General Maintenance & Repairs Leaks | Squeaks | Clunks | Rattles | Grinds
Sponsored by:
Sponsored by: CARiD

intermittent low coolant light?

Thread Tools
 
Search this Thread
 
Old Mar 29, 2009 | 08:32 PM
  #1  
josh1107's Avatar
Thread Starter
Launching!
 
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
Default intermittent low coolant light?

has anyone else had a intermittent low coolant light? the dip stick looks like enough is in it. once i stop and turn off the engine, when i turn it back on, its off. i put more coolant in, came on again. same thing. weird!

thanks
josh
Reply
Old Mar 29, 2009 | 10:01 PM
  #2  
LS6427's Avatar
Banned
iTrader: (2)
 
Joined: May 2008
Posts: 11,289
Likes: 13
From: South Florida
Default

Originally Posted by josh1107
has anyone else had a intermittent low coolant light? the dip stick looks like enough is in it. once i stop and turn off the engine, when i turn it back on, its off. i put more coolant in, came on again. same thing. weird!

thanks
josh
edit: oh, your the same guy from the other thread.

That dispstick has nothing to do with your coolant level.

The sensor reads radiator coolant level. You need to check your radiator coolant level. If its really low, top it off. If its full, you have a bad sensor, they go bad all the time and stay on or will come on about 3 minutes after you start it up every time you start it up. Its right below the radiator fill cap on the rear of the radiator, square thing.

Unplug it or replace it. Thats all you can do.
Reply
Old Mar 29, 2009 | 10:34 PM
  #3  
Silver98Formula79's Avatar
On The Tree
iTrader: (17)
 
Joined: Dec 2007
Posts: 113
Likes: 0
From: SETX
Default

I unplugged mine, I had the same problem...
Reply
Old Mar 29, 2009 | 11:14 PM
  #4  
Zerokube's Avatar
TECH Enthusiast
20 Year Member
iTrader: (4)
 
Joined: Jan 2004
Posts: 544
Likes: 0
From: Fort Lauderdale, FL
Default

im with silver on this one, unplugged it and low light went off.
Reply
Old Mar 29, 2009 | 11:21 PM
  #5  
wssix99's Avatar
Save the manuals!
15 Year Member
iTrader: (5)
 
Joined: Dec 2007
Posts: 12,967
Likes: 389
From: Chicago, IL
Default

Its probably a bad coolant sensor, which you DO want to fix. The sensor is there for a reason - to protect the aluminum block. Running low on coolant is a much more serious issue than if we had iron blocks. (Aluminum melts at half the temperature of Iron and can start warping when it gets to be above 350 degrees, which you can hit real quick with air in your system.)
Reply
Old Mar 30, 2009 | 05:56 AM
  #6  
josh1107's Avatar
Thread Starter
Launching!
 
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
Default

as long as the temp gage is reading normal the engine is ok right?
do i still fill the coolant in the same place?
Reply
Old Mar 30, 2009 | 10:06 AM
  #7  
LS6427's Avatar
Banned
iTrader: (2)
 
Joined: May 2008
Posts: 11,289
Likes: 13
From: South Florida
Default

Originally Posted by josh1107
as long as the temp gage is reading normal the engine is ok right?
do i still fill the coolant in the same place?
Yes. Your temp is read from a sensor in the driver side head.

and

Fill the coolant ONLY at the radiator cap on the radiator. That plastic over flow reservoir under the battery does nothing for your coolant level in the radiator.
Reply
Old Mar 30, 2009 | 07:27 PM
  #8  
tripps's Avatar
TECH Resident
iTrader: (7)
 
Joined: Apr 2005
Posts: 762
Likes: 0
From: Houston, TX
Default

I've had the same problem where the light has been on since the summer. Just went outside and unplugged and wrapped in electrical tape and zip-tied to a nearby wire. The temp gauge will save my aluminum block if anything goes wrong!
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Mar 30, 2009 | 08:34 PM
  #9  
josh1107's Avatar
Thread Starter
Launching!
 
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
Default

the sensor is 50 bucks, crazy!
Reply
Old Mar 30, 2009 | 08:48 PM
  #10  
wssix99's Avatar
Save the manuals!
15 Year Member
iTrader: (5)
 
Joined: Dec 2007
Posts: 12,967
Likes: 389
From: Chicago, IL
Default

Originally Posted by josh1107
the sensor is 50 bucks, crazy!
gmpartsdirect.com
Reply
Old Mar 30, 2009 | 08:54 PM
  #11  
wssix99's Avatar
Save the manuals!
15 Year Member
iTrader: (5)
 
Joined: Dec 2007
Posts: 12,967
Likes: 389
From: Chicago, IL
Default

Originally Posted by LS6427
Yes. Your temp is read from a sensor in the driver side head.

and

Fill the coolant ONLY at the radiator cap on the radiator. That plastic over flow reservoir under the battery does nothing for your coolant level in the radiator.
Does nothing for your the coolant level in the radiator if... you have a bad seal on the radiator cap.

