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1988 57L OMC Cobra chewwing up impellers

rost5501

New member
I am a new owner of a 1988 Bay

I am a new owner of a 1988 Bayliner with twin 5.7L w/ omc outdrives. The port outdrive keeps chewing up the impeller. I have replaced the impeller twice after running for only 1 hour each time. I replaced the entire waterpump assembly the first time and just the impeller the second. Is any additional lubricant required for these impellers or are they just cooled/lubed by the water passing thru.

I did take the entire waterpump assembly off and briefly start the engine to see if any debris came out and some did. After a few seconds no further debris came out.

Any suggestions?
 
"Wanted to add some additional

"Wanted to add some additional information.

This engine (port) runs 10-15 degrees hotter than the other while under a load. This may be nothing more than the gauge/sending unit being off. Starboard engine runs at 170-175, port engine runs at 180-185 while under a load.

Also at low RPMs (promarily in no wake zones) the port engine heats up. When the temp gets to about 190-195 I shift into neutral and rev the RPMS to about 1200 and cool the engine back down to about 170-175. Then put back in gear and try again.

I plan on taking off the oil cooler and checking for debris and/or blockage later today."
 
pulled the oil cooler off yest

pulled the oil cooler off yesterday and the inlet opening of the cooler was crushed. I would say 40-50% of the diameter was restricted. I straightened the opening back up (didn't even crack the housing)and reinstalled. Hope this will improve my running warn at low RPM problem. A few dried up zebra muscles where in the cooler but tubes looked pretty clean.

I keep having a problem with getting the water pump to seal. When ever I take off the housing to inspect and/or replace the impeller. I keep having trouble getting the pump to actually pump. I am not sure if the o-ring is not sealling or what. With the water pump cover off the impeller rotates normally. I assemble the water pump in the water so that the pump is primed. I even fill the water inlet hose to the t-stat housing in an attempt to eliminate some of the air in the system. When I start the engine the pump seams to pump for 1-2 seconds and then runs dry and begins to feel hot to the touch after 30 seconds.

Any suggestions? I am thinking of using a sealant along with the water pump housing o-ring

can anyone tell me what the rubber line that plugs into the pump housing is for. Is this a exhaust gas passage?
 
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