OMC hue16c problem owerheating high RPM in neutral temp dec and engine is overcooled

[johny56]

Hi all,

I Have 1968 OMC Hue 16c 3.0V6

i install a new impeller and check thermostat everything works fine.

after a 3min. driving my temperature rapidly increase to 120degree celsius aprox 240F. after i stop the boat and stay with running engine on Neutral my temperature after 5 min goes to 140F.

Do you have any idea where is problem?

Thank you

 

[Scott Danforth]

welcome aboard

never let the temp get that high.

my first thougth is you do not have enough flow. when you replaced the impeller, did you just replace the impeller, or did you also replace the water pump housing?


the fact it cools down indicates there is some flow. however you do not have full flow. you either have a blockage somewhere or you have a loss of flow.

 

[southkogs]

What Scott said, and also - Grease the swivel bearing (fitting on the front of the out drive under the plastic cover). You may be getting exhaust gasses into your system causing the overheating.

Welcome aboard!

 

[THE BEEF]

I think SouthKogs hit it right, swivel bearing seals. Exhaust gasses are being sucked up in the water pump due to swivel seals. I had the same exact thing happen to me on my 800 stringer, a OMC mechanic told me to give the swivel bearing about 12 shots of grease and see if it helps, after that no over heat problems. I changed the seals at the end of the season and had no problem since.
Take Care