circulating pump (test ?)

[mercrude]

how can I test the water circulating pump whithout removing from engine

 

[oldboat1]

Re: circulating pump (test ?)

See your other post for at least one suggestion (operate without the cap on the heat exchanger and look for water movement in the exchanger.) Don't do this when the engine is at temperature, of course, and there is pressure in the system.

 

[mercrude]

Re: circulating pump (test ?)

Ive done this took cap off started boat temp guage goes up and water splashes up and out but does not circulate or move just upward

 

[airman]

Re: circulating pump (test ?)

I think that the problem is your exhaust manifold. I've got an '82 470 and the manifold is fresh water cooled. You mentioned that it was cracked and you repaired it - BAD IDEA - . I tried that trick on my elbow and it lasted about a day. I know it looks pricey but try comparing your one small manifold to the four big ones on a boat with twin V8's and that might take away some of the $ting. I could be wrong but what I think is happening is that hot exhaust is forcing its way into the coolant. That might also give you the air bubbles mentioned elsewhere in the suggestions. While you have the manifold off, take a good look at the elbow and also look down the rubber bellow: the exhaust tube going into the leg is aluminum and the stainless steel screws for the flapper valve corrode the tube around them. I think I was able to repair that tube with JB which is good because you can't replace that tube without pulling the engine. Good Luck! BTW you've got a great engine, mine has 1300 hours on it and it still pulls a 21" stainless prop past 4200rpm on my 3000# boat.

 

[Bondo]

Re: circulating pump (test ?)

Sounds like a Stuck T-stat......

 

[airman]

Re: circulating pump (test ?)

Sorry, KISS principle - check the T-stat first. I would be pretty worried about your manifold though. If it leaks, all of your coolant goes into the exhaust. If it happens when the engine is shut down it then works its way past the exhaust valves and into the oil pan. This happened to me on my Chrysler and after big $, big time and some bent pushrods the engine runs again but its never been the same. Mine was worse though because the manifolds are seawater cooled.