[C320-list] Another Perkins M30 Overheating Help Thread

[Paul Hetherington]

Thanks Dan.  We did try a bypass loop which didn't seem to help, but the
real issue seems to be that we hadn't purged the coolant system properly.
After flushing out the bubbles in the heating system we achieved the
following results (these are all under load at the dock).

2700 for 15 minutes stabilized at 185
2850 for 15 minutes stabilized at 190
2950 for 10 minutes heated up to 205 and was still going up when shut down
- not no overheat alarm!
2000 for 10 minutes cooled down to 170
2700 for 15 minutes stabilized at 185

Not sure why it shot up at 2950, but our normal cruising is 2700 so until
we get a chance to do a full day of testing I am going on record as saying
the cooling system purge has helped.  We should have tried that much sooner
in our steps, but now we know.  For those wondering we used this from
Amazon:
https://www.amazon.ca/dp/B01I40ZQWE?psc=1&ref=ppx_yo2ov_dt_b_product_details
The red fitting and the angle extension worked perfectly.  Best $30 spent.

Thanks to all for your very useful comments.

Cheers,
- Paul.
----------------------------------------------------------------
Paul Hetherington
Seasun 1994, Hull #155

On Sat, Jun 10, 2023 at 10:14 AM Dan Winsor via C320-list <
c320-list at lists.catalina320.com> wrote:

