Should I be able to see coolant moving? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Should I be able to see coolant moving?

ROCKRIDGE4WD Introduces a NEW Jeep Wrangler JK *led* tail Ruffstuff XJ Unirail Channel Reinforcement....Rugged Ridge Modular XHD Snorkel Now for both 3.8L and 3.6

Reply
Unread 05-07-2013, 09:49 PM   #1
Turtle71
Registered User
1983 CJ7 
 
Join Date: Dec 2010
Location: Jacksonville, Florida
Posts: 582
Should I be able to see coolant moving?

I noticed recently, that my temp gauge is creeping closer to the H than it ever has. That being said, this is probably the warmest weather I have driven it in since getting it on the road. Still feeling uncomfortable with the gauge reading I decided to change the thermostat. Ran it without radiator cap to burp it and did not see any "flow" when looking in the radiator. Temp gauge went really close to the H again so I decided to shut it off. Should I be seeing movement of the coolant?

__________________
My slow 83 CJ7 Build:[url]http://www.jeepforum.com/forum/f8/turtle71s-83-cj7-project-1136836/[/url]
Turtle71 is offline   Reply With Quote Quick reply to this message
Unread 05-07-2013, 09:58 PM   #2
Turtle71
Registered User
1983 CJ7 
 
Join Date: Dec 2010
Location: Jacksonville, Florida
Posts: 582
Here is a pic I took while stopped at a light. It does get slightly closer to the H than this pic shows. Like towards the end of the green line.
__________________
My slow 83 CJ7 Build:[url]http://www.jeepforum.com/forum/f8/turtle71s-83-cj7-project-1136836/[/url]
Turtle71 is offline   Reply With Quote Quick reply to this message
Unread 05-07-2013, 10:00 PM   #3
DYontheForum
Registered User
1981 CJ7 
 
Join Date: Oct 2012
Location: Jacksonville, IL
Posts: 265
Quote:
Originally Posted by Turtle71 View Post
Here is a pic I took while stopped at a light. It does get slightly closer to the H than this pic shows. Like towards the end of the green line.
You're almost outta gas!
DYontheForum is offline   Reply With Quote Quick reply to this message
Unread 05-07-2013, 10:24 PM   #4
Turtle71
Registered User
1983 CJ7 
 
Join Date: Dec 2010
Location: Jacksonville, Florida
Posts: 582
Thats the only gauge that doesnt work. I replaced the sending unit and float but it seems to be something else. Will have to track that down later though.

Anyone know if I should be seeing the coolant move when looking inside the radiator?
__________________
My slow 83 CJ7 Build:[url]http://www.jeepforum.com/forum/f8/turtle71s-83-cj7-project-1136836/[/url]
Turtle71 is offline   Reply With Quote Quick reply to this message
Unread 05-07-2013, 10:38 PM   #5
Jack61
Registered User
1981 CJ7 
 
Join Date: Feb 2012
Location: Page, Az
Posts: 441
If you still have the stock radiator with the cap in the middle then yes you should see some coolant movement once the thermostat starts to open.
__________________
It used to be, God bless America, it has become God help America
Jack61 is offline   Reply With Quote Quick reply to this message
Unread 05-07-2013, 10:49 PM   #6
VooDoo2
Registered User
1978 CJ7 
 
Join Date: Jun 2010
Location: Brisbane, Australia
Posts: 691
Replace the thermostat. Problem fixed.
VooDoo2 is offline   Reply With Quote Quick reply to this message
Unread 05-07-2013, 11:03 PM   #7
Turtle71
Registered User
1983 CJ7 
 
Join Date: Dec 2010
Location: Jacksonville, Florida
Posts: 582
Quote:
Originally Posted by Jack61
If you still have the stock radiator with the cap in the middle then yes you should see some coolant movement once the thermostat starts to open.
Mine has the cap on the drivers side. I believe the earlier models had it in the center.
__________________
My slow 83 CJ7 Build:[url]http://www.jeepforum.com/forum/f8/turtle71s-83-cj7-project-1136836/[/url]
Turtle71 is offline   Reply With Quote Quick reply to this message
Unread 05-07-2013, 11:04 PM   #8
Turtle71
Registered User
1983 CJ7 
 
Join Date: Dec 2010
Location: Jacksonville, Florida
Posts: 582
Quote:
Originally Posted by VooDoo2
Replace the thermostat. Problem fixed.
Not sure if you caught it in my first post but I just replaced the thermostat. Are you saying that the new one is bad?
__________________
My slow 83 CJ7 Build:[url]http://www.jeepforum.com/forum/f8/turtle71s-83-cj7-project-1136836/[/url]
Turtle71 is offline   Reply With Quote Quick reply to this message
Unread 05-08-2013, 01:19 AM   #9
VooDoo2
Registered User
1978 CJ7 
 
