My Little Green Light

I'm sure you'll get the right response from the guys here but my 2p worth (I'm British) I would have thought the green light meant oil. And I suppose it's possible that as the oil gets hotter, the pressure goes down, hence the light. But you say your lights aren't too good. Maybe the alternator (wired to the green light ?) is not performing well and gradually starts glowing.

Those are 914 gauges with the optional temp gauge.  If wired per OEM diagram that indicates low when flickering and very low to nada oil pressure when steady on.  In this case green is not good or "GO".  Check oil in engine via dip stick. Did you recently replace engine oil with low viscosity oil? VW T1 engines do have low oil pressure at idle when warm but it kicks up to turn light off at higher (than idle) RPMs.  I'd check connections to sender (stock sender is just below the distributer) and even replace the sender.  If its not dirty loose wires or sender - then the bearings are worn and will need to be replaced (i.e. rebuild engine time).  Hope its oil level or sender - but I would not drive with it on.  (I guess it could be oil pump too). How many miles on engine?

Photo is of a dual sender (for the idiot light and an oil pressure gauge.

If it is wired wrong and it is the generator (alternator) really - Advance Auto or others can check to tell if you battery, generator (alternator) or regulator are going/gone.  The dim lights point to it maybe being wired wrong.

To double check, pull the wire off oil pressure sender (while engine is running) - if the green light goes out then it was wired correctly and you have oil pressure issue.

Wolfgang et al,

letme preface this by saying I'm new to these engine types.  That said, I'm assuming the round silver/grey module with the two wire connectors attracted to the brass elbow fitting is your oil pressure sensor.

I don't have that sensor attached to my brass elbow fitting.  What I have is a single red wire connecting to the brass fitting.  When I disconnect that, the light stays on.  That wire enters a bundle some of which go to the ignition coil.  I also traced a red wire from a fitting at the base of the engine.  When I disconnect that, th light goes out.  seems to be a oil leak somewhere near that, as oil grime was sigmificantly built up there, and wet.

did someone steal my oil pressure sensor module???

That looks to be the oil temperature sender in one (if dual) oil pressure circuit relief valves (if you were to unscrew it it would have a piston and spring behind it) which regulated flow of oil and pressure).  The one by distributor is the pressure sensor.  The 2 sensors should be have separate wires up to the gauges or lights. 

That brass fitting is usually only there to give the dual sender (idiot light and an oil pressure gauge) room to screw in. (It is a generic photo and looks like it has a turbo oil line or a mechanical oil pressure gauge hose to it too). You should have the oil pressure up there. (with a brass T you could put the oil pressure sensor and the oil tem sensor there - but not best place for accurate oil temp readings).  I can't see that it would read proper oil pressure if screwed in where the relief valve was located.  Can you see a part # on the one in photo?  Might determine what sensor it is.  Provide photo one brass fitting near distributor.

In drawing you can see where the sensor goes.  Where the arrow is is where that sensor is mounted on yours.

I have a question:

You indicated up above that the green light is OUT when you first start the engine, but, after five minutes of running (idling, I assume) the light glows faintly and then comes on full a bit later.

If the light is on full at idle, and then you rev the engine to, say, 3,000 RPM or run it normally down the street, does the light go out?

Is the light out when you're driving around, but then comes on when you stop at a light or stop sign?

I ask this because you either have borderline-low oil pressure in your engine, or a bad oil pressure sensor (or both).  That sensor on the bottom of the engine, with the oil all over it and everything else around it, is your oil pressure sensor.  How do I know?  Well, when you removed the wire from it, the green oil light went out because you opened the electrical circuit to the light (the sensor closes a switch to ground (the engine) and lights the light below about 5 pounds oil pressure).

The only way to tell if you truly have low oil pressure is to take the car to a mechanic who has an oil pressure test gauge.  He will connect that to the oil pressure port on the engine (next to the distributor is the usual place, although where yours currently is might be a good second choice) and use that to see what the oil pressure really is.  It should vary between 5-6 pounds at idle to 25-40 pounds at 3,000-4,000 RPM.  

Only by testing it with a gauge will you know if your sender is working correctly or out of whack.

I'm a little interested in where your oil pressure sender is located - that is usually (I think....if I follow your picture correctly ) where the cap for the oil pressure relief valve should be.  Not unheard of to have the pressure sensor there, just don't know if the pressure valve is installed correctly up above it.

Just thought - Oil pressure senders are notorious for leaking oil after a while, so that may be the source of your oil leak, but there may be a lot more going on there than just a leaking sensor.  Have someone competent look at it.  They should spray the entire area with a good degreaser, then hose it off to get everything clean and only THEN can they see what's leaking to correct it.

Wolfgang - here's two photos.  1 with the distributor cap, and the second a closeup of the brass fitting.  The second red wire extending down and out of the engine compartment comes from the sensor at the bottom of the motor.

Gordon - the green lights is off upon engine startup, then begins to glow after a few minutes of idle or running, then I'd on constantly at idle or at speed

Well, it sounds like a bad sensor, but without testing it you'll never know if the pressure is up to snuff or not, so get it tested.  I would also move it up next to the distributor as Wolfgang suggested by using a "T" fitting with both the oil pressure and temp sensor on the same spot and put the oil pressure relief cap back on without a sensor down there.

There is a whole lot of oil all over the place, and it looks like the o-ring on the distributor shaft is leaking (at least - there may be others) so it's time to find a competent VW mechanic and let him/her make it right.