In the instance I mentioned, it wasn't excess silicon rubber gasket, it was a bit of regular rubber gasket. It was quite a large piece, and mysterious as to how it got into the engine.


FSM? Factory Service Manual?

The flow of the oil system is described in our club wiki: Lubrication Circuit.

well i have the answer...
the pump seized and took teeth off the pump drive gear, which feels like it ate up the cam :(

So anyone in the CA area got a spare A15 cam??

I looked, they did use silicone on the oil pump... well i won't i use the aircraft gasket stuff and gaskets.

What causes the pump to seize up?

btw, my oil system is fine and worked properly, it's not it's job to protect against pump stoppage...

was your piece of rubber from an oil filter flapper?

I was afraid that it might have been something like that. Anytime that oil pressure goes from full to zero in one go it's usually something pretty serious.

Fortunately, this sort of failure is almost totally unknown in our Datsun A series, but I doubt that this knowledge brings you much comfort.

lol
I always get the good ones.

I know what some other other failure modes look like, and this is a new one, everything's fine, then no oilpressure, no odd noises or smells or cloud of smoke.

I blame the oil pump ;)

worst part is it will mess up your cam too, so it's not a simple pump swap.

You could use an A14 or A12A camshaft. The 85 hp A14 cam is probably the best stock cam. Or just call Crane, Iskenderian or any of the other California cam vendors and they will make you one.

Yes, it may have been an "oil flapper" piece, I didn't know about those, figured the oil filter pressure relief would be made of metal. I know the rubber was too wide and too long to have been the external oil filter o-ring. It appears that it gradually bunched up in the oil inlet (in the engine block) until it blocked the passage.


Pump siezure is rare. Possibilities:
* Some chunk of something got in their (improbable, unless the pickup strainer was broken)
* Internal wear of the pump. Over time tolerances grow, maybe enough to jam the gears? Is that possible?
* Distributor shaft siezed. Or distributor gear failed. This drives the oil pump.

I would guess the latter is the most probable. I had a slant six once, and while tuning it up had the distributor cap half-fastened. When I turned the engine with the starter, the dizzy rotor arm hit the cap, and surprise! instead of the rotor breaking the drive gear snapped (some slant sixes used a plastic drive gear).

on the a15 the oil pimp is driven directly by the cam isn't it? Sort of wish there was a plastic gear to thrash instead of the cam.

i guess this isn't getting fixed over the weekend.

Quote:

hah, nah its directly driven by the market for oily hoes

lol that's a good one ;)

you want to keep those hoes oily.

Hey, im facing this problem too. Whenever i turned the ignition key to "on", the meter moves from 0 to max, and back to 0 again. When im driving around, it never moves. It remains at 0. So....errmm..where shall i start troubleshooting first?

I would start by getting a non-electric oil pressure gauge, connect it directly to the engine and see what it reads.

If your oil pressure is really at 0, the engine will be making banging sounds as you drive it.