Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > Cooling System

Reply
 
Thread Tools Display Modes
  #1   IP: 68.193.75.76
Old 07-16-2007, 12:37 PM
omec omec is offline
New Member
 
Join Date: Jun 2006
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
Temperature gauge problems?

Is there any calibration adjustment on the old, 1970's vintage, Stewart Warner temperature gauges, and does anyone have the sending unit resistance values for the engine when cold and when at operating temperature?

Last season my temperature started running in the 170 F - 180 F degree range compared to 150 F - 160 F it had normally operated at. I checked the water flow and found that it was less than 1GPM at 1000 RPM. Installation of a valve in the thermostat bypass line to restrict the bypass flow got the temperature back to the 160 F - 170 F range.

This spring I decided to do some work on the cooling system which included an acid flush and mechanical scraping/rodding of the water jacket and head (first in 30 years), installation of a new jacket cover and inlet elbow, clean up and testing of the thermostat, and rebuild of the water pump including replacement of the "shoe". The shoe replacement more then doubled the water flow rate.

Apparently I did a good job, because this year I barely get the temperature gauge to register over 100 F. Just going by feel the engine temperature appears to be normal, and is certainly greater then 100 F. I checked out the temperature gauge and sending unit using Don Moyer's procedure and both units appear to be functional.
The gauge deflects slightly when power is applied, deflects to full scale when sensor wire is grounded, and the grounding is good.
The sending unit resistance is 980 ohms when the engine is stone cold and drops to 360 - 370 ohms after the engine has been cruising for 20 minutes at 1600 RPM (gauge shows 100 - 105 F). When I tap the gauge it briefly climbs to 140 - 150 F and then drops back to 100 F. About 15 minutes after stopping the engine the resistance measures at 330 ohms and the gauge indicates about 110 - 115 F.

I'm inclined to think that the gauge is bad but can't understand why it would stop functioning since it was Ok last year.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Temperature Gauge question Unregistered Cooling System 5 12-28-2010 11:46 AM
Overheating problems jdaly986 Cooling System 1 01-16-2008 10:32 AM
Nonfunctioning water temp gauge Unregistered Electrical 4 07-31-2005 11:46 PM
Temperature gauge not working Pythagoras Cooling System 0 07-28-2005 03:00 PM
installed alarms now engine temp not right eric 352 General Interest 8 01-21-2005 11:33 AM


All times are GMT -4. The time now is 01:13 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved