I hear water rushing through heater coil when cold and the fan is off. There are no leaks in antifreeze. I own a 2001 saturn sl-1. The water noise is pretty loud and happens in spurts.

Kinda sounds like you still have air in your cooling system. You will have to air bleed the system.

Your hearing lifter noise common in most cars in cold weather I have a 2001 sc1 same engine as yours here's how to get rid of that ticking sound go buy a quart of Lucas synthetic motor treatment change your oil and leave it 1 quart low add the Lucas synthetic oil stabilizer within 1 week you will not hear the noise agian reason your hearing the noise is there's no oil at the top of the engine on a cold start oil when cold is thicker hints why your noise in your engine what Lucas does is eliminate the dry start by the way my engine has 288,000 and does not use a drop of oil after you use this product you should use it every oil change you will see your car will thank you regards Chris

I had a Mazda 626 that was leaking water/antifreeze from behind the console/dash onto the floor. I never fixed the issue which was a small radiator/ heater coil that Mazda put in the worst place possible to try and fix under the dash. My guess would be that it is the heater coil/radiator which gives you your inside heat when the car is up to temperature, so you can turn on your fan and get heat. It could be something as simple as a loose hose clamp. I just let mine drip until I got rid of the car at 300,000 miles. If the water is sticky, then it's from your cooling system which is tied in with your cars heating system.

check heater coil, if it is going bad it will cause condensation buildup

Your water pump needs to be replaced. The bearing and seal is out on the water pump, which has caused a loss of coolant, and all the other symptoms.

If you are getting steam on the inner windshield or it smell like anti freeze inside the veh, Yes this is a bad heater core...Check down under the dash pull back the carpet and if its wet, than also bad heater core..
I hope this helps..

It can be a couple of things....first one is easy.

1. Low engine coolant level. Just remove the cap on the readiator (engine cold) and check the level of your antifreeze. If it is low, replentish it. This could be your problem.

2. Water pump has failed internally. Easy way to check, start your Benz, squeeze the radiator hose while it is running. Better to do this when the engine is cold. If you start to feel pressure in the upper hose, water pump may still be good. Should feel like rushing water going through the hose.

3. Thermostat. Could be a bad thermostat. If you run the heater and there is no heat but you have air flow...could be the thermostat. Bad air blend door actuator could do this also.

Hope this gives you a starting point!

Is the reservoir boiling over or is it just leaking? If it is just leaking you need to repair it with silicone sealer or a special PVC repair kit. If it is boing over you need to find out why. Is the fan running? Turn the A/C on and the fan should run continuously. If not then check the fuse. If the fuse is good check the fan itself by applying 12 volts directly to the fan motor. If the fan is good then replace the thermal relay. Now, if the fan is running as it should then your thermostat may be stuck closed, the radiator may be clogged internally or externally. Clean the radiator of all bugs and debris on the coils. Remove the radiator cap and start the engine with the radiator full. You will see the coolant start to move when the thermostat opens. if you do not, then the water pump may be defective but not likely unless it is leaking or making noise. It is probably a stuck thermostat. Drain the system with the heater set to hot. Flush the system with plenty of water from a garden hose. Replace the thermostat, and fill the system with a 50/50 mix of Antifreeze & Distilled water or buy it premixed. 1 Gallon antifreeze with 1 gallon distilled water will do unless you buy premix and it will take 2 gallons. Don not use tap water! Leave the cap off and start the engine and keep adding coolant until you see no more air escaping and you can add no more. If the system has bleeder valves use them to remove any trapped air. This should solve your overheating problem unless the worst case scenario has happened. A blown head gasket. If you see white smoke from the exhaust, a white foamy substance on the underside of the oil fill cap of dipstick, oil level is overfull, or miss on one or more cylinders, you may have a blown head gasket.

Most probably water pump,pass side or radiator on drivers side.also check cooling fan operation.

I would check if your vent to the outside is open. If it is I would check the vacum hose that controls the vent to open and close.