Replacing all of the belts and the water pump on my 1993 van. Everything went pretty smoothly, really. I got it all put back together, started the engine, and oil started pouring out onto the ground, seems like it's coming from behind the water pump. I took the belts off, removed all the timing covers, and reinstalled all the belts and tensioned them, then started it back up without any timing covers, to confirm whether there is any oil coming out of the seals. The new crankshaft and camshaft seals are NOT leaking, but oil is dripping rapidly from around the new water pump's drain plug (which is installed quite tightly) and seems to be coming out from between the water pump and the engine block. It's definitely coming out of the lower dowel pin hole, which is of course a useless +0.7 mm oversized cast hole (not reamed or even drilled) in this Chinese knock-off water pump. But apparently all replacement water pumps for these vehicles share this construction, and nobody else is having huge oil leaks like I am seeing. While removing the old water pump, I did notice a few drops of oil coming out along with coolant that puddled on the floor. I assumed this was oil from the old camshaft seal that leaked and got trapped in the nooks and crannies around the old water pump. I may have been wrong. Where could the oil be coming from? The only fluid that's supposed to flow through the water pump is water/coolant, right? No oil. Why would the water pump leak oil?
Reese, there should be no oil in the water pump, only coolant. Are you sure the cam and crank seals are ok?
The only thing I can think of is you may have disturbed the oil pump cover seal during the water pump replacement. Possibly a screw was loosened on that cover or is missing? One of the plastic cover bolts holds it down and is out? The majority of that cover is just sealed with silicone and a few o-rings. And one last thing- My head gasket blew out randomly at the outer edge where the high pressure oil passes through recently. I swore the oil was coming from where you are describing til I cleaned it all up and had the exhaust manifold off. The oil hugged the block just right to drip from where you say yours is.
I just got my block back from the machine shop today and I can see where your leak is from. There is an oil galley that is sealed off by the water pump. That gasket is probably damaged in this area.
The water pump seal groove was too deep. Only 0.1 mm shallower than the gasket. I RMA'd it and the replacement had an in-spec groove. No leaks now, happy Sambar.
