Volvo MD11C Overheating - SailNet Community
LinkBack Thread Tools
post #1 of 3 Old 05-13-2004 Thread Starter
Junior Member
Join Date: May 2004
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Volvo MD11C Overheating

I have a Volvo MD11c that is raw water cooled and is overheating. Last season the temp would climb until it hit the red zone then move back well into the green zone(cooler). I have replaced the pump thermostat. A large volume of water exits the exhaust.
This season the temp climbs up to just near the red zone and stays there.
I think I need to remove the exhaust manifold and boil it out.
Am I on the right track? Also any advise on how best to remove it, any tricks and should I try to clean the water jacket on the block?
BTW: the boat is a Pearson 323
takwita is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
post #2 of 3 Old 05-13-2004
Senior Member
RichH's Avatar
Join Date: Jul 2000
Location: Pennsylvania
Posts: 3,689
Thanks: 26
Thanked 177 Times in 166 Posts
Rep Power: 17
Volvo MD11C Overheating

Whats the volumetric cooling water flow rate at X rpm? Dont have a manual or the data - call your distributor for the info.

Go to your manual and obtain the data, then run the engine at the spec. rpm until the thermostat fully opens, take a bucket and stop watch and catch the water coming from the exhaust. If the output is not up to spec. then you have a blockage somewhere: broken impeller vane jammed downstream in a hose, fouled thermostat, exhaust manifold starting to form ''platelette'' rust in the cooiing passages. Cast iron exhaust headers will form huge rust plateletts which break off from the interal cooling passage walls and block or partly block the flow - especially happens if you drain the water from engine during layup and let the cooling system "dry-out". If so, just poke a large stiff wire into the header to break up the flakes.... then check for pin holes into the ''gas side''.
You dont state if this is a fresh water (exhcanger) system or a raw water cooled engine. If the volumetric flow is within spec. then consder to ''pickle'' the engine to remove carbonate ''boiler'' scale by using an organic descaling agent such as Marsolve or RydLyme. If you use acid, you can dissolve the base metal of the engine as well as the scale.

When was the last time you changed the pump impeller(s)? Should be yearly!

RichH is offline  
Quote Quick Reply Share with Facebook
post #3 of 3 Old 05-16-2004
Junior Member
Join Date: May 2004
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Volvo MD11C Overheating

I have the same engine, but it was converted to fresh water cooling several years ago. Still, last summer it was overheating, but I could run it at about 1000 rpm for some time. To make a long story shorter, one of the (three) internal ports between the exhaust manifold and the block was clogged. So a thorough break-down and cleaning seems in order for you.
Good luck.
alpeaks is offline  
Quote Quick Reply Share with Facebook

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
Volvo Penta engine rondezvous Gear & Maintenance 1 09-24-2006 01:24 PM
anybody have info about volvo md1c obiec Gear & Maintenance 2 04-10-2003 11:02 AM
Fresh Water Cooling Volvo MD17C Nereus32 Gear & Maintenance 0 07-17-2002 01:19 PM
Volvo Folding vs Maxprop feathering uri General Discussion (sailing related) 1 06-27-2002 08:06 PM
Volvo intake valves for MD6A not avaiable from Volvo Larrys Pal Gear & Maintenance 5 03-27-2002 06:58 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome