If it ain't broke...

[SailFysh]

Well it looks like my luck has run out. Over the past 3 weeks I have tackled several service items to make sure my boat was up in all the maintenance areas. Thanks to this forum I have learned a lot and things have gone slow but well. Replaced oil and filter. Replaced both fuel filters. Installed new March pump for AC. Then today changed the coolant even though what I removed looked fine. I just did not know how old it was. Now... You guessed it... I am overheating. I have read and re-
Read all posts about burping the system etc. I have tried several methods and still it climbs steadily to 160-165 then shoots up to 185-190. Since I have owned the boat she has never run hotter than 165-170 even in mid summer. Guess I will sleep on it and tackle again tomorrow.

 

[weinie]

Prime the coolant hoses going to the water heater with coolant.

 

[SailFysh]

Thanks. I did not try that.

 

[JK_Boston_Catalina310]

Did you try the Mainesail technique of replacing the bleeding valve and using a funnel with hose to bleed the system?

If not, check out the C34 tech wiki.

 

[dziedzicmj]

If you have the water heater, it may need fairly high revs to "burp" it (2500+ rpm)

 

[Stu Jackson]

If not, check out the C34 tech wiki.

It's somewhere in there, under Critical Upgrades link, maybe.

But here's the short way to get there:

Engine Overheating 101 - How to Burp Your Engine (Reply #6) http://c34.org/bbs/index.php/topic,4518.msg26462.html#msg26462

 

[SailFysh]

Thanks all. I read that Engine Overheating 101 at least 20 times yesterday. Not sure what I am missing... Maybe I dont know which hose to prime? I removed the big hose beneath the water pump until coolant came out, poured coolant into the bottom hose on the thermostat although it was already full and did not take much, revved the engine to 2500+ rpm several times... I tried it at least 7-8 times during the day and each time the same. Steady climb to 165 then fast climb to 190-195 and I would shut it down.

 

[SailFysh]

Did not try Mainesail technique as mentioned by JK Boston...

 

[SailFysh]

If you have the water heater, it may need fairly high revs to "burp" it (2500+ rpm)

I have a water heater and a heat exchanger. Are you referring to the heat exchanger hoses?

 

[SailFysh]

Was there any doubt? I read it all again, then followed your advice, cranked her up this morning and like magic she never climbed above 165. Thanks again all.

 

[Jongleur]

Glad you figgered it out. Apparently not your
problem, but I had a bad connection in the wire
from the sending unit to the gauge which would
do just what you said: slow up to 160 or so then
shoot up and peg at the highest. It went so quickly
that I properly guessed it was not thermal, but was
electrical. Replaced a continuous wire from sender
to gauge and the problem went away. Frustrating
while it was occurring.