> I believe it is possible to get an air trap in the heater hoses to/ from
> hot water tank. Do you think a temp short bypass loop is worth a try?
>
> On Sat, Jun 10, 2023, 10:51 Dave Hupe via C320-list <
> c320-list at lists.catalina320.com> wrote:
>
> > Don't  believe it is possible to "remove the raw water hose from the
> > exhaust elbow and run it overboard". It is a very short rubber nipple
> > attached to the exhaust elbow that is part of the rear rubber boot
> > connected to the rear of the heat exchanger tank/tube.
> > Dave Hupe
> > 1994  C320 #32
> > Holland,  MI
> > Sent from Yahoo Mail on Android
> >
> >   On Fri, Jun 9, 2023 at 9:18 PM, Dan Winsor via C320-list<
> > c320-list at lists.catalina320.com> wrote:   Hey all, this is a good one.
> > So.... now that we have confirmed fresh water
> > flow via clear hose section (great idea), let's focus on heat transfer.
> The
> > fresh water gains heat from circulating around the cylinders and dumps
> heat
> > by transferring to the raw water via the heat exchanger and the hot water
> > heater via a coil located within. Those two circuits are parallel flow
> and
> > the hot water heater will get less flow due to smaller hose size. Does
> the
> > hot water heater get hot?
> > The engine heat exchanger is the primary heat dump of course. Although I
> > have not had cause to open mine, I assume it to be a shell and tube type
> > exchanger where raw water runs thru tubes from the fwd end to the aft end
> > of the exchanger and the tubes are surrounded by fresh water being
> > circulated by your new engine water pump. The radiator cap being on top
> of
> > the exchanger shell insures that if the water level is near to the top
> then
> > the likelihood of airbound condition is minimal. The expansion tank being
> > even higher pretty much guarantees it. Have you run with cap removed and
> > seen flow thru the shell?
> > The wet exhaust is a good indication of raw water flow but can be
> somewhat
> > hard to differentiate good flow from low, especially with the pulses from
> > the muffler. I would second the suggestion to resort to a contact
> > thermometer and start tracing the heat. I frequently grip the hose
> leaving
> > the raw water pump (cool to touch) and the hose entering the exhaust
> elbow
> > (quite warm) during my engine testing prior to launch.
> > Here are some additional suggestions....
> > 1. monitor the expansion tank and verify that level rises as engine heats
> > and returns to prior level as engine cools. this will verify proper
> > operation of the radiator cap and the plumping between the cap and the
> > tank. should eliminate air concerns.
> > 2. when eng temp starts to climb, try running hot water and see if that
> > stabilizes or slows the rate of increase.
> > 3. remove the raw water hose from the exhaust elbow and run it overboard.
> > Cob some plug on the elbow where the hose was attached. This will
> minimize
> > back pressure on the raw water pump and create more flow thru the tubes
> > thereby transferring more heat. This will also eliminate the exhaust line
> > from being a cause. Of course exhaust flow will be louder and get hotter
> so
> > don't run that way too long.
> > 4. remove the large rubber end caps at one or both end of the heat
> > exchanger and clean the inside of the tubes with a bottle brush. fouled
> > tubes cant transfer heat well.
> > 5. verify indicated eng water temp with contact thermometer.
> > Sorry if I repeated any testing you have already done. I also have the
> > perkins and have a vested interest in your issue. Lets solve this thing
> and
> > save your trip!
> > Dan Winsor
> > Lucky Devil #109
> > Mattapoisett, MA
> >
> > On Fri, Jun 9, 2023 at 1:20 PM Paul Hetherington via C320-list <
> > c320-list at lists.catalina320.com> wrote:
> >
> > > Jeff and Dave thanks for your comments.  Thanks for sticking with me on
> > > this.
> > >
> > > Dave, you are correct we are in Salt Water and have replaced the
> exhaust
> > > elbow.  It was relatively inexpensive and easy to do so it was high on
> > the
> > > list.
> > >
> > > Jeff, we may very well have air in the system it sounds like.  After
> > other
> > > fixes we may not have been focusing on getting it all out well enough,
> > > giving us the impression other fixes didn't work?  Going to play with
> > ways
> > > to eliminate it.  I'm not sure I understand the funnel method you
> > mention,
> > > but I am doing some research.  Also looking into whether a pressure
> > tester
> > > would be of value.  Dave mentioned 7psi.  Gonna chase that down.
> > >
> > > We did think perhaps we were over propped (good suggestion), but after
> > > working with the outfit that built our prop up here in Naniamo (he was
> > very
> > > helpful) it actually appears we may be under propped which is resulting
> > in
> > > our not achieving expected speeds and thus wanting to push the revs up.
> > We
> > > are working with that as separate issue and will be re-pitching after a
> > > haul out in 2 weeks.  Hopefully that doesn't exasperat our overheating
> > > issue, but at least we will be able to achieve a higher speed at the
> > lower
> > > rpms we are currently forced to operate under.
> > >
> > > Will report back.
> > > ----------------------------------------------------------------
> > > Paul Hetherington
> > > Seasun, 1994, Hull #155
> > >
> > > On Fri, Jun 9, 2023 at 8:48 AM Jeff Smith via C320-list <
> > > c320-list at lists.catalina320.com> wrote:
