Newbie: Advice on Coolant Issue Appreciated

[cajuncorvette]

Thanks for this forum. Last month I purchased my first Vette - a 1988 C4 in great condition overall. The car runs and drives very well, except for the rattles in the doors -- but that's another subject. I drove the car home after I bought it-- over 400 miles -- all interstate miles. Since that time I have not driven it much.

Today, I made an appointment for restoration work (carpet, etc.) about 50 miles away. I fired up the Vette, and after driving about a mile or so, the Low Coolant light came on. It seemed to stay on for a few seconds, and then if I turned the car or moved erratically, it went off. I noted the coolant temp at 181F at this time. The outside temp was 70F.

Before today, I had not really driven the car since the day I bought it (the 400 mile trip)-- though I have started it and run it for awhile and back it in and out of the garage to clean, work on interior, etc. I have not noticed any leaks anywhere.

Today, after the low coolant light came on and off several times, I returned home (a mile) and checked the car's coolant reservoir -- it was half full with the engine running and warmed up. Coolant was fresh green. All hoses and belts appear new. I added water to the coolant reservoir -- almost filling it. The light went out, and I drove the hour and a half via Interstate and then city traffic to my appointment.

The car drove great. At times I used the A/C, but most of the time I did not. I noted the oil temp ranged from 198 to 210F and the coolant temp on the highway ranged from 181F to 194F in the city (I include this information because I don't know if this is average or not.) When I reached my appointment, I went inside for a few minutes. When I came out, there was coolant on the ground under my car.

I started the car and moved it to another parking spot, and I noticed a little running from the coolant recovery tank (which is where the previous spill was coming from as well).

Should I be concerned about this? Can anyone relieve my fears? I do know the coolant recovery top has a stick attached to it that is not connected to any other part of the tank except the top. I thought perhaps the coolant sensor is in the stick and is bad, but I don't want to make a mistake and hurt my car.
Could the sensor be bad? Did I just overfill the reservoir?

Thanks from a newbie. Any information you can share would be appreciated.
Happy Thanksgiving!

 

[compyelc4]

I would not be concerned. Coolant temps seem okay. Oil temp is comparable to mine too. You probably do not have a stock thermostat in there; actually reads a little lower than I am accustomed to with my '95. Anyway my guess is you have a fault in your coolant level sensor. One thing I'd do is get the coolant back to the proper level in the tank. That should correct your coolant recovery tank overflow.

 

[tonylong]

Once you have fixed any coolant leaks (do a pressure test, it's the only way), then you may have to "burp" the system to stop the Low Coolant from giving you false errors.
Remove the radiator cap. Fill the radiator with coolant. Run the engine until the coolant level rises and starts to overflow, with the engine still running, replace the cap.
You may have to repeat this several times when cold to burp all the air out of the system.
PS don't delay replacing the cap the moment it rises to overflow - it's HOTTT, use gloves too.

 

[ken mohr]

My low coolant light comes on occasionally. I cleaned the connector on the radiator with 600 sand paper and it has been fine since

 

[JAKE]

Ken and Tony nailed it.

Jake

 

[jgmotto]

Word of advice - if your low coolant light comes on and the coolant resevoir tank is not empty, alway remove the radiator cap and be sure the radiator is full to the top. If it is low, then you have a leak in the system and can't maintain a vacuum to pull coolant in from the resevoir. It could be as simple as a bad radiator cap or as serious as a bad head gasket or cracked head.