low coolant...really?
Thread Starter
Racer
Joined: Oct 2002
Posts: 269
Likes: 0
From: Bigues Spain BCN
low coolant...really?
In my 88, I am having the low coolant light coming on every now and then...
I keep checking the coolant and the level is always OK in the reservoir and in the radiator!, no leaks anywhere...
No overheating at all.
Is there any way to check the sensor?, where is it located?
I keep checking the coolant and the level is always OK in the reservoir and in the radiator!, no leaks anywhere...
No overheating at all.
Is there any way to check the sensor?, where is it located?
Racer
Joined: Nov 2002
Posts: 300
Likes: 0
From: Perth WA
Re: low coolant...really? (JordiZR1)
I have the same problem. The sensor is just a peice of metal which runs into the radiator and when there is enough water in the rad it earths the wire throught the coolant. I have checked mine by just earthing out the sensor wire and yhe light goes on and off like it should, but it still goes on and off. I haven't had time to solve this problem yet but when I do I will post the results. If you do too it will be a great help. I am suspecting the wiring or a relay but I haven't been able to find it on my manual wiring diagrams yet.
Good Luck
Good Luck
Thread Starter
Racer
Joined: Oct 2002
Posts: 269
Likes: 0
From: Bigues Spain BCN
Re: low coolant...really? (timallard)
Ok, If it works that way I suspect it could be a bad ground. I have been experiencing some other minor electrical problems lately (loss of data in the cluster, AC head going on/off at will, and failure to start the engine at first try, etc...) Now everything makes sense if I have a bad ground connection.
Where does the 88 ground the negative terminal, to the chassis, to the engine or both?
Where does the 88 ground the negative terminal, to the chassis, to the engine or both?
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: low coolant...really? (JordiZR1)
Start the car with the cooling system cold and the cap off. Let it run till the thermostat opens up. Have someone hold the RPM @ 2000 and you might see the coolant fall loewr into the radiator. Add enough to bring it up to the neck and put the cap back on. Then let the RPM back to idle.
Drifting
Joined: May 1999
Posts: 1,478
Likes: 3
From: Sacramento, CA Money can't buy happiness - but it's more comfortable to cry in a Corvette than a Yugo.
Re: low coolant...really? (JordiZR1)
JordiZR1,
I had the same problem on my 88. I put it off for a while until it went from intermittant to nearly full time. The coolant level was good so I suspected the sensor.
As mentioned by another, the sensor is located on the radiator just under the radiator cap and has one green wire attached to it. The sensor is held in by 2 palstic hooks that are a pat of the sensor housing. Carefully pry the 2 slim and fragile plastic clips away from the retaining ring edge of the radiator housing and the sensor should slide right out. On the back of the sensor the green wire connects with a blade type electrical connector. The wire will slip off pretty easy unless it is really cororded.
I cleaned the electrical blade that connects to the green wire with emery cloth (or very fine sand paper will work) and WD-40. Clean the sensor blades the same way. Reassemble and plug it back into the radiator. Very easy. Should take about 15-20 minutes tops.
I had the same problem on my 88. I put it off for a while until it went from intermittant to nearly full time. The coolant level was good so I suspected the sensor.
As mentioned by another, the sensor is located on the radiator just under the radiator cap and has one green wire attached to it. The sensor is held in by 2 palstic hooks that are a pat of the sensor housing. Carefully pry the 2 slim and fragile plastic clips away from the retaining ring edge of the radiator housing and the sensor should slide right out. On the back of the sensor the green wire connects with a blade type electrical connector. The wire will slip off pretty easy unless it is really cororded.
I cleaned the electrical blade that connects to the green wire with emery cloth (or very fine sand paper will work) and WD-40. Clean the sensor blades the same way. Reassemble and plug it back into the radiator. Very easy. Should take about 15-20 minutes tops.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: low coolant...really? (JordiZR1)
You have air in your cooling system and with the engine off and looking into the radiator filler, the coolant looks full. Perform Scorp's procedure AND fill the overflow bottle half way when you are done. You can race the engine by yourself by opening the throttle at the throttle cable end stop on the front of the MAF. With air in your cooling system, when the thermostat opens and the coolant starts flowing, the air moves out of the top of the block and the coolant level lowers and turns on the low coolant light.
Instructor
Joined: Jun 2003
Posts: 187
Likes: 0
From: Orange Park Fl
Re: low coolant...really? (Mike_88Z51)
Do you have to drain the coolant level below the sensor before you remove it?
I have the same problem - Low Coolant light comes on intermitantly while driving, Appears to be associated with decelleration from highway speeds. Had the coolant system flushed and pressure filled 3 weeks ago and still does the same thing.
I have the same problem - Low Coolant light comes on intermitantly while driving, Appears to be associated with decelleration from highway speeds. Had the coolant system flushed and pressure filled 3 weeks ago and still does the same thing.
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Racer
Joined: Nov 2002
Posts: 300
Likes: 0
From: Perth WA
Re: low coolant...really? (Kens86)
Do you have to drain the coolant level below the sensor before you remove it?
Pro
Joined: Apr 2003
Posts: 712
Likes: 0
From: Memphis TN
Re: low coolant...really? (DocToss)
Any pics of where the bleeder valve is on the thermostat housing in a 92? I think I see it but I sure don't want to unscrew something that does not need it. Is it on the passenger side of the housing? Thanks
Instructor
Joined: Sep 2002
Posts: 227
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From: Barnstable Mass
Re: low coolant...really? (JordiZR1)
Do what Scorp said. Ihad the same problem after installing new heads and it stopped after I added coolant with engine reving. I was surprised how much the level fell when I held the throttle open.
Thread Starter
Racer
Joined: Oct 2002
Posts: 269
Likes: 0
From: Bigues Spain BCN
Re: low coolant...really? (Five Window)
In fact I rebuilt the heads, but it was 3-4 months ago, and I have driven the car let`s say 300-400 miles without the light coming on... so ???
Pro
Joined: Apr 2003
Posts: 712
Likes: 0
From: Memphis TN
Re: low coolant...really? (JordiZR1)
I just pulled and cleaned my radiator.When I filled it back up with coolant, my low coolant light stays on and my temps are around the same (200-210), I know this is normal, but I was hoping to lower the temps. I have burped it twice by reving 1600- 2000 for several minutes, then recapping the radiator. I even bled the thermostat housing both cold and after warming up, but my low coolant light still is on. The levels are normal. How do I check the sensor, or what else do I need to do? Is there a reset procedure like I had to reset my outside temp sensor? Thanks
Race Director
Joined: Feb 2003
Posts: 11,397
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From: Rockledge Florida
St. Jude Donor '07 thru '14, '24
Re: low coolant...really? (JordiZR1)
I had the same problem, spend weeks trouble shooting turned out to be air
in the system. Check out Scorp508's post, it works.
in the system. Check out Scorp508's post, it works.
