fluctuating coolant temp

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  #1  
Old 01-24-2013, 04:04 AM
grasshopper645's Avatar
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Default fluctuating coolant temp

Got my z28 on the road today for the first time after buying it 4 months ago! Am loving it, but having this issue

The low coolant light comes on after a couple of minutes of driving and stays on. The coolant isn't actually low though.

The temp guage sits at the first quarter when cruising at 60mph on the highway, but when I start idling in heavy traffic, the guage moves up just above the middle, with the highest it going to between the middle and three quarters.

Does this sound abnormal? If so any idea what to check? I'm hoping an air lock...Could this cause the low coolant warning?
 
  #2  
Old 01-24-2013, 06:48 AM
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Low coolant sensor most likely. Common problem on these cars. When I did my water pump change, the low coolant light came on but eventually just went away so i ended up not replacing my sensor.
 
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Old 01-24-2013, 07:11 AM
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4th Gen LT1 F-body Tech Articles are you checking the coolant level in the coolant reservoir or the radiator? need to check level in the radiator. 4th Gen LT1 F-body Tech Articles if the coolant level in the radiator has been low you will need to bleed the air out of the system. https://camaroforums.com/forum/lt1-l...-system-66742/
 
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Old 01-24-2013, 09:04 AM
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It takes a small forever to bleed the air entirely from these cars. I had the same experience as Raider. I just kept bleeding it and rechecking the level in the radiator about every other day. Eventually the light went off. Even the slightest bit of air or bubble will trigger that light.
 
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Old 01-24-2013, 11:54 AM
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Those sensors are prone to fail too. But better to bleed out all the air first before replacing any thing.

As for the temp gauge moving while idling, completely normal for it to go above 1/2, but not normal if it gets into the red. When you're moving at 60 mph you're shoving air through the radiator that cools everything. But when you're stuck in traffic and moving slow, there's very little, if any airflow until the fans kick in.
 
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Old 01-24-2013, 04:46 PM
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let's address the problems


low coolant sensor- it's an idiot light and does not communicate with the ECU so just unplug it. I use my eyeballs to check the coolant level

temp rising when in traffic- not a problem unless it is happening while the cooling fans are running

with an unmodified tune, the fans do not engage until the engine is hot. I had mine tuned to engage at 200 degrees. THe cooling fans do engage when the air conditioning is on
 
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Old 01-26-2013, 04:33 PM
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Thanks for your replies. Coolant in both radiator and the overflow are at the proper levels, low coolant light still on.

I just wanted to check about the coolant temp, im just not used to the guage moving around a little bit, in all the other cars ive driven the guage just sits in the middle and never moves.

Ill unplug the sensor for now, but might replace it at some stage.
 
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Old 01-27-2013, 01:43 AM
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I pulled the battery out and there is a puddle of coolant where the metal pipe goes down into what i assume is the resivior. Could this be triggering the warning light? Is this a big job to fix?

 
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Last edited by grasshopper645; 01-27-2013 at 02:35 AM.
  #9  
Old 01-27-2013, 06:06 AM
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if you have a hole in the pipe then it will suck air into the radiator when cooling off.
 
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Old 01-27-2013, 09:12 AM
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Originally Posted by craby
if you have a hole in the pipe then it will suck air into the radiator when cooling off.

^^ Exactly....filling the radiator with air instead of sucking coolant back into it.....
 


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