A "low coolant" message continues to flash and I just filled it up. its a 98 with 102k. it does not run hot, and there seems to be nothing under the car when i move it. what gives? your help is needed. and it does not run hot, and the tem says about 212-214 degrees

 

You could have a bad sensor with the age of the car. Have you checked all possible creases and pockets of the engine block where leaks could be sitting and just drying up later on because of the engine heat? Check the heads for coolant leaks, all the lines, the radiator.

 

Do you continue to fill it up time after time?
If not it could just be a bad sensor. On some other GM vechiles the sensor was in the tank and when the coolant level fell to low the sensor would move down and break the connection (two sides of the sensor overlapping when the coolant is full) which causes the sensor to show the low coolant warning. You could take a magnet and move along the radiator to reset it. Not sure if the same system is used in the vette though. I hope I explained the sensor clearly, kind of hard to put in words.

If you keep filling up and it goes low again, then I would do a pressure test. You can rent/borrow the tool for free from your local AutoZone. You can also check the bottom of the waterpump for corrosion that would indicate a leak as well as the passenger floorboard for a heater core leak.

 

how much coolant does it actually hold, and is ther a process for adding it?

 

File In Section: 06 - Engine/Propulsion System

Bulletin No.: 99-06-02-016

Date: October, 1999

TECHNICAL

Subject:
Engine Low Coolant Light Comes On At Start-Up
(Inspect for 2nd Design Radiator Surge Tank and Replace/Reposition)

Models:
1997-1999 Chevrolet Corvette
1997 Models Built Prior to VIN Breakpoint V5104277

This bulletin is being revised to add the 1999 model year and change the part number identification procedure. Please discard Corporate Bulletin Number 83-62-11 (Section 6 - Engine)

Condition
Some customers may comment that the "low coolant" light comes on at start-up.

Cause
This condition may be caused due to the low coolant sensor being mounted in the rear of the radiator surge tank. When the vehicle is parked with the front lower than the rear, the coolant settles in the front half of the surge tank and with the switch in the rear of the tank, the switch float may be low enough to trigger the light. The "low coolant" light may come on if:

- The vehicle is a 1997 model, built before VIN V5104277, with the old design radiator surge tank.

- The radiator surge tank is improperly installed in the vehicle.

- The coolant level in the vehicle coolant system is low.

- The float in the tank is sticking.

- The coolant level switch connector is improperly connected.

Correction

Caution :With a pressurized cooling system, the coolant temperature in the surge tank can be considerably higher than the boiling point Of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boll instantaneously with explosive force. This will cause the solution to spew out over the engine, fenders, and the person removing the cap. Serious bodily injury may result.

1. For 1997 vehicles built prior to VIN breakpoint V5104277, replace the radiator surge tank and inspect for an out of position wiring harness under the tank. To repair the harness, position the harness downward and secure with a tie strap. To determine if the surge tank is of the first or second design, inspect the low coolant switch cavity in the surge tank. If the surge tank cavity extends 16 mm (5/8 in) below the bottom of the surge tank, the tank is of a second design tank. If the cavity is less than 15 mm (19/32 in) replace the tank with P/N 10405218.
2. For all vehicles, check the level of the tank by viewing the lower mount on the tank. Less than 2 mm (0.08 in) (# 1) of the mounting slot should be visible above the attaching nut. If the gap is greater than 2 mm (0.08 in), loosen the surge tank and hold in a downward position to achieve less than a 2 mm (0.08 in) gap above the attaching nut. Tighten the bottom nut first, then both top nuts.

Tighten

Tighten the nuts to 10 N-m (89 lb in).

3. Verify coolant level in surge tank:

- If engine coolant is hot, above 83°C (180°F), fill the coolant surge tank 12 mm (1/2 in) above the cold indicator mark.

- If the engine coolant is at ambient room temperature, fill to the top of the cold indicator mark.

Parts Information

All parts in the GM Parts System since January 1997, and all parts used to manufacture vehicles since January 1997, are of the second design. If a vehicle is one of the 1997 vehicles prior to the serial number breakpoint, you may have to replace the radiator surge tank as described in Step 1, above.

P/N Description

10405218 Tank Assembly, Radiator Surge

Parts are currently available from GMSPO.

 

Pull your plugs, look for an exceptionally clean one.

 

bhard,

Your description of your problem is ambiguous.

You say you added coolant, and continue to get the LOW warning. Then you ask if there is a process for adding it ....

1) Add a 50/50 mix of Dexcool and water to the coolant reservoir until the reservoir reads FULL. Read your owner's manual if you don't know how to do this.

2) If the LOW COOLANT warning is coming on with the coolant resrvoir at the FULL mark, the sensor in the reservoir needs replacing.

3) If the coolant level drops, and continues to drop, after you have filled the reservoir, then you have a coolant leak. It may be internal to the engine (head gasket, for example) in which case you won't see coolant on the ground. The cooling system needs to be pressure tested to locate a cooling leak that is not readily apparent.

HTH

 

If you get to number 3 above - look at the oil -- does it look like chocolate milk? If so, that's where your coolant is going

It can also escape/evaporate through a radiator cap if it doesn't seal to the required PSI (15?) --- (although the C5 cap is a bit different than normal, so unsure about that....)

 

where will the PSI come from?

 

Do you mean where does the internal system pressure come from? Its from the coolant expanding due to heat.

 

If you are asking that kinda question, take your car to a mechanic and have them look at it. You clearly can't even follow (or respond to) the three steps I gave you above.

 

You may or may not have this problem, but I just thought I'd throw in my experience. I just had my water pump replaced this week.

I bought my 2000 coupe about two months ago. A couple of weeks after I bought it I noticed the coolant was low, so I filled it up. I would occasionally get a slight wiff of coolant if the wind was blowing just right. About a month later, the same thing, filled the overflow tank back up. Still no leaks noticable on the ground, nor did it run hot.

Well finally after two months of having the car it's started leaking coolant in massive amounts. The pump was apparently leaking the whole time, but not enough do get on the ground. It was leaking out the weap hole down onto the AC belt.

 

Had a similar problem with my Tahoe.

My mechanic was busy with my other cars, and told me to buy a new radiator cap. Voila! No more problem.

 

Higher vapor pressure because the coolant is hotter and wants to boil, so it does until the pressure is high enough to stop it.

From experience, if the radiator cap is leaking, you can see where the water is running down from a channel on top of your resevoir. I'd do what Blk Z06 said, then if it's not the sensor, before parking the car, drive it for a min or two w/ the a/c off (fans should turn on at a higher temp) to exacerbate the problem, park it on a clean surface and look for coolant after it's been parked about 30 mins.

If coolant is still dropping and there is no puddle after multiple tries, pray you don't have a clean plug or chocolate-milk oil.