Look here for help first!* Remove the coolant tank....use a garden hose to clean out the inside and remove any dirt or sludge....and possibly stop leak residue.
* Make sure there is a tube to the bottom of the tank.
* Check the hose to the rad for stoppages...make sure water will flow thru it OK.
* Replace the radiator cap if you are doubtful about it.
* Put it all back together using good clamps on the hose ends.
* Fill the coolant tank with 50/50 antifreeze mix.
* Drive the car a few times to allow the coolant level to stabilize....then when the car has sat overnight use a permanent marker to mark the coolant level EXACTLY on the side of the tank...you might want to adjust the level 1st...to be near where it should be.
* Now any time the car has sat overnight...you can at a glance see how much coolant has been lost. The reason for doing these things is that you can loose significant coolant through these various parts....especially if they are plugged or not sealing right.
Want to know WHY you are loosing the coolant? Well...good luck!
See below....
* Start the car after it has sat overnight...allowing it to warm up some(you might need to drive it a short way), but not up to the 1/2 point on the gauge...you are looking for the point where the coolant is hot and somewhat pressurized...but where it also will not evaporate where it leaks. You then stop the engine and LOOK for leaks using a good flashlight or drop light.
* Check the radiator...radiator hoses...heater hoses...around the thermostat area(gasket...the tube below it...sending units, etc)....along the headgasket seam....waterpump area (which is under the t-belt cover)....
* Tighten ALL radiator/heater hose clamps.
* Make sure your rad cap is good and has no debris on the rubber sealing surfaces.
* Try to remember IF you have any coolant smell inside the car.
Now you'll need to watch your coolant level for a few days...if it isn't going down much or at all...maybe you fixed something.
One test for a headgasket leak is to start the car up after sitting overnight...remove the rad cap and look for a stream of bubbles...this would indicate an exhaust into coolant leak....could try retorquing the head gasket bolts????
Sometimes a slight leak can be stopped using BarsLeak coolant stopleak....though it will leave an oily residue and mess in your coolant tank...I've never seen it cause real problems.
As far as using a block seal/head gasket sealer....I'm doubting these work...but they apparently sell a lot of it to people like myself who can't stand the thought of a headgasket repair. These usually contain water glass or sodium silicate...which is water soluable and which turns hard when exposed to air and where the water evaporates. Sometimes the prices are real close to absurd.