> > >
> > > > You might try running the engine without the cap on (apologies if
> this
> > > has
> > > > been suggested). It sounds like air in the coolant. There is also a
> > > > no-spill funnel that you can use with coolant to make sure there is
> no
> > > > trapped air. This involves filling the funnel with coolant and
> running
> > > the
> > > > engine and letting air bubble out. It might be getting into the
> system
> > > > through the cap.
> > > >
> > > > Is it also possible you are over-propped? I know you just installed a
> > new
> > > > prop and the problems also just started. Either too much pitch or
> > size? I
> > > > am sure, based on the list of stuff you have replaced, that this is
> not
> > > an
> > > > issue. But, I have a max prop with adjustable pitch, and the previous
> > > owner
> > > > (or me the last time I serviced it) set the pitch too low.
> > > >
> > > > Good luck. Let us know if you figure it out.
> > > >
> > > > Jeff Smith, #121
> > > >
> > > >
> > > >
> > > > On Fri, Jun 9, 2023 at 9:54 AM Dave Hupe via C320-list <
> > > > c320-list at lists.catalina320.com> wrote:
> > > >
> > > > > Looks based on your photos like some minor coolant leak around the
> > > > > "radiator cap" neck on the heat exchanger tank. The cap looks
> > > > > original/rusty. So, wouldn’t hurt to replace it (7psi is what is
> > > spec'd).
> > > > > However, without seeing a trail of coolant leakage there, I am not
> > sure
> > > > > that is your problem.
> > > > > I have heard about blockage in the exhaust elbow causing
> overheating.
> > > Any
> > > > > consideration of that?  I replaced my entire heat exchanger tank
> > > because
> > > > > the "radiator cap" neck on the tank had a piece cracked off where
> the
> > > cap
> > > > > should seal.  I had to remove my exhaust elbow attached to the tank
> > and
> > > > > remount it on the new tank.  I carefully inspected my elbow and it
> > was
> > > > very
> > > > > clean and seemed fine to reuse.  My boat has always been in
> > > > freshwater.  I
> > > > > don't see on the hull roster or your posts where you are located
> > > > > (saltwater??). That can make a significant difference related to
> > items
> > > > like
> > > > > this.
> > > > > Dave Hupe
> > > > > 1994 C320 #32
> > > > >
> > > > > Sent from Yahoo Mail on Android
> > > > >
> > > > >  On Fri, Jun 9, 2023 at 1:42 AM, Paul Hetherington via C320-list<
> > > > > c320-list at lists.catalina320.com> wrote:  So still trying various
> > > > > suggestions here and have ordered a fresh water
> > > > > pump.  But we put a clear hose on the fresh water loop today and
> it's
> > > > very
> > > > > obviously circulating water.
> > > > >
> > > > > We thought we had maybe fixed the overheating after really running
> at
> > > > high
> > > > > revs the other day for testing of the prop (dislodged something?)
> so
> > > did
> > > > > some measurements/testing.  Unfortunately the temp climbed to 200
> > after
> > > > > about 30 minutes at 2700.  It dropped back down to 180 after 20 min
> > at
> > > > > 2000, and then climbed back to 185 after 30 minutes at 2500.  Not
> > sure
> > > if
> > > > > it had plateaued because we had to come in.  But clearly still
> have a
> > > > > problem.
> > > > >
> > > > > Any chance a small leak in the rad cap could cause this?  Here are
> > some
> > > > > pics.  We can't see  a leak, or water coming out but it looks
> > corroded
> > > > and
> > > > > we are trying anything at this point.  What is the best way to test
> > > this
> > > > > out?
> > > > >
> > > > > Pics here:  https://photos.app.goo.gl/E83NV9cPXe6JFXXZ8
> > > > >
> > > > > We are getting pretty discouraged at this point.  The boat is
> usable,
> > > but
> > > > > the month long journey we have planned for this summer is going to
> be
> > > > tough
> > > > > with 4 knots through the water.  Especially because some of the
> > passes
> > > up
> > > > > here can be 8 knots (really have to time it!).
> > > > >
> > > > > Thanks, Paul.
> > > > >
> > > > > ----------------------------------------------------------------
> > > > > Paul Hetherington
> > > > > Seasun, 1994, Hull #155
> > > > >
> > > > >
> > > > > On Mon, May 29, 2023 at 7:27 PM Paul Hetherington <paul at heth.ca>
> > > wrote:
> > > > >
> > > > > > Some good thoughts here. Thanks to all.  Will be trying a few
> > things.
> > > > > >
> > > > > > One thing that has come up, how would we best confirm the non-raw
> > (so
> > > > > > fresh) water pump is working well?  There is no impeller that I
> > know
> > > > of,
> > > > > so
> > > > > > not entirely sure how the water is 'pushed' around the circuit.
> It
> > > > would
> > > > > > stand to reason that if this water isn't moving well then the
> > cooling
> > > > > > transfer won't be efficient and the temp would rise.  I'm just
> not
> > > sure
> > > > > how
> > > > > > to best test this.
> > > > > >
> > > > > > Cheers.
> > > > > >
> > > > > > ----------------------------------------------------------------
> > > > > > Paul Hetherington
> > > > > > Hull 155, 1994 Seasun.
> > > > > >
> > > > > >
> > > > > > On Mon, May 29, 2023 at 1:08 PM Dan Winsor via C320-list <
> > > > > > c320-list at lists.catalina320.com> wrote:
> > > > > >
> > > > > >> Here's my two cents worth...
> > > > > >> If the engine can't transfer its heat to the raw water then the
> > raw
> > > > > water
> > > > > >> would be cold when it enters the exhaust elbow. If that's the
> case
> > > > then
