Pearson Yachts Forum

Pearson Boats - Common Systems => Engine and Drive Train => Topic started by: Coppifan on October 10, 2011, 01:44:40 PM

Title: Engine overheating?
Post by: Coppifan on October 10, 2011, 01:44:40 PM
My 1980 MD 11 Volvo Penta engine guage yesterday showed that it was over heating. Right at the beginning of the red... I checked everything I could, but found no reason why it should be. Water flow out the stern was normal. If I increased the throttle, it actually went down a little. I'm thinking it's the guage, not the engine. Thoughts appreciated.
Title: Re: Engine overheating?
Post by: Dolce_Vita on October 10, 2011, 04:27:26 PM
With all the debris in the Chesapeake since Irene and Lee, you might have sucked something into your cooling water intake.

This happened to one of my dockmates recently.

It doesn't take much of an obstruction to cause overheating,  especially if you have freshwater cooling. You might not be able to eyeball the differance.

The places to check are the exterior strainer/grate, the inline interior strainer, and the inside of the end caps on the heat exchanger.  A different friend had a marginal overheating problem that he fought with for a year until he discovered a fragment of a paper towel stuck in one end of the heat exchanger!
Title: Re: Engine overheating?
Post by: Libations Too on November 23, 2011, 11:34:42 AM
Hi Bill,

Were you able to resolve your overheating problem?

I can second Dolce Vita's comment about checking for obstructions. I had an overheating problem one time on my MD11 that turned out to be some growth on the hull that simply obstructed the intake thru-hull. The engine ran normally at idle but as soon as I put it in gear and increased engine speed it overheated. I removed the hose at the seacock and pushed a small rubber hose back through the seacock and thru-hull. That was followed by a hull cleaning and careful inspection by my diver. All operated normally after that.


Title: Re: Engine overheating?
Post by: nickzchef on November 24, 2011, 09:10:46 AM
This happened to me once.  It was a combination of a bad Thermostat, and a clogged pin hole on the exhaust vented loop, usually located in the port sail locker forward bulkhead, which restricted water flow a bit.  Good luck!
Title: Re: Engine overheating?
Post by: Rusty Pelican on December 07, 2011, 02:12:11 PM
Most P323 w/ Volvo MD11c have raw water cooling. The block cooling ports were undersized
If all other possible causes prove negative, your looking at
an exhaust manifold, as well as a gasket kit.
Also remove the pet-cocks clean the ports, and reassemble
This should do the trick