[C320-list] engine overheating

[Matt Curtis]

The Yanmar engine manual says to replace them anytime you remove the tube from the housing.
   
  -Matt

Jon Vez <jonvez at comcast.net> wrote:
  Jeff,

I had added the heat exchanger to my maintenance list so the timing is
perfect. Is the gasket reusable or should I order one before I open the
exchanger? Thanks!

Regards,

Jon Vez
Solstice #582

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of
catalina at thehares.com
Sent: Wednesday, June 25, 2008 2:29 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] engine overheating


Hi Matt,

All the responses so far are good info.

Our raw water pump developed a leak where the pulley shaft enters the
impeller area. We have the Johnson pump, and it has a little $2 rubber
bushing that forms this seal that could be pulled out with needle nose
pliers and replaced to stop the leak. Your hull has a slightly different
pump, but you may still have a similar rubber seal that can be replaced.

The raw water heat exchanger is a topic that hasn't been discussed much
here. This year, I removed the 4 nuts holding that cover in place and
took a look to see what condition the exchanger was in. To my surprise, I
saw a portion of a leaf laying across a few of the tube intakes. If you
had any blades of an impeller break off, they'd be in there too as the
cooling tubes are too small for much debris to go through.

Something I didn't fully understand was that there is a rubber gasket on
the cover that divides the tubes into 2 sections at rougly 60/40 with the
raw water entering the smaller section. Since the outlet is at the back,
it seems that 60% of the tubes don't get water flowing through them for
cooling?

Perhaps, this is a way to allow the engine to be used in different
applications with different temperatures of cooling water available simply
by supplying a different front inlet cap?

Anyway, this makes it seem like any debris in the smaller chamber could
have a serious effect on the heat exchanger's ability to do its job. If
you haven't removed this cover before, it's simple. No springs or ball
bearings are poised to shower your cabin and the amount of water in
there is very small. Also, this doesn't open up into the antifreeze
loop, just the raw water loop, so it's a simple procedure.

Cheers!
-Jeff


> Hi, This past Sunday, the engine was running hot and eventually the temp
> alarm atarted sounding. I shut her down and waited to open the engine
> hatch.

> I noticed a little bit of water seeping out from under the forward
> engine compartment hatch, and when I looked, I could not identify where
> it came from.
>
> I troubleshooted from the raw water inlet to the water pump - all is
> fine. Should my next step be to look at the mixing elbow? I've read
> that deposits can build up, leading to less flow and ultimatley
> overheating.
>
> I'm worried because thw elbow is covered in heavy duty Al foil,
> presumably because the previous owner found or assumed a leak...I'm
> scared as to what I might find!
>
> Any thoughts/tips/ideas?
>
> Thanks!
>
> Matt Curtis
> Tortuga, #541





Matthew Curtis
mcurtis_6775 at yahoo.com