95 geo metro 1.0 Rebuild and now I have no oil pressure.

[zims69s]

I have just overhauled my geo 1.0 liter engine. Everything is new, and the oil pump. When I installed the oil pump there was a small o-ring and a large one. The small one goes in the oil dipstick tube, but I have not a clue where the large one goes. So I put it all together and ran the engine and I do not get any oil pressure. But I have oil at the sending unit if I take it out and let the oil run on the floor, Even with a gauge it has zero oil pressure. My question is there a trick to these engines after an overhaul? The pump seems to be primed. It still worries me about the extra o-ring, does anyone know anything about this?

[geozukigti]

The large o-ring goes on the cooling pipe on the back of the engine where it goes into the back of the water pump. Did you install the oil pump gasket properly? If you put too much goop, it could flatten out and plug up the oil line. Also, did you install the oil strainer back in the oil pan? With the o-ring on it? Have you plastigauged your main bearings to check for tolerances?

[zims69s]

All the clearences are ok, pickup tube is on with seal, oil pump is primed. Does anyone know which hole the oil sending unit goes on. There are two of them on the front of the engine looking down, my sender is on the right side. I am not sure if it matters but I hope so.

[idmetro]

Here's a couple of links to some pictures that may help over on the team swift board.
http://www.teamswift.net/viewtopic.p...&view=previous
http://www.teamswift.net/viewtopic.php?t=4691