1984 Mercruiser 228 Alpha High Speed overheat

[othelloears]

Engine is overheating at high speeds again. Idles great but at 3k I am overheating in 2 minutes.

I replaced the drive pump, thermostat, elbows and manifolds last month and was running perfect until last week.

The only thing I can think of is sucking up mud in shallow water the day before. (Its full raw water cooled)


My question is when these things clog where does it happen? i have heard that there is a screen in the power steering cooler?

The only other thing is the water pump on the engine is not pumping enough. Is that common? With my GM car experience these pumps usually wer out and leak before that stop pumping.

Any guidance is appreciated

 

[series60]

Re: 1984 Mercruiser 228 Alpha High Speed overheat

Have you ever pulled the block drain plugs to see if the water jacket is full of crud? I have the same vintage 228 with 850 hours on the motor and when I pulled the block drains they were full of crud! I routinely pull these plugs and back flush the water jacket out through the thermostat housing.

 

[Don S]

Re: 1984 Mercruiser 228 Alpha High Speed overheat

Vinyard Sound

Assuming you boat in salt or brackish water, you may have manifold and risers plugging up and in need of replacement.

 

[othelloears]

Re: 1984 Mercruiser 228 Alpha High Speed overheat

Does anyone know if there is a screen in power steering cooler?

Has anyone seen a water pump(engine) fail without leaking (no water output)?

 

[Don S]

Re: 1984 Mercruiser 228 Alpha High Speed overheat

Does anyone know if there is a screen in power steering cooler?

No screen.

Has anyone seen a water pump(engine) fail without leaking (no water output)?

Many times.