Join Date: Jun 2010
Location: Brisbane, Australia
Posts: 691
Missed it BUT did you test it in some hot water? Ive had one fail right out of the box before due to swarf/rust on the shaft. Ive also seen mechanic's put them in upside down and they wont open. Check for an airlock too. If all else fails remove the top pipe and make sure water is pumping out. Could be a blocked radiator, bad waterpump. In AU we generally wont run them as it doesnt get that cold here to need it.
VooDoo2 is offline   Reply With Quote Quick reply to this message
Unread 05-08-2013, 05:37 AM   #10
jeepdaddy2000
Registered User
1971 CJ5 
 
Join Date: Jan 2002
Location: Secret Squirrel hideout, afghanistan
Posts: 6,300
First thing you will want to do is check the actual coolant temp. You can do this either with a candy thermometer or with an IR gun.
If the coolant is too hot, then you need to look at the thermostat (bad or backwards), radiator (plugged or blocked) hoses (lower collapsed), bad radiator cap (won't hold pressure), or you may need a shroud.
If the temp is good, then you have a problem with the gauge or sending unit.
jeepdaddy2000 is offline   Reply With Quote Quick reply to this message
Unread 05-08-2013, 06:23 AM   #11
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert, CO
Posts: 10,977
It could also be tuning causing abnormally high combustion temps, like a lean mixture, or too little advance, etc....

If you haven't tried it, yet, connect manifold vac to your distributer. It will make the idle noticeably cooler.

Matt
Matt1981CJ7 is offline   Reply With Quote Quick reply to this message
Unread 05-08-2013, 08:36 AM   #12
Turtle71
Registered User
1983 CJ7 
 
Join Date: Dec 2010
Location: Jacksonville, Florida
Posts: 582
Thanks for the tips guys! I will test out your suggestions when I get a chance. Im also going to try and check the sending unit. Any additional ideas are appreciated so keep them coming.
__________________
My slow 83 CJ7 Build:[url]http://www.jeepforum.com/forum/f8/turtle71s-83-cj7-project-1136836/[/url]
Turtle71 is offline   Reply With Quote Quick reply to this message
Unread 05-08-2013, 10:19 AM   #13
Turtle71
Registered User
1983 CJ7 
 
Join Date: Dec 2010
Location: Jacksonville, Florida
Posts: 582
I havent been able to try the other things yet, but I did a quick test on the sending unit. I read on another thread to do this. I removed the wire going to the sending unit and touched it to a ground. This made the temp gauge peg out on the hot side. Does this mean the sending unit is bad, or is it functioning properly?
__________________
My slow 83 CJ7 Build:[url]http://www.jeepforum.com/forum/f8/turtle71s-83-cj7-project-1136836/[/url]
Turtle71 is offline   Reply With Quote Quick reply to this message
Unread 05-08-2013, 11:07 AM   #14
SLO_Ken
Registered User
1986 CJ7 
 
Join Date: Nov 2009
Location: California
Posts: 886
Quote:
Originally Posted by Turtle71 View Post
I havent been able to try the other things yet, but I did a quick test on the sending unit. I read on another thread to do this. I removed the wire going to the sending unit and touched it to a ground. This made the temp gauge peg out on the hot side. Does this mean the sending unit is bad, or is it functioning properly?
That tells you that the gauge is working properly. The sending unit is basically a variable resistor that changes its resistance based on temperature. Higher temp = lower resistance.

The following link is courtesy of John Strenk
http://home.roadrunner.com/~john.str...eQuickTest.htm
Check out tests 6 and 8.
SLO_Ken is online now   Reply With Quote Quick reply to this message
Unread 05-08-2013, 12:15 PM   #15
Turtle71
Registered User
1983 CJ7 
 
Join Date: Dec 2010
Location: Jacksonville, Florida
Posts: 582
Quote:
Originally Posted by SLO_Ken View Post
That tells you that the gauge is working properly. The sending unit is basically a variable resistor that changes its resistance based on temperature. Higher temp = lower resistance.

The following link is courtesy of John Strenk
http://home.roadrunner.com/~john.str...eQuickTest.htm
Check out tests 6 and 8.
Ah, gotcha. Thanks. I will have to get a hold of a voltmeter and test the sender next.

On a side note. I checked the previous thermostat that I changed out by heating it in a pot of water. It said 160 on the back so I assume its a 160 degree thermostat (I replaced with a 195). Sure enough it started opening right before the thermometer I was using got to 160.

So far that shows that the gauge and the thermostat are not causing this. Sending unit test is up next.
__________________
My slow 83 CJ7 Build:[url]http://www.jeepforum.com/forum/f8/turtle71s-83-cj7-project-1136836/[/url]
Turtle71 is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
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 e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

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.


Thread Tools






Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.