> > > > > >> swap out your new water pump. I don't believe in coincidences
> like
> > > > that.
> > > > > >> Dan Winsor
> > > > > >> Lucky Devil #109
> > > > > >>
> > > > > >> On Mon, May 29, 2023, 15:41 P.F. Ross via C320-list <
> > > > > >> c320-list at lists.catalina320.com> wrote:
> > > > > >>
> > > > > >> > Paul,
> > > > > >> >
> > > > > >> > Your experience sounds very much like mine.  I run at 190 at
> > 2700
> > > > rpm
> > > > > >> > cruise (I have an Autoprop) and have done all the things you
> > have,
> > > > > >> except
> > > > > >> > for doing the temp testing with a non contact thermometer.  It
> > has
> > > > > been
> > > > > >> > this way for many years and over those same many years
> replacing
> > > the
> > > > > >> temp
> > > > > >> > sender has been on my list.  I figure it is the only thing I
> > have
> > > > not
> > > > > >> done.
> > > > > >> >
> > > > > >> > I watch the temp gauge like a hawk, but it has always held
> > steady
> > > at
> > > > > 190
> > > > > >> > except for once when I sucked a plastic bag into the raw water
> > > > intake.
> > > > > >> So
> > > > > >> > at least I know my temp gauge moves!
> > > > > >> >
> > > > > >> > Frank Ross
> > > > > >> > Beta Wave #206
> > > > > >> > Naples, FL  34102
> > > > > >> >
> > > > > >> > On Mon, May 29, 2023 at 2:26 PM Dave Hupe via C320-list <
> > > > > >> > c320-list at lists.catalina320.com> wrote:
> > > > > >> >
> > > > > >> > >
> > > > > >> > >
> https://www.parts4engines.com/perkins-perama-m30-water-pump/
> > > > > >> > > This would be the engine water pump.
> > > > > >> > > Dave Hupe
> > > > > >> > > 1994 C320 #32
> > > > > >> > >
> > > > > >> > > Sent from Yahoo Mail on Android
> > > > > >> > >
> > > > > >> > >  On Mon, May 29, 2023 at 3:02 PM, Paul Hetherington via
> > > C320-list<
> > > > > >> > > c320-list at lists.catalina320.com> wrote:  Yes our M30 is
> > running
> > > > > hot.
> > > > > >> > > 2500 rpm = 190, much over that and it pushes
> > > > > >> > > over 200.  Haven't had the guts to push it right into
> > triggering
> > > > the
> > > > > >> > > overheating alarm (203? - not totally sure it's
> functioning).
> > > But
> > > > > we
> > > > > >> > used
> > > > > >> > > to be able to run at 2700 with no overheating (185-190) and
> > now
> > > it
> > > > > >> heats
> > > > > >> > up
> > > > > >> > > very quickly.
> > > > > >> > >
> > > > > >> > > I am pretty sure I have read all the previous threads and
> > tried
> > > > many
> > > > > >> of
> > > > > >> > the
> > > > > >> > > suggestions but we are still stuck, so posting our detailed
> > > > approach
> > > > > >> is
> > > > > >> > > only to clarify it to myself, but hoping to get some
> > > insight/ideas
> > > > > >> from
> > > > > >> > > your experience.
> > > > > >> > >
> > > > > >> > > Here is what we have tried:
> > > > > >> > >
> > > > > >> > >  - Checked the raw water intake and all was clear.
> > > > > >> > >  - Removed hose between seacock and water filter and
> confirmed
> > > > good
> > > > > >> > water
> > > > > >> > >  intake flow through seacock
> > > > > >> > >  - Diver conformed no obstruction from below at the entrance
> > of
> > > > the
> > > > > >> > >  seakcock
> > > > > >> > >  - Topped up the coolant
> > > > > >> > >  - Replaced the impeller
> > > > > >> > >  - Replaced the thermostat (Even though the old thermostat
> was
> > > > > >> working
> > > > > >> > >  fine when I tested both of them in boiling water)
> > > > > >> > >  - Took out the heat changer and cleaned in a bath of
> muriatic
> > > > acid.
> > > > > >> It
> > > > > >> > >  was then very clear.  It was not that clogged up to begin
> > with
> > > > > >> though
> > > > > >> > >  - Replaced the exhaust elbow (after ordering one with
> current
> > > > > >> > downstream
> > > > > >> > >  tube diameter)
> > > > > >> > >  - Replaced the raw water hoses between the intake seacock,
> > > > between
> > > > > >> the
> > > > > >> > >  raw water filter and the water pump with new reinforced
> hoses
> > > to
> > > > > >> make
> > > > > >> > > sure
> > > > > >> > >  that they are not collapsing
> > > > > >> > >  - Kept testing the engine in forward gear, tied to the
> dock,
> > > and
> > > > > >> > >  measured temperature with heat gun all over engine block,
> to
> > > > > >> confirm it
> > > > > >> > >  wasn't a gauge issue.
> > > > > >> > >  - When engine was ran at 2500 rpm or higher, measuring
> > > > temperatures
> > > > > >> > >  between 195 and 200 around the coolant pump
> > > > > >> > >  - Always seemed to have good water flow coming out of the
> > boat
> > > > > >> > >
> > > > > >> > > Right around the time we started to have overheating issues
> > two
> > > > > other
> > > > > >> > > events happened that may or may not be related.  We switch
> > from
> > > a
> > > > > >> tired
> > > > > >> > and
> > > > > >> > > chipped 2 blade prop to a 3 blade Campbell Sailer prop AND
> the
> > > > water
> > > > > >> pump
> > > > > >> > > was leaking so we replaced it with this one from
> > parts4engines:
> > > > > >> > >
> > > https://www.parts4engines.com/perkins-perama-m30-raw-water-pump/
> > > > > >> > >
> > > > > >> > > Any help is appreciated.
> > > > > >> > >
> > > > > >> > > Cheers.
> > > > > >> > >
> > > > > >> > >
> > ----------------------------------------------------------------
> > > > > >> > > Paul Hetherington
> > > > > >> > > Hull 155, 1994 C320
> > > > > >> > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > > >
> > > > >
> > > > >
> > > >
> > >
> >
> >
>