86 Low Coolant Level
Thread Starter
Intermediate
Joined: Nov 2003
Posts: 31
Likes: 0
From: Houston TX
86 Low Coolant Level
I had my baby out on the 4th in heavy idling traffic with ac on. It overheated to 260 degrees. Cooled down once I got rolling. I checked the coolant level the following day and found the level was one gallon! low. I had no warning of a low coolant level. Mabe the sender is bad.
I replaced the leaking OEM water pump with a nice Edelbrock over a year ago.
Q1: Anyone know where the level switch is located, and how to replace?
Q2: I have no visible coolant leaks. Where do I start to look?
Jack
I replaced the leaking OEM water pump with a nice Edelbrock over a year ago.
Q1: Anyone know where the level switch is located, and how to replace?
Q2: I have no visible coolant leaks. Where do I start to look?
Jack
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
The switch (on an 87) is located on the passanger side of the radiator, kinda up high...easy to replace. Better check the engine oil first...make sure there's no coolant in the oil. 260 is HOT, you're supposed to shut it down when it reaches 260, according to my owners manual.
I'd be checking the area between the radiator and the condensor for debris....our C4s suck up all kinds of crap.
I'd be checking the area between the radiator and the condensor for debris....our C4s suck up all kinds of crap.
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
2. In your oil. What does the under side of the oil fill cap look like?
Last edited by 94z07fx3; Jul 8, 2008 at 11:56 AM.
Drifting
Joined: Feb 2003
Posts: 1,614
Likes: 163
From: Davis CA
About the sensor. It is on the passenger side of the radiator. You won't miss it. However, do have a new one in hand before you take the old one out. You will very likely snap off one or both arms on removal. My car did fine with only one functioning arm but the one good arm broke off the second time it was removed.
That said, you could have other problems as noted.
That said, you could have other problems as noted.
Thread Starter
Intermediate
Joined: Nov 2003
Posts: 31
Likes: 0
From: Houston TX
Thanks for the help guys. BTW my ride is an 86 1/2 with the aluminum heads.
I checked my oil and oil cap. Both are pristine. The engine runs fine with no sign of a blown head gasket, thank God!
I found my low coolant level sensor located about 6" below the rediator pressure cap on the passenger side. I suspect that my coolant level may not have fallen below that level as the radiator took a 1/2 gallon of coolant and the surge tank took the other half that I added.
My shop manual recommends checking the coolant level in the surge tank every time you open the hood. That's good advice, that I failed to heed.
My dash display flashed red briefly when the temperture reached 260. As soon as I started rolling the temperture rapidly cooled to the normal 180 with outside air at 100.
Q3: My AC doesn't seem to be putting out sufficient cooling. I've never had it serviced. The car has only 40K miles. Shop manual calls for R12 refrigerant Man, I'd hate to go thru that nasty upgrade. Did that in my Suburban and the cooling sucked due to lower efficiency.
Jack
I checked my oil and oil cap. Both are pristine. The engine runs fine with no sign of a blown head gasket, thank God!
I found my low coolant level sensor located about 6" below the rediator pressure cap on the passenger side. I suspect that my coolant level may not have fallen below that level as the radiator took a 1/2 gallon of coolant and the surge tank took the other half that I added.
My shop manual recommends checking the coolant level in the surge tank every time you open the hood. That's good advice, that I failed to heed.
My dash display flashed red briefly when the temperture reached 260. As soon as I started rolling the temperture rapidly cooled to the normal 180 with outside air at 100.
Q3: My AC doesn't seem to be putting out sufficient cooling. I've never had it serviced. The car has only 40K miles. Shop manual calls for R12 refrigerant Man, I'd hate to go thru that nasty upgrade. Did that in my Suburban and the cooling sucked due to lower efficiency.
Jack
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
temp
I have an 86. I too was concerned that the low level coolant sensor was bad.
To my shock and amazement, the coolant sensor is a little blade of metal encased in a plastic shell.
No "sensor", no electric device, just a little piece of metal molded in a plastic shell.
Unless you have taken it out, don't touch it.
Here's what you need to know:
The water grounds the blade to the block because the water is conductive, and the transistor that controls the light needs the ground to shut off the flow of electricity to the light that says "low coolant".
When you lose that ground, the transistor turns on the power to the light, and you know you need antifreeze.
If you don't get the low coolant light, I suggest that you clean the grounds on the head at the back of the engine, and clean the other end on the frame.
If you still do not get a low coolant light, I would suggest that you check the light bulb on the driver info panel, the previous owner might have driven years with that on and burned out the bulb.
or the bulb socket might have some anomaly.
To my shock and amazement, the coolant sensor is a little blade of metal encased in a plastic shell.
No "sensor", no electric device, just a little piece of metal molded in a plastic shell.
Unless you have taken it out, don't touch it.
Here's what you need to know:
The water grounds the blade to the block because the water is conductive, and the transistor that controls the light needs the ground to shut off the flow of electricity to the light that says "low coolant".
When you lose that ground, the transistor turns on the power to the light, and you know you need antifreeze.
If you don't get the low coolant light, I suggest that you clean the grounds on the head at the back of the engine, and clean the other end on the frame.
If you still do not get a low coolant light, I would suggest that you check the light bulb on the driver info panel, the previous owner might have driven years with that on and burned out the bulb.
or the bulb socket might have some anomaly.
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Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Your AC problem and your coolant leak may be the same problem. The heater core may be leaking into the AC box causing heat and coolant to be drawn into the box. The coolant will leak out the drain hose of the AC box and leave no trace of a leak. If you feel like your legs are unsually warm when the car is up temp with the AC "OFF" this may indicate the problem. You can bypass the hoses to see if the coolant leak stops and the AC performs better to be sure.
Good Luck!
Good Luck!
Drifting
Joined: Feb 2003
Posts: 1,614
Likes: 163
From: Davis CA
Typically, the first sign of a heater core leak is mist or clouds coming from the vents when running the AC. It's a neat effect until you realize that it probably is pretty darn harmful to breath.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
low coolant
check the hose that ges between the radiator and the overflow tank. if the hose is cracked, or the radiator cap seal is bad, it may not be sucking the coolant back into the radiator when the car cools off. If that happens, your car will again be low on coolant in a few days.
