My low coolant light comes on every 2-3 days, I add coolant; but i never see any visible leaks.

More than likely the thermostat.

Try to reset the computer by removing the + battery cable from the battery. Wait at least 30 seconds and re-connect. Check to see if problem is corrected. If code remains replace the sensor in the coolant canister.

check you radiator fluid it is low

My guess would be a leaking intake or head gasket. Water in the cylinder(s) is shorting the spark plug until the temp comes up on the engine. The white smoke is the coolant being burnt off. check your coolant level it may be low.

Low coolant is detected by a sensor inside the plastic resevoir tank. These things lie, so if the resevoir has plenty of coolant, it's probably a dirty or faulty sensor. If you can't see coolant, add it directly to the resevoir. As for the A/C, you can purchase an A/C pressure gauge or complete check and fill kit at a parts store and follow the directions for using it. If the pressure reads low, with the car running and A/C on full blast, add refrigerant until you hear the compressor turn on. Check your gauge again. Once you have it to pressure, you should be good to go. If it never gets there, you have problems. If it gets there and stops working again days later, you have a slow leak.

Is it the LOW coolant light? Your car is equipped with a sensor on the expansion tank (radiator overflow). Right front fender. It's there for when the car heats up. As the engine heats up and the coolant expands it racks into the reservoir/overflow/expansion tank. When the engine cools, it sucks the coolant back in. If your car was low on coolant then there's a good possibility that as it cooled, it sucked the recently added fluid in. Check that it is full to the "cold full" level by looking at the tank before you start it for the day. If it's not, then the sensor is telling you to add coolant. If it is, then the sensor in the tank may be bad.

If you have no leaks you can see, you have a internal problem.
1) Head gasket not sealing off properly
2) Cracked head and/or block
Test
Purchase Block leak tester, for your coolant system and follow instruction. If it test reveals combusting gas in coolant. You will need to pull Cly. head for further testing.

some time when your water pump leak you can not see it. becase of the pully.look under the hood and if you see a line where the fluid is. that came from the pully. iam pretty shore your water pump is on its way out. sorry to tell you that good luck

It sounds like it is low on coolant. Coolant expands when it warms up so if it is just low enough to trip the switch when it is cold it will shut the light off when it warms up. You should be ok to just top it off but be sure that what you put in is compatible with what is in it. There must also be a leak somewhere in the system for you to have lost some to begin with. Depending on how many miles you have on the car it wouldn't hurt to have the cooling system flushed if it's never been done before. If you do get it flushed take it to the dealer to have it done. Explain to them the low coolant and have them check the system for leaks at the same time. Hope this helps

Have the car put on a rack and look for a white powder, this will be the residue left by the coolant leak, if you find nothing then pressure test the system and look for a pressure drop after a few minutes, if you have a loss of pressure then the system is leaking, if there is no sign of the leak then it is going inside one of the cylinders.