Engine Cooling Water Stops

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TomB
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Engine Cooling Water Stops

I have a 1988 36' hull no. 854 and after many years of great service, my engine has an issue.  I have installed a new cooling water rubber impeller, bleed the air out, and motored in and out of my marine three times this season.  When I started my engine to return yesterday, there was no cooling water coming out with the engine exhaust.  I shut the engine down.  First I removed the intake filter, water gushed out.  The rubber pump impeller also looked great.  With the hose off the top (output) of the heat exchanger, water gushed when I started the engine.  With the engine off, I opened the muffler petcock; no water came out.  I started the engine; and water spit out of the petcock.  I closed the petcock and then water started exiting with the exhaust as normal.  So the engine works fine now, but I don't feel like I fixed the problem and I fear it will reoccur at the worst time.  Does anybody have any ideas about what I am experiencing?  (last week I flushed out each end of the heat exchanger with a garden hose) 

I have one more crazy question.  I have what I believe is a Mark I from 1988.  In the next slip is another Catalina 36 as old as mine.  From a distance, my mast is clearly a couple of feet taller than his.  Do I have a Mark II tall rig?

Thank you all very much for your interest and input.

Tom Bozzi
Dreamer
Warwick, RI 

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Haro
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I believe you have air leaking in at the impeller causing it not to have vacuum suction.
What type of raw water pump you have. Most owners are converting to Oberdorfer.
With the engine off place a 4 foot hose on the water pump input and into a 5 gallon water bucket with water in it.
Turn on the engine and see if water is being sucked up from the bucket.
If you know how to do this - you can also inset water on the output side of the pump then turn on the engine and see if water is coming out. Be careful not to place a lot of water in the chamber where water and exhaust are mixed as your engine will be flooded with water.
Your model hull raw water intake through-hull opening has a grill that becomes clogged with sea growth. You would have to have a diver clean this. You can also remove the hose and place it into a bucket of water and see if water is being sucked in.
Hope you find the problem.

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LeslieTroyer
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Since you just changed the impeller I would first suspect  either the o-ring or gasket.   For the gasket it may be to thick or a piece of the old one is still there.  

If the cover is groved. Sand it smooth on a piece of glass up to 440 grit - with wet and dry paper (wet). 

If the cover is ok replace the impeller again - you may have gotten a bad one. 

Les

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

TomB
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Joined: 8/3/15
Posts: 10

Thank you Haro and Leslie for your replies.  Even though the engine ran well for the last two weeks, maybe another new gasket (and cleaning each surface) is in order for my Oberdorfer pump.  It's hard to understand why it would gush out of the heat exchanger exit (with the hose off) and then not out with the engine exhaust.  Since it works normally now, my investigation will be limited. 
Thanks again for your help!

Tom

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Chachere
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Tom Wrote "I have a 1988 36' hull no. 854 ....I have one more crazy question.  I have what I believe is a Mark I from 1988.  In the next slip is another Catalina 36 as old as mine.  From a distance, my mast is clearly a couple of feet taller than his.  Do I have a Mark II tall rig?"

Your boat is a Mark I (I have read that the MKII started  in August 1994 with hull #1368).   But Mark I models came either with the regular or the tall rig (our '85 MarkI #466 has the tall rig, for example). 

Wiser minds than mine have already weighed in on your engine saltwater issues, but just in case none of those suggestions work, there was a long discussion four years ago with a now-former member who has having issues with the aqualift muffler, and after much back-and forth it was eventually diagnosed as a crimp in the exhaust hose.  See www.catalina36.org/forum/technical-discussion/2-blown-aqualifts-need-reasons , and in particular see post # 25 there (photo of the offending portion of the hose) .

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

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pkeyser
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Posts: 659

Tom-

My focus would also be on the water pump- either too thick of a face plate gasket- and / or wear in the pump face plate from the impellor. Several years ago with our C30/M25- I had a similar intermittent water pump issue. It turned out to be the impellor had worn the brass face plate by about .005 inches- enough to weaken the pump to the point where just turning the boat direction under power or increasing the engine RPM could cause it to loose all suction. A new impellor, intake strainer, and raw water hoses didn't remedy the problem and it drove me crazy for the season. Only after finding the face plate wear, and sanding/polishing it flat again, did I stumble upon the fix.

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

TomB
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Posts: 10

Matt,
The information about my Mark I kind of blows me away.  So I do have a Tall rig.  Thanks!

Paul and Wendy,
Your pump information is something I will definitely keep in my back pocket.  It's one more thing to investigate.  Thanks

Tom

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Chachere
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Posts: 825

Tom -
According to this thread from a few years back, "the easiest way to tell is to measure the boom extrusion, which is 13'6" for the tall rig, 12'6" for standard. Unless, of course, in some weird, whacky way the wrong boom length is on your boat."
See  www.catalina36.org/comment/52803#comment-52803

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

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