could run tiny tubing up to the dashboard as many cars of that era did...or you could just mount the gauge conveniently in the engine compartment, for your private viewing, whenever you want to take a pressure reading.  Once the pressure gauge is installed, add more plumbing to reinstall the pressure switch in that same line...but not mounted back in the engine case.

Have fun with it.

Dave