Low Coolant Indicator
Thread Starter
Safety Car
Joined: Jan 2003
Posts: 4,915
Likes: 6
From: Andover, KS
Low Coolant Indicator
My 87 keeps giving me a "Low Coolant" alarm on the message center. Checked the coolant level and all is well, but it's still there. Where is this sensor located? I tried tightening the overflow hose clamps with no improvement. Any ideas? Thanks for the help.
DD.
DD.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Low Coolant Indicator (C4Fanatic)
The sensor is just below the radiator cap.
Carefully remove the radiator cap with the engine warm, reach across and raise idle speed while watching coolant level (careful that it doesn't spurt out when you release the throttle).
If coolant drops below sensor level you have an air leak or a clog in the radiator cap or overflow resevoir; if level stays up to the sensor yet the light is On, replace the sensor.
[Modified by 65Z01, 2:42 AM 3/6/2003]
Carefully remove the radiator cap with the engine warm, reach across and raise idle speed while watching coolant level (careful that it doesn't spurt out when you release the throttle).
If coolant drops below sensor level you have an air leak or a clog in the radiator cap or overflow resevoir; if level stays up to the sensor yet the light is On, replace the sensor.
[Modified by 65Z01, 2:42 AM 3/6/2003]
Safety Car
Joined: Jun 1999
Posts: 4,441
Likes: 0
From: Columbia S.C.
Re: Low Coolant Indicator (65Z01)
I have the same problem, and I did what the others said...spent the $15.00 on a new sensor...well.....it still does it...so it isnt always the sensor...I haven't messed with it since.. :nonod:
Racer
Joined: Jul 2000
Posts: 421
Likes: 0
From: Glen Burnie Md
Re: Low Coolant Indicator (C4Fanatic)
C4Fanatic,
It probably has nothing to do with the sensor.
You may have some 'air' in your cooling system that needs to be 'purged'.
I'm the original owner of my '86 Vette, and I too had received this message numerous times over the years. I also checked my coolant hoses...changed them out...and continued to get the very same message as you.
About 9 years ago, I was listening in on some conversation a few mechanics were having, discussing this very same topic.
My ears perked-up, as they mentioned the 'fix', and that is to warm your engine to the point that you can remove your radiator cap (use a towel so as not to burn yourself)...have someone else sit in the driver's seat, and rev the engine to 2500 RPM. While holding this RPM, as you look into the neck of the radiator, you should notice your coolant has retreated futher into the radiator.
Have your coolant ready...and add it to full. Return to idle, and quickly cover the radiator opening with the cap. (Make sure your cap is OK. If the gasket inside shows any sign of 'age'...get a new one).
After about 5 minutes of idle, repeat the steps above, until you can not add any more coolant.
This should eliminate your 'add coolant' message.
It probably has nothing to do with the sensor.
You may have some 'air' in your cooling system that needs to be 'purged'.
I'm the original owner of my '86 Vette, and I too had received this message numerous times over the years. I also checked my coolant hoses...changed them out...and continued to get the very same message as you.
About 9 years ago, I was listening in on some conversation a few mechanics were having, discussing this very same topic.
My ears perked-up, as they mentioned the 'fix', and that is to warm your engine to the point that you can remove your radiator cap (use a towel so as not to burn yourself)...have someone else sit in the driver's seat, and rev the engine to 2500 RPM. While holding this RPM, as you look into the neck of the radiator, you should notice your coolant has retreated futher into the radiator.
Have your coolant ready...and add it to full. Return to idle, and quickly cover the radiator opening with the cap. (Make sure your cap is OK. If the gasket inside shows any sign of 'age'...get a new one).
After about 5 minutes of idle, repeat the steps above, until you can not add any more coolant.
This should eliminate your 'add coolant' message.
Le Mans Master
Joined: Dec 1999
Posts: 8,540
Likes: 1
From: And on the fifth day, subpoenas were served to Obama senior staff
Re: Low Coolant Indicator (merplastic87)
The post above is close, but dangerous.
Remove radiator cap when cool/cold. Start engine, and observe when it reaches operating temp and the thermostat opens (coolant seen flowing in rad. It will open and close a couple of times. When then thermostat opens add 50/50 AF/Water mix. When thermostat opens again (or stays open) have helper hold engine rpm at 1800 or high enough to drop the coolant level. Top up with coolant while at high rpm and install cap. Car can now go back to idle. Top up overflow container to full hot with coolant mix. Don't remove radiator cap.
You may need to "pack" the system again in a 100+ miles, but if it goes low after that, you have a leak.
Pete
Remove radiator cap when cool/cold. Start engine, and observe when it reaches operating temp and the thermostat opens (coolant seen flowing in rad. It will open and close a couple of times. When then thermostat opens add 50/50 AF/Water mix. When thermostat opens again (or stays open) have helper hold engine rpm at 1800 or high enough to drop the coolant level. Top up with coolant while at high rpm and install cap. Car can now go back to idle. Top up overflow container to full hot with coolant mix. Don't remove radiator cap.
You may need to "pack" the system again in a 100+ miles, but if it goes low after that, you have a leak.
Pete
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