[C320-list] Overheating Perkins Perama M30

[Glen]

On a similar year C320, we had overheat problems despite new impeller.  Found a huge amount of old impeller debris blocking the screen where the hose from the water pump attaches to the heat exchanger, pulled the hose, cleaned all the debris out of hose and screen, and overheat problem quit.  However if all your hoses were replaced, I'd assume they would have found and removed any debris from the heat exchanger screen.
 
One other possibility is the heat exchanger itself being clogged by corrosion over the years and not permitting adequate flow.
 
Hope that helps.
 
 

From: Donald Poole <dpoole15 at gmail.com>
To: C320-list at catalina320.com 
Sent: Monday, July 9, 2012 9:33 PM
Subject: [C320-list] Overheating Perkins Perama M30

First time out  in my recently purchased 1994 Catalina 320 (#0047). I had
checked all fluids ( Oil, Transmission, Cooling water) before starting the
engine. The coolant was low ( I had had most of  the engine hoses replaced
so I was not that surprised). After motoring about 10 minutes I noticed my
engine heating up. Rose to ~220F.  I shut it down, let it cool, then
checked the coolant level again. It was low. Started the engine and added
coolant with engine running assuming I had air in the system. Once full I
recapped and continued to run. Engine crept up to 200F at a 1500-1800RPM
idle. Oh yes, I did check the raw water/exhaust discharge first and it
appeared to be fine. A good bit of warm water exiting. I had also had the
raw water pump impeller replaced when they did the hoses. Looking for
suggestions as to what to check next.