automotive water pump ok or no ???

[Rich Novak]

72 omc sterndrive 225 hp
is it ok to replace the water pump with a automotive type , the old one has G M stamped on it.
The old pump was weeping from the weep hole.

The motor runs well I replaced the Thermostat sending unit and a auto type pump now the guage reads hot after running a while

I think t he impeller in the o/d is good it has the tell tale water stream .

I also found out someone took the thermostat out.

what else would make it run hot

I am pretty sure the head gaskets are ok no water in oil, runs very well

I havent checkedthe timing yet But as I said it starts and runs very well

Thanks, Rich

 

[bruceb58]

Re: automotive water pump ok or no ???

Nope, need a marine type.

Clogged up manifold/risers can cause it to run hot.

 

[southkogs]

Re: automotive water pump ok or no ???

When was the impeller changed last on your Rich? On mine, it got a telltale (more of a random spray from the trunions ) even when the impeller wasn't functioning right.

 

[Howard Sterndrive]

Re: automotive water pump ok or no ???

is it running hot at idle, or up on plane?

 

[888]

Re: automotive water pump ok or no ???

Water coming from the weep hole says the water pump is bad. Any engine circulating pump will work if it fits. Might have to plug the heater core line off the pump. But it will work.

 

[mrdjflores]

Re: automotive water pump ok or no ???

typically, automotive water pumps will work, but not that well.
automotive water pumps are "pushers" in that they build up the water pressure and push it though your engine.
your typical marine engine water pump is a "recirculating" style, that doesn't build up and pressure, just aids the pump in the outdrive to recirculate the water through the engine..
if you compare the 2 side by side, you'll see the vanes in the automotive pump run at an angle, while the vanes in a marine pump are straight....

of course, this was based off of a merc 888 (ford 302) setup

 

[bruceb58]

Re: automotive water pump ok or no ???

Any engine circulating pump will work if it fits. Might have to plug the heater core line off the pump. But it will work.

Until the bearing fails or the impeller corrodes off since it is not a marine pump.

 

[888]

Re: automotive water pump ok or no ???

Until the bearing fails or the impeller corrodes off since it is not a marine pump.

That will happen to the marine pump as well. I have an automotive water pump on my 350 chevy mercruiser and its been doing great for 14 yrs now and least 600 hrs

 

[bruceb58]

Re: automotive water pump ok or no ???

That will happen to even the marine pump.Got an automotive water pump on my 350 chevy mercruiser and its been doing great for 14 yrs now.

Different bearing in a marine pump. Wouldn't last more than a month in salt water. In an auto application, the bearing gets lubricated by the antifreeze. Unless you have closed cooling running antifreeze, running a raw water pump even in fresh water is anot a good idea. You are just lucky. The next guy that takes your advice might not.

http://www.boatfix.com/how/marineeng.html

Unlike their automotive counterpart, a marine pump works in an open cooling system. This type of system is extremely corrosive to the pump. Therefore, the pump must be altered for longevity. A marine pump has a special ceramic seal, stainless steel backing plate, and a bronze impeller to resist corrosion. An automotive style pump, with its stamped steel impeller, would fail due to corrosion in a short time.

 

[Rich Novak]

Re: automotive water pump ok or no ???

When was the impeller changed last on your Rich? On mine, it got a telltale (more of a random spray from the trunions ) even when the impeller wasn't functioning right.

Not sure if it was changed I just got the boat a few months ago, started to restore it , Thought I had it close, then just for fun I changed the sending unit on it then ran it a a high speed to see if it would make the guage work better, the it started to overheat, shut it down pulled the thermo housing and ala no thermostat. Got one today will see if it made a difference, i will also clean the manifolds the best i can. there is a lot of scale in them.
Thanks, Rich

 

[bruceb58]

Re: automotive water pump ok or no ???

i will also clean the manifolds the best i can. there is a lot of scale in them.
Thanks, Rich

If they are that scaled, best to get new ones.