Surfer69

My water pump went bad and when I removed it there was and extra hole in the block on passenger side below the two bolt holes. This hole was plugged up so I cleared it with screwdriver and saw nothing but oil. The gasket has extra hole in it too. So my question is what is this hole for? I'm thinking it might be for lubricating internal pump bearings which if mine was clogged might of caused pump failure?

norvalwilhelm

There is definitly NO oil hole to lubricate the water pump bearing. The bearing is a sealed unit and needs no oil.
I don't know what the extra hole is for but it is not oil.

Ken73

The extra hole is the bypass hole.. what it bypasses, I can't remember. On high-perf water pumps though, you'll find that hole blocked or missing...

Twin_Turbo

You mean the lowest one on the pass. wp mounting pad




It's not used on our engines but some waterpumps have a passage for that hole in it like the edelbrocks


[Modified by Twin_Turbo, 1:36 PM 2/26/2003]


[Modified by Twin_Turbo, 3:18 AM 2/27/2003]

Surfer69

The AC mount makes sense except I could swear there were no threads.

Twin Turbo you took back your AC statement.


[Modified by Surfer69, 7:37 PM 2/26/2003]

Twin_Turbo

I edited because I typed befor I thought and there's no thread in there :)

jackson

It is a water bypass hole ... period.

1979toy

The lower hole in the photo shown by Twin_Turbo is the water bypass hole. It's purpose is to help the engine warm up quicker by recirclulating hot water back through the engine. Once the engine is warmed up it becomes a hinderance to proper cooling. Many aftermarket pumps have this hole blocked to keep the engine from returning hot water to the engine without going through the radiator.

Twin_Turbo

Well it's not used on all engines, on 82's the hole is plugged and the WP doesn't even have the hole.

It's certainly a bypass, I think it's to prevent cavitation

Surfer69

I wonder why mine had oil in it?