Can anyone take a picture of where the oil filler neck is located and what the cap looks like? It doesn't appear to be a threaded neck, but the cap that the parts store computer calls for is threaded.

I also want to make sure it IS the oil filler neck I'm looking at. Sticks above the engine, maybe 1.5" diameter at the end, the tube appears to go to the back of the engine.

It might be the trans filler though, dunno. '87 Vulcan here.

 

The oil filler neck should be about 1.5" diameter, and the cap is threaded, with a ratchet the releases when the proper torque has been reached. It should go into one of the valve covers.

The transmission filler is just the dipstick tube for the transmission, and is about the same size as the oil dipstick tube.

Are these missing on your van?

 

AFAICT, all Aerostars (all engines), and most Fords of that era, used the same, threaded oil filler cap: Motorcraft EC743.



The common failure is its anti-over-tighten clutch mechanism, which when it fails forces you to destroy the cap to get it off the filler neck. I've had to use water pump pliers on more than a couple of them over the years, to remove them.

I've tried the Stant replacement, and I highly recommend buying the Motorcraft part; it's much better constructed, and it looks better too. $5-12, depending on where you buy it.