Gary:
My issue was simply the two wing nuts on the top of the raw water
strainer weren't tightened enough to prevent the air leak........ I
didn't need a new water straining system with a better gasket sealing, I
just needed a 1/2 to 3/4 turn on each wing nut, problem solved.
Took it apart in the Fall to clean it and didn't torque it down enough.
Won't happen again!
Bob Abbott
AZURA
C&C 32 - 84
Halifax, N.S>
On 2013/05/24 12:21 PM, Gary Nylander wrote:
A friend of mine had a similar problem on his motorsailor. He had
overheating problems, so took it to the mechanics at the yard in Key
Largo for its usual bottom job and the motor work. Cored out the heat
exchanger, ran through the whole water system (has a trans cooler in
line as well) and dropped it back in the water. Ran great, great water
flow at the dock, so we took it out. About a mile out, overheating! No
water. Back in, check everything again. Ran it at the dock, great
flow, put a load on it, great flow, ran for about half an hour at
cruising rpm with load, great flow. Took it back out - lasted a
mile.... back in again.
It turned out that there was a small air leak in the raw water
strainer, as Bob said. Why it would run at the dock and be OK, and not
at the same rpm out in the ocean is still a mystery, but my friend
(after blowing a good sailing week) decided a new water straining
system with better gasket sealing was in order.
All is well.
Gary
----- Original Message -----
*From:* Robert Abbott <mailto:robertabb...@eastlink.ca>
*To:* Dennis C. <mailto:capt...@yahoo.com> ; cnc-list@cnc-list.com
<mailto:cnc-list@cnc-list.com>
*Sent:* Thursday, May 23, 2013 10:56 PM
*Subject:* Stus-List Overheating 3GMD - the plot thickens
Don:
One more thing to check.....check to see that your 'o-ring seal'
on your raw water strainer is tight .....if it isn't, your water
cooling system will suck in air and not enough water to cool your
engine.
If you take the top off the strainer out to clean it, you might
not have put it back together tight enough. How do I know this? Daa!
Bob Abbott
AZURA
C&C 32 - 84
Halifax, N.S.
On 2013/05/23 11:13 PM, Dennis C. wrote:
Good suggestion from Rich. Even a new impeller can spin.
Also, there may be a suction leak on the intake side of the
pump. Disconnect the discharge at the pump. Start the engine
and check for flow there. (It won't hurt the engine to run a
couple minutes with no water flow.) Try to stop the flow by
blocking the hose with a rag or your hand. If the flow and
pressure are good, move downstream. If no flow or you can stop
the flow then the issue is the pump or ahead of the pump.
If the flow is good, disconnect the hose to the little elbow you
cleaned. Check for flow and pressure there.
Dennis C.
Touche' 35-1 #83
Mandeville, LA
------------------------------------------------------------------------
*From:* Knowles Rich <r...@sailpower.ca>
*To:* "cnc-list@cnc-list.com" <cnc-list@cnc-list.com>
*Sent:* Thursday, May 23, 2013 8:35 PM
*Subject:* Re: Stus-List Overheating 3GMD - the plot thickens
Suggest checking the raw water pump impellor to make sure the
bronze insert is not spinning inside the rubber impellor.
This can happen with a new or old unit and can fool you in an
inspection as the rubber vanes may look perfect.
Rich Knowles
Indigo. LF38
Halifax
On 2013-05-23, at 22:00, "Don Jonsson" <dbjons...@shaw.ca
<mailto:dbjons...@shaw.ca>> wrote:
Hi
I had previously sent out a message about an overheating
diesel. The culprit, so I thought, was the knuckle going
into the mixing elbow, because generally when I cleaned it,
it worked again. For a while.
So I finally took of the mixing elbow and gave everything a
proper cleaning. I checked the water pump. I checked all
hoses by blowing through them and the engine.
I put it all back together and it all worked and water pumped
like it is supposed to, except the water pump leaked a bit --
needed a new gasket, but I knew that and just wanted to see
if it would work. Got a new gasket and put it on. Started up
and no water.
I took out the thermostat and checked to see it worked --
slightly corroded but it worked, i.e. opened in hot water.
Put everything back together and started it up and a bit of
water but too much steam. Took the thermostat out and put it
in more carefully. Tried again, water running, no steam
everything is perfect. Ran it for a while just to be sure.
Turned it off. Waited a while (an hour) and started it up
again. No water.
So the problem is not the mixing elbow (and likely never was
as it wasn't that bad). Not the pump as it looks fine. Not
the thermostat -- I don't think although I will replace it.
The problem is sometimes the engine pumps water and sometimes
not. And I'm stumped.
This is a raw water cooled engine which makes things
different. Has anyone had a similar problem and ideas for a
solution.
Also, it seems hard to get part numbers for a 3GMD and the
local mechanic had to go find an old book. Is there any
place online to find part numbers for that engine?
Thanks to anyone that can help.
Don
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