Oil Pressure Sending Unit, Grounding? Options

[martinef1963]

I took off the pipe that was attached to the top side of my engine case that held the oil pressure sending unit (see picture). In addition, the pipe had the round VDO oil pressure sending unit sitting on top, that was not connected.

The engine tin hole around / above the engine case was big enough for me to tighten the oil pressure sending unit down with 25 or 26MM socket.

My question, does the unit ground itself to engine case? Also, I don't understand why there were two oil pressure sending units on the car - if someone could shed some light.

thanks,

Fern

[type47]

Could be someone used a single pole sending unit for an oil pressure gauge

and the stock sending unit for the idiot light. You can use a double pole sending unit

that will allow you to use a gauge and the idiot light. Oil pressure sensor grounds through the threads in the case (so teflon tape on the threads is frowned upon see reply's below for better info on teflon tape).

[stugray]

The reason for both is:
VDO sender for actual analog pressure
Stock pressure switch for light.

The dual pole VDO has a switch that turns on a little too high of pressure for our cars.
So people use the stock switch.

Stu

[pcar916]

Excellent information above. On one point though I have a different experience. Teflon is just fine for my (tapered-thread) electrical installations for many years.

It's a filler between thread surfaces because it rips away during shear, allowing plenty of electrical contact as it bunches up in the non-contact volume. In fact, I'd depend on that contact not oxidizing a lot better than any crimp-connector. No problem.

To be sure it sounds counter-intuitive since teflon's an insulator, but in fact it works perfectly. (IMG:style_emoticons/default/beerchug.gif)

[r_towle]

There is a rubber seal that you may be missing, but it should be in place...
I believe you may need to go to a dealer to get that part.

914rubber does not list it.
pelican parts does not list it.

rich

[914Sixer]

West Coast Metric shows in under VW BUS. 021-957 $6

[stugray]

To be sure it sounds counter-intuitive since teflon's an insulator, but in fact it works perfectly.

(IMG:style_emoticons/default/agree.gif)

I have always wanted to call BS on the "no thread sealer".
There is plenty of metal on metal contact in those threads, espescially when you thread a 1/8 NPT into a 10mm hole (IMG:style_emoticons/default/stirthepot.gif)

[Cap'n Krusty]

Excellent information above. On one point though I have a different experience. Teflon is just fine for my (tapered-thread) electrical installations for many years.

It's a filler between thread surfaces because it rips away during shear, allowing plenty of electrical contact as it bunches up in the non-contact volume. In fact, I'd depend on that contact not oxidizing a lot better than any crimp-connector. No problem.

To be sure it sounds counter-intuitive since teflon's an insulator, but in fact it works perfectly. (IMG:style_emoticons/default/beerchug.gif)

Teflon tape? Never! I've seen where it goes and what it does when used on the oil system of an engine. Ever seen it in the oil holes of main bearings and cam bearings? I have. Teflon paste, used sparingly, works just fine, but you shouldn't need it with the tapered (pipe) threads of oil pressure senders. The most common leaks from around the oil senders are within the senders themselves, NOT the threads.

The Cap'n