Engine Over Heating

[Guest]

I recently drained by Yanmar 2Gm20F fresh water system and recharged it with an anti-freeze solution. The engine now over-heates after 10 minutes. I replaced the thermostat. Suggestions

 

[Jim McCue]

over heating

Check to see that your antifreeze level is almost to the top of the block. Perhaps the thermostat was closed when you filled up the system and you maybe then didn't put enough antifreeze in. Just a thought....

 

[Roy Mosteller]

Flush With Radiator Cleaner?

Did you use a good radiator cleaner and then thoroughly flush the system? Might possibly be a clogged heat exchanger. It is surprising how much rust and flakes can be removed during cleaning and flushing process.

 

[Jim McCue]

overheating 2

adding on to the prior posting... A couple years ago I took out the heat exchanger by removing the facing "cover" and sliding it out. Not difficult to do - but First - drain your anti freeze and siphone out your raw water or you'll have a messy puddle.Pulled out the exhanger and washed it down in Lysol Direct- used pipe cleaners to flush/polish the various conduits in the "gattling" assembly. If you go this route, buy the replacement coverface gasket in advance for your reassembly. Good luck

 

[Allen]

Fresh water intake

I am sure you checked but any chance the fresh water intake might be clogged?

 

[Doug]

Most probable cause

We did the same thing last season and things happened exactly as you said to us as well. We found that we did not have system completely full. Try "burping" the thick but short section of hose going to thermostat housing. Also, sometimes an air bubble can develop in the hose system that goes to and returns from your water heater (if you have engine heated water heater in your boat). It takes some doing to get system completely full but that will most likely be the culprit...it was ours.Doug