Scum Floating on Coolant - SailNet Community
 
LinkBack Thread Tools
post #1 of 5 Old 07-26-2010 Thread Starter
Senior Member
 
Join Date: Apr 2008
Posts: 850
Thanks: 32
Thanked 40 Times in 40 Posts
Rep Power: 12
 
Scum Floating on Coolant

Yesterday, when helping orient a friend to the the Volvo Penta 2003 diesel on his new-to-him boat, I noticed a layer (approximately 1/8") of tan scum atop the coolant in the expansion tank. There was no milkiness in the crankcase oil. Is the scum a cause for serious concern? What is it?
Hudsonian is online now  
Sponsored Links
Advertisement
 
post #2 of 5 Old 07-26-2010
Senior Member
 
kd3pc's Avatar
 
Join Date: Oct 2006
Location: Callao, VA
Posts: 1,529
Thanks: 0
Thanked 35 Times in 34 Posts
Rep Power: 13
 
likely oil in the coolant somewhere along the way...
kd3pc is offline  
post #3 of 5 Old 07-26-2010
██▓▓▒▒░░▒▒▓▓██
 
Join Date: Apr 2006
Posts: 13,640
Thanks: 11
Thanked 253 Times in 248 Posts
Rep Power: 15
   
Could be rust from not changing the coolant, could be oil contamination from a bad head gasket or other source. If it is oily, it will settle out and leave an oil stain if you scoop some out and let it set. That would be a source for concern since a blown head gasket can really ruin your day. If you catch it early, it only hurts your wallet.
hellosailor is offline  
 
post #4 of 5 Old 07-27-2010 Thread Starter
Senior Member
 
Join Date: Apr 2008
Posts: 850
Thanks: 32
Thanked 40 Times in 40 Posts
Rep Power: 12
 
Thanks for your replies. I, too, had speculated that it was a blown headgasket, cracked head, or warped head. Do any of you have any suggestions short of yanking the head to inspect the head gasket and sending the head out to by magnafluxed and checked for warpage?

Can this be nursed through until October or does it demand immediate response?
Hudsonian is online now  
post #5 of 5 Old 07-27-2010
██▓▓▒▒░░▒▒▓▓██
 
Join Date: Apr 2006
Posts: 13,640
Thanks: 11
Thanked 253 Times in 248 Posts
Rep Power: 15
   
You can nurse anything, depending on your luck and how you feel about gambling. Personally I feel that if there is any question for bad head gasket, you want to shut it down immediately and run diagnostics, so you don't damage the engine. You can ruin it, or get by for a long time, but you don't know without looking into it.

Any engine manual, any engine shop, can tell you which diagnostics and how to run them. There is dye to put in the coolant (to see if exhaust gas is getting into it) and the froth can be tested to see if it is oil or rust, and sometimes a radiator shop can lend you a pressure guage that replaces the radiator cap. if the pressure pulses as the engine runs--that's cylinder pressure being pushed into the cooling system.

The symptoms can vary because the gasket can leak in so many different ways. it can let cylinder pressure in/out of the other systems, or oil into the water, or vice versa, and sometimes just one problem happens, sometimes things all go kerflooie and they all get messed up.

All those diagnostics happen WITHOUT PULLING THE HEAD and any competent mechanic should be able to tell you what's up in less than an hour of his time.(Try to find a competent one, yeah.) So looking at the manuals (all engines are quite similar in this way) and DIY can be a good way to start.

If you do need to pull the head--that's not as bad as it might seem. A shop manual, a torque wrench, and some regular socket tools and you've got all you need. Do it slowly and carefully, per the manual, and a head gasket job is NOT a difficult or expensive job, in the grand scheme of things. If the gasket failed because the block or the head warped, it needs to be machined at a shop. If it failed because the block cracked, often the block can be welded rather than scrapped. You can't tell for sure until you get into it, but if it was just a gasket failure--that's a damned inconvenience, but not a budget buster.
hellosailor is offline  
Reply

Quick Reply
Message:
Options

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

Password:


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

Email Address:
OR

Log-in











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
Scum and Stain Removal from Hull engineer_sailor Gear & Maintenance 26 01-29-2015 12:46 PM
Scum in Fuel Tank sailak General Discussion (sailing related) 13 09-06-2014 11:01 AM
coolant loss troubleshooting recommendations? mrkeith Gear & Maintenance 38 05-08-2007 03:20 AM
Coolant Circulation Diagram Flow MHRitter Gear & Maintenance 0 10-31-2002 09:49 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