Temp gauge stays at low limit line - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 01-19-2014, 11:20 PM   #1
Jeeper
 
Cygnus's Avatar
 
Join Date: Jan 2014
Posts: 51
Temp gauge stays at low limit line

Search came up empty...
'99 TJ 4.5L Manual
Just replaced the temp sending unit thinking it was a failed sensor. Gauge reads at 100 when I start it, same after it warms up. Only time I see it move is as I start it, it moves up from the pin to 100F.

Happy time!
Brgds,
Cyggie

Cygnus is offline   Quote Quick Reply
Old 01-20-2014, 12:11 AM   #2
Jeeper
 
Snacktical's Avatar
 
Join Date: Sep 2012
Location: Washington State
Posts: 81
Did you buy an OEM part or something from a chain store?
I just changed my oil pressure sending unit with something off the internet to save a buck and found it's giving me a "dummy" reading.

__________________
"Rectum? Damn near killed him!"
Snacktical is offline   Quote Quick Reply
Old 01-20-2014, 12:47 AM   #3
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 29,137
Images: 2
My bet is something to do with the thermostat... Stuck open probably... especially if someone installed a "failsafe" thermostat which commonly hangs up in the open position. If you buy a new thermostat, make sure that it is a non-failsafe 195 degree model.
__________________
When you have a choice, buy American.

Jerry Bransford is offline   Quote Quick Reply
Old 01-20-2014, 07:20 AM   #4
Jeeper
 
Join Date: Apr 2013
Posts: 1,226
Thermostat stuck open or faulty gauge reading

How hot is the heater air?

You could get a non contact heat sensor from harbor freight and check temp that way,

Also are you getting a check engine light?

Too low coolant temp after running awhile always did a trouble cone on my mx5 until I replaced the thermostat
Digger84 is offline   Quote Quick Reply
Old 01-20-2014, 07:34 AM   #5
Jeeper
 
Join Date: May 2011
Posts: 2,021
I'd be willing to bet its a bad thermostat. If the heater air is luke warm and not the same temp as it usually is I'd replace the thermostat. You can test it with a pot of water, heating it and observing the temp it opens at, lots of info on the web about testing them. If you do replace the thermostat, get a factory original, I gambled twice over the years with thermostats I bought from PB or AAP and ended up doing the job twice. OEM thermostats only for me now.
demarpaint is offline   Quote Quick Reply
Old 01-21-2014, 11:38 PM   #6
Jeeper
 
Cygnus's Avatar
 
Join Date: Jan 2014
Posts: 51
The sending unit I purchased was a Borg/Warner, they rarely have failures in my experience. Probably like these guys are saying...
Now that I'm paying attention the heater DOES fluctuate a lot. I took a temp and it came out to about 98. Left side of the radiator about 188, right side (cool side) 85. I do believe you may be right about thermostat. I'll just move up my plan to service the cooling system. I have no idea when it was flushed and got new antifreeze, if it's anything like the rest of the truck...
Cygnus is offline   Quote Quick Reply
Old 01-22-2014, 07:08 AM   #7
Jeeper
 
Dncnbear1's Avatar
 
Join Date: Nov 2013
Location: Rocky point ny
Posts: 199
I was having same issue. Mine would go up to about 175 but no heat. I flushed heater core, block n put in new 195 thermostat n all is good now. Wouldn't say I could cook a roast on it like I've heard said but 100x better than it was
Dncnbear1 is offline   Quote Quick Reply
Old 01-22-2014, 10:32 AM   #8
Jeeper
 
freeskier's Avatar
 
Join Date: Mar 2011
Location: Longmont, CO
Posts: 2,356
If the gauge always reads 100 then it's probably a sender issue. If the thermostat was stuck open it would still work it's way up.
__________________
CU Boulder Aerospace Engineering
freeskier is offline   Quote Quick Reply
Old 01-22-2014, 10:50 AM   #9
Jeeper
 
Majnoon's Avatar
 
Join Date: Apr 2013
Location: Springfield Missouri
Posts: 2,204
Quote:
Originally Posted by freeskier View Post
If the gauge always reads 100 then it's probably a sender issue. If the thermostat was stuck open it would still work it's way up.
X 2 wouldn't start off at 100.
Majnoon is offline   Quote Quick Reply
Old 01-22-2014, 12:00 PM   #10
Commercial Member

WF Supporting Member
 
Big Sarge's Avatar
 
Join Date: Dec 2012
Location: Chester Virginia
Posts: 2,899
Quote:
Originally Posted by Cygnus View Post
Search came up empty...
'99 TJ 4.5L Manual
Just replaced the temp sending unit thinking it was a failed sensor. Gauge reads at 100 when I start it, same after it warms up. Only time I see it move is as I start it, it moves up from the pin to 100F.

