Small hole warm water exit lower drive unit opposite drain plug.

[soulsalvation]

On the opposite side( right hand if looking towards the bow ) there is a small pencil diameter hole that is jetting out warm water when the engine running. My stern drive is 1 generation Alpha 1975 233hp 351 Ford Mercruiser (Cleveland I think)
I’ve never noticed water coming out of there before because water from the hose connector obscured that outlet. It looks machined in the housing and not a corrosion hole.
Does anyone know wether it’s normal or is there a cap or screw missing there?
Thanks to all who reply.

 

[Bt Doctur]

that is a drain hole for the shift shaft cavity. water from there could mean a leaking water pump /impeller housing/etc

 

[soulsalvation]

Thanks for replying. What is the purpose of that hole? It’s coming out at pressure but everything else seems to be working perfectly. Lots of water out of the elbows boot area. Engine water system pressure is good.

 

[soulsalvation]

Thanks Bt Doctur. You wouldn’t have links to the stern drive water flow system schematics by chance? I’ve already got the engine system. Ciao

 

[soulsalvation]

Do you think I can still use the boat one last time before closing her up for the season or will there be a catastrophic failure or something or other. Thanks again Pt Doctur

 

[achris]

That hole is as already said, a drain for the front of the drive. Water coming from the hole is not only normal, but it needs to happen. If the hole gets blocked up with dirt (VERY common), then the water can't escape from the cavity, and the first freeze results in a cracked housing. If you get OIL leaking from the hole, then yes, you have a seal issue somewhere.

It's part of the drive service to ensure that cavity drain hole is clear.

Chris.....

 

[soulsalvation]

That hole is as already said, a drain for the front of the drive. Water coming from the hole is not only normal, but it needs to happen. If the hole gets blocked up with dirt (VERY common), then the water can't escape from the cavity, and the first freeze results in a cracked housing. If you get OIL leaking from the hole, then yes, you have a seal issue somewhere.

It's part of the drive service to ensure that cavity drain hole is clear.

Chris.....

thanks for responding Chris. So it’s normal that it’s coming out with pressure and not just water leaking out fronm the drive being submerged in water? Bt Doctur stated that it’s likely a leaking gasket from the water pump housing. because i’ve never noticed it before it had me a little perplexed.So it’s all good to run that way. thank you again.

 

[achris]

I've seen water come out of that hole almost a metre, and it does look like it's under pressure. The only pressure it's really under is gravity, and the 'head' that has developed. Once you shut the engine off the water should keep draining out for a bit until the cavity is empty. If you're in doubt, post up a video.

Chris.........

 

[soulsalvation]

Thanks again for responding Chris. Out of curiosity...where is that water coming from if it’s not submerged in the water? I began to ponder the idea and realized if the water was warm then it must be coming from the exhaust manifolds and not from a leaking lower water pump unit which was suggested in which case it would be cold water. This old cruiser is full of mysteries! thanks again.

 

[soulsalvation]

i will take your suggestion and video the drive in action tomorrow as i change the engine oil before her big sleep. thanks for your help.

 

[achris]

The water will be warm, when you pull the drive for the winterizing service, have a look at the exhaust cavity in the drive, you'll see it's a clear path straight to that hole...

Chris....