over heating engine

[swillyboy]

i have a benateau 361 with a over heating problem after an hour of motoring the alarm sounds i turn off engine and find i have lost coolant. i have removed the heat exchanger and cleaned it but the same thing happened next time out. i do'nt think it is the stat or pump any ideas.

[erps]

I"ve experienced a few overheats and each has either been an obstruction to the raw water circuit (sea strainer and before) or worn raw water pump impellers. That's where I would start.

[Faster]

Another good candidate for obstructions is at the mixing elbow-where the RWC enters the exhaust system.

However if you're losing coolant - do you see/smell a leak? If the coolant is disappearing without evidence of leakage you may be burning it or losing it to the RWC side (though generally the RWC ought to run higher pressure than FWC). Do you see any evidence of whitish 'smoke' that might indicate you're burning it?

[jackdale]

Head gasket?

[captflood]

GREETINGS EARTHLINGS; Have you checked that the pipes are free from kinks or are not blocked with debry or silts pipe cleaning types of bottle cleaning brushes checking all bends and juntions are clear . GO SAFE

[Tempest]

Do you have coolant in your bilge after shutting down? No sign of leaks? Good water flow out the stern?

Is that Londonderry, Ireland??

[HDChopper]

Check your oil & make shure it didnt turn to milk.

[Semloh]

1 hour is a long time.

I would think that you are losing coolant then getting hot.

Cracked Head, Blown head gasket.

If you are losing it into the cylinders you can sometimes get a faint coolant smell in your exhaust and most likely your oil will change to a milky color.

[swillyboy]

all lost coolant has ended up below engine in bilge i have cleaned elbo also cant find any holes plenty of sea water pumping out a stern no milky oil still at a loss, could it be a faulty circulating pump ?

[HDChopper]

set it all up for a run, then watch the eng compartment while you run it for an hour or so sounds like the leak / pinhole only gets going once pressure builds up , if all coolent is in bilge .

Of course if eng even seems to get hurt shut down...

Sounds like a bad clamp / bad fitting / valve / pinhole in anything , keep eye on pump , pump bearings take pressure to leak there should be a weep hole some where on the pump around the pump bearing ( well just about all coolent pumps do)...