Happy time!
Brgds,
Cyggie
My question is who made the 4.5L engine? That would help determine what we are even dealing with here.
__________________
click the link below to view my Custom Jeep shifters, pool ball shifters. College Teams now available
http://www.wranglerforum.com/f37/custom-camo-pool-ball-shifters-224388.html

_______
/l ,[____],
l---L -OlllllllO-
()_) ()_)--o-)_)
Big Sarge is offline   Quote Quick Reply
Old 01-22-2014, 12:10 PM   #11
Jeeper
 
Ditchdoc's Avatar
 
Join Date: Aug 2012
Location: Placentia
Posts: 2,537
Get the engine warmed up. Run the heater if the air is not as hot as it use to be. More than likely your thermostat is stuck open. If it's hot like it use to be then either wiring or gauge. These are just quick checks and no tools required.
__________________
Bender Bending Rodriguez is my role model.
Ditchdoc is offline   Quote Quick Reply
Old 01-29-2014, 02:40 PM   #12
Jeeper
 
Cygnus's Avatar
 
Join Date: Jan 2014
Posts: 51
Quote:
Originally Posted by Big Sarge View Post
My question is who made the 4.5L engine? That would help determine what we are even dealing with here.
Uh... Yeah, about that... look at my smilie at the bottom and you will understand why I accidently put 4.5 when I was thinking 2.5 :P
Cygnus is offline   Quote Quick Reply
Old 01-29-2014, 02:45 PM   #13
Jeeper
 
Cygnus's Avatar
 
Join Date: Jan 2014
Posts: 51
Okay, this weekend I did a full cooling system service, backflush with chemical, replace thermostat (yes I tested it at 195F) new 70% coolant mixed with distilled water. Still getting really weak heat, temp gauge is still at 100.
I've been paying a little more attention to my gauges, I occasionally notice the temp gauge jump somewhere in the middle and dive back down to 100. My oil pressure is also wonky, it will sometimes pin up to 80, other times run at 20-40.
Cygnus is offline   Quote Quick Reply
Old 01-31-2014, 10:47 AM   #14
Jeeper
 
Ditchdoc's Avatar
 
Join Date: Aug 2012
Location: Placentia
Posts: 2,537
Question for you. It's not like 14* outside when it does this right?
__________________
Bender Bending Rodriguez is my role model.
Ditchdoc is offline   Quote Quick Reply
Old 01-31-2014, 11:50 AM   #15
Jeeper
 
Join Date: Apr 2013
Posts: 1,226
Check instrument panel ground behind speaker and check instrument panel wiring plug make sure clean and tight
Digger84 is offline   Quote Quick Reply
Old 01-31-2014, 10:28 PM   #16
Jeeper
 
Cygnus's Avatar
 
Join Date: Jan 2014
Posts: 51
Quote:
Originally Posted by Ditchdoc View Post
Question for you. It's not like 14* outside when it does this right?
I'm in South Cali, never gets below 30*
__________________

Cyggie (I'm the one on the right)
Cygnus is offline   Quote Quick Reply
Old 01-31-2014, 10:31 PM   #17
Jeeper
 
Cygnus's Avatar
 
Join Date: Jan 2014
Posts: 51
Quote:
Originally Posted by Digger84 View Post
Check instrument panel ground behind speaker and check instrument panel wiring plug make sure clean and tight
First of all, thanks for taking the time to help.
Please elaborate:
Location of the ground, how to find.

I've done the plug & cluster pin clean with contact cleaner, is that what you mean? or is there something else I can do?
__________________

Cyggie (I'm the one on the right)
Cygnus is offline   Quote Quick Reply
Old 03-23-2014, 03:40 AM   #18
Jeeper
 
Cygnus's Avatar
 
Join Date: Jan 2014
Posts: 51
Out of frustration, I took the panel off again. 1/2 of a can of contact cleaner sprayed into the plugs behind the cluster and I got my temp gauge back. If at first you don't succeed, hit the butterfly with a sledge hammer.
I am however still seeing the high oil pressure, and I'm certain it's behaving correctly because I do see movement between approximately 75-80psi between idle and acceleration respectively. Do I need to change my sending unit or is there something else I should look at?
__________________

Cyggie (I'm the one on the right)
Cygnus is offline   Quote Quick Reply
Old 03-23-2014, 11:30 PM   #19
Jeeper
 
Majnoon's Avatar
 
Join Date: Apr 2013
Location: Springfield Missouri
Posts: 2,204
Sending units fail a lot. A clog somewhere can cause that but is very unlikely.
Majnoon is offline   Quote Quick Reply
Old 03-25-2014, 10:40 PM   #20
Jeeper
 
Cygnus's Avatar
 
Join Date: Jan 2014
Posts: 51
Problem was the instrument cluster plugs in the dash. Just needed to be hosed out thoroughly with electrical contact cleaner

__________________

Cyggie (I'm the one on the right)
Cygnus is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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:

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

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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 06:25 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC