OldPunk
OK, I don't have a whole lot of experience with oil pumps in general, but I've encountered a mystery on our 71 Standard Bug that requires your input to solve. The engine's a single-port, stock 1600 engine with the offset doghouse oil cooler and no oil fiulter. But the oil pump has a secondary set of gears outboard, or to the back of, the initial, normal set of gears. The two sets a separted by a plate and a rubber seal for the shaft of the driven gear. The gear which is NOT driven in the primary set has a long shaft which sticks through the plate, through the rubber seal, and drives the secondary set of gears. The seondary gears have pipe fittings on the housing for in and out. However, because of the separation by the plate and seal, engine oil does not circulate out from the normal, primary set of gears to or through the secondary set of gears. On our Bug, the fittings were not hooked up to anything.
I thought maybe the setup was for an external oil cooler and/or oil filter, but with the separation of the two sets of gears, any oil going through the secondary set has to come from somewhere else and this would just boost the pressure.
Now, to me, the wierdest thing of all is that this oddball bit of engineering bears what looks like a VW part number! 113.115.233A.
Does anyone know what this was intended for?

Secondary question: Our Bug will rgularly drop its oil pressure low enough for the light to come on when it gets warm, regardless of the oil level being full. I understand I need to check the oil pressure and oil control plugs on the underside of the engine (I've done that several times on other VWs), but I've also read the oil pump itself could be at fault. What does a worn out oil pump look like? The gears on this pump look fine -- no unusual wear markws, teeth still symmetrical, etc. Anybody know what I should be seeing if it was worn out?
OldPunk
_______
Keep yer hands on the road and yer eyes upon the wheel.
Quote 0 0
Ryan
That's an autostick oil pump.  The extra set of gears is to pump tranny fluid.  If they aren't connected then you're car was probably converted to standard 4 speed tranny.
The spot where most oil pumps experience internal leaks is at the end of the gears, where the two sets of gears are separated in your case.  Gear endplay should be kept as small as possible.  Considering you're running half your pump dry (no ATF through the second set of gears) the pump may be damaged.  I'd replace it with a normal oil pump and see if there's any improvement.  --Ryan
Quote 0 0
OldPunk

Thanks, Ryan. Right after I posted this I found my answer in the Beetle service manual. I am defintiely installing a normal oil pump, but maybe one of the higher-pressure ones.

OldPunk
_______
Keep yer hands on the road and yer eyes upon the wheel.
Quote 0 0