[C38] Mor(on) Overheating

[tdtron at earthlink.net]

Hello David and group,

Burping with the thermostat out gets out a lot of air but you may introduce
more air re-installing the thermostat.  A hot engine should allow good flow
to burp engine allowing any trapped air to surface at the filler cap.

You mention seeing bubbles in the circulating water.  This isn't a good
sign if you had already allowed enough flow to burp the engine.  You may
have a leaking head gasket.  Have you lost water when everything was
running?

If you do have a head gasket blown from the cylinder or oil return ports,
you will need a new head gasket.  The engine oil supply to the head is via
a hollow dowel fitted with an "O" ring and that seldom fails.  If the
gasket is only blown from the cooling ports you can probably repair it with
a good radiator repair sealant like Bar's Leak but if the bubbles are
exhaust getting into the water jacket, you may have to replace the head
gasket.

Our engines are notorious for corrosion and rust buildup in the water
jackets.  Prestone makes a power flush system where you put a hose
connector in the cooling hose going to the hot water heater or to the heat
exchanger if you don't have a hot water heater.  You then use a caustic
chemical engine flush and let it circulate through the engine while the
engine is hot and running.  The water power flush is so you can totally get
that toxic waste out of your engine. It will initially come out looking
like muddy water.  The power flush is done with the engine stopped so you
can remove the pressure cap and let the mud geyser flow until the water is
finally clear.  I hope  you have good bilge pumps.

To refill the coolant, the petcock drain is sometimes difficult to connect
a filler hose to for bottom filling but you don't have to fill from the
bottom if you don't want to.  You can fill water only from the top, drain a
gallon of water from the bottom petcock, close the petcock and then top
fill from the top again with a gallon of antifreeze.  Top off again as
necessary as the engine continues to "burp" air bubbles out.  If you have
most of the bubbles out, the engine will continue to burp residual air with
the overflow container refilling automatically.  With the overflow
conversion I suspect you already installed, you won't get the corrosion and
rust again so your engine cooling system will now stay clean.  The recovery
system means that not only do you have a reserve of coolant, you also
isolate the engine from air so rust will be almost a thing of the past.

The fact that your pressure cap doesn't seem to allow flow in either
direction makes me suspect that you have either a gasket failure, or less
likely, a crack somewhere causing loss of coolant pressure.  Most
automotive garages have radiator pressure testers, maybe you can rent one. 
It just connects to the filler and you pump it manually like a ball pump
until the gage reads the same pressure as your pressure cap rating.  You
let the tester stay connected for around 30 minutes and see if it changes
pressure.  This test should be done on a cold engine so temperature changes
won't make false pressure reading changes.

Good luck,

Tom Troncalli




> [Original Message]
> From: <david at dlrfilms.com>
> To: Catalina 38 Listserve <listserve at catalina38.org>
> Date: 6/21/2011 9:08:28 AM
> Subject: [C38] Mor(on) Overheating
>
> So I found the drain plug at the lower port forward corner. Have not had
> the chance to do a flush and fill from the bottom. (Still a little
> confuzelled how I'm going to fill from the bottom.)
>
> I did take the thermostat out, and ran the engine with the coolant level
> about 1 inch from topped off. I could see a steady flow of coolant coming
> in from the thermostat housing to the forward inlet on the tank.
>
> I have noticed that I was not getting any flow from the two-way radiator
> cap into the overflow tank, and the previous owner had mentioned sometimes
> it would stop for no apparent reason.
>
> I fiddled with the cap for a while, wondering if it was clogged or jammed,
> but couldn't find anything, so I just removed the lower gasket and tried
> it that way.
>
> No luck.
>
> Plenty of flow through the cap and out to the overflow tank, but the
> engine temp still climbed in short order, yet the coolant itself was cool
> enough to stick my finger in.
>
> Considering I could actually *see* the coolant flowing, this was quite
> frustrating.
>
> Also, when I ran with the cap off, it seemed like their were bubbles
> coming up. It made me wonder if the system might be aspirating air, and
> (re)creating a bubble.
>
> Help?
>
> Meanwhile, drain, flush, refill.
>
> Argh!
>
>
> _______________________________________________
> Listserve mailing list
> Listserve at catalina38.org
> http://catalina38.org/mailman/listinfo/listserve_catalina38.org