As your coolant comes up to temparature, it pushes air out of the system and in to the overflow. As the coolant cools down, it sucks more fluid from the overflow. In order for this to work, you need a good seal at the cap. Once all of the air is out of the system, the coolant dipstick will give you an accurate reading.

As long as the overflow isn't dry and the system is sealed, adding fluid at the overflow is just as good as adding it directly to the radiator, except that adding at the overflow is a lot cleaner and its easy to do when the engine is warm.
Reply
Old Mar 30, 2009 | 09:22 PM
  #12  
josh1107's Avatar
Thread Starter
Launching!
 
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
Default

thanks, 36 bucks, nice. drove it all day today, no light....
Reply
Old Mar 31, 2009 | 05:29 PM
  #13  
99firehawk's Avatar
On The Tree
iTrader: (1)
 
Joined: Sep 2006
Posts: 104
Likes: 0
From: Canada
Default

Ive got the light on...
How do I know if I have a bad cap or bad sensor?
Reply
Old Mar 31, 2009 | 05:41 PM
  #14  
josh1107's Avatar
Thread Starter
Launching!
 
Joined: Dec 2005
Posts: 226
Likes: 0
From: citrus springs, fl
Default

i dont know, i checked my rad level, completely full. im guessing sensor
Reply
Old Mar 31, 2009 | 07:45 PM
  #15  
wssix99's Avatar
Save the manuals!
15 Year Member
iTrader: (5)
 
Joined: Dec 2007
Posts: 12,967
Likes: 389
From: Chicago, IL
Default

Originally Posted by 99firehawk
Ive got the light on...
How do I know if I have a bad cap or bad sensor?
Let the radiator cool, open the cap, and then look. If your sensor is covered by coolant, odds are 99% that the sensor is bad.

If your radiator cap is bad, you'll have a ton of air space just under the cap. If the coolant is up to the level of the cap and you don't have any leakage, then your seal is keeping a good siphon from the reservoir - and the cap should be fine.
Reply
Old May 30, 2009 | 07:30 PM
  #16  
jkichline's Avatar
TECH Regular
iTrader: (1)
 
Joined: Feb 2005
Posts: 416
Likes: 0
From: Bethlehem, PA
Default

Isn't it more likely that the sensor is just dirty and needs to be cleaned up? Cleaning the sensor helped in my other cars.

My T/A just started with the low coolant light. I'm on this website because I couldn't figure out where the thing is. I'm glad I read this thread because now I know. I'm going to try and clean it tomorrow morning. Anybody else have luck cleaning the sensor?
Reply
Old May 30, 2009 | 07:33 PM
  #17  
RCowan's Avatar
On The Tree
20 Year Member
Photogenic
iTrader: (25)
 
Joined: Nov 2001
Posts: 131
Likes: 0
From: NW Houston
Default

the sensor is on the back of the radiator, passenger side, next to the battery. Take the battery out of the car, drain just enough coolant so the level is below the sensor. There is a big metal wire clip that holds it in, that's it. Unplug the sensor and remove this clip and it slides straight out. Clean it for about 5 seconds under the garden hose and reinstall, fill radiator, replace battery. DONE!
Reply
Old May 31, 2009 | 05:54 PM
  #18  
wssix99's Avatar
Save the manuals!
15 Year Member
iTrader: (5)
 
Joined: Dec 2007
Posts: 12,967
Likes: 389
From: Chicago, IL
Default

Sometimes cleaning the sensor doesn't work. Mine was spotless. If they are dirty, that can foul the system, or sometimes they just plain go bad.
Reply
Old May 31, 2009 | 08:58 PM
  #19  
LS6427's Avatar
Banned
iTrader: (2)
 
Joined: May 2008
Posts: 11,289
Likes: 13
From: South Florida
Default

$19.58 at rockauto.com
Reply
Old May 31, 2009 | 09:04 PM
  #20  
jkichline's Avatar
TECH Regular
iTrader: (1)
 
Joined: Feb 2005
Posts: 416
Likes: 0
From: Bethlehem, PA
Default

Thanks guys! I tried cleaning it today. It was gunked up pretty bad. I cleaned it up. I had to use a screwdriver to get some of it out. Then I soaked it in electronics parts cleaner. After I got all the gook off, it looked pretty corroded but I put it back in. I thought I had success until I drove about 30 miles. Then the light came on and stayed on. I guess I'll just buy the part.
Reply



All times are GMT -5. The time now is 02:07 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE