Engine help

[Manana5]

Dear cruisers, my family and I have recently purchased a 1973 Wauquiez Centurion 32 and are working to sail it across Med to northern Aegean, currently in Peloponnese and heading for Corinth canal, going east.
We keep having issues with our engine. It is not the original one, it was changed in 2007 with a Volvo Penta D1-20. It seemed in great condition and would start instantly, no issues. We serviced it before starting the trip. In calm weather it can run for days with no issues (we tested this as there was no wind all across Corsica, Sardinia and Sicily). However as soon as there are waves or the boat is heeled, the overheating alarm starts going off. Sometimes it will go off so fast, I don’t even know how the engine had time to actually overheat.
We have checked it over and over and nothing seems wrong on the inside but it keeps doing that. Unfortunately it means we are without engine when we need it most - in rough conditions or head winds. I’m really worried about the next leg of our journey because we will encounter head wind at least for 30 miles as we round north. Also our boat with the current sails does not go well upwind so we were hoping to motor that stretch. Has anyone had a similar engine issue before?

[Paul L]

How is the exhaust water flow before and at the overheating?

[model 10]

You may have air or low water in the cooling system. Rough conditions or heeling could uncover the temp bulb and you would get a light/warning, right away.

[Fore and Aft]

Sail drive or shaft driven? If it’s a sail drive have you dived on her to check the inlets on the sail drive are clear? If it’s shaft driven how low is the pick up? I have seen a pick up that was to high on a converted lifeboat and every time it got rough the motor overheated.
Cheers

[Manana5]

It’s a shaft, here is a picture from sailboatdata:
https://sailboatdata.com/sailboat/centurion-32
Sorry my English is not perfect when it comes to boat terms, could you explain what do you mean by ‘pick up’?

[Gary Mc]

Hi I believe by " pick up" he means the thru hull for the cooling water inlet.



If it only happens in rough conditions and very quickly might you have a loose connection on the wire to your temperature sensor? That might cause the alarm to go off?


Good luck finding the problem.

[NYSail]

Have you used a hand held temp gauge to actually check the engine temp? Like was mentioned you also want to watch the water flow in the exhaust.....

Good luck

[DefinitelyMe]

I agree with previous suggestions. I would, in this order:

1) check coolant level
2) check that outflow is sufficient. Feel it with your hand. If it is very hot, or if you are getting steam from the exhaust then flow is probably insufficient.
3) check electrics.
4) check thermostat

Yes i have had exactly this problem. For me the problem was a gummed-up heat exchanger causing insufficient raw water flow.

[Manana5]

Originally Posted by DefinitelyMe

I agree with previous suggestions. I would, in this order:

1) check coolant level
2) check that outflow is sufficient. Feel it with your hand. If it is very hot, or if you are getting steam from the exhaust then flow is probably insufficient.
3) check electrics.
4) check thermostat

Yes i have had exactly this problem. For me the problem was a gummed-up heat exchanger causing insufficient raw water flow.

Thank you, will go through this checklist. What causes insufficient water flow and how did you fix it?

[NYSail]

Also do neglect to inspect your mixing elbow...... depending on design they can get pretty clogged over time.

[Manana5]

Originally Posted by Manana5

Thank you, will go through this checklist. What causes insufficient water flow and how did you fix it?

Sorry, I reread your comment and got it. I’ve been lacking sleep lately.

[DefinitelyMe]

Good luck. For me it was mainly old zincs in the heat exchanger. Had to remove it, dismantle and clean it out.

I second the suggestion of checking the mixing elbow. Those things are basically disposable. At least for us.

If your access, like mine, sucks, you can get an idea of where a restriction might be from blowing through hoses, without having to dismantle everything and peer into it.