Vehicle overheats. Fans okay, head gasket ok and

If you have already checked the radiator, fluids, thermostat, and thermo fans and your 1996 Hyundai Lantra Sportswagon is still overheating, there could be other issues causing the problem. Here are a few other things you can check:

1. Water pump: The water pump is responsible for circulating coolant through the engine and radiator. If the water pump is not functioning properly, it can cause the engine to overheat.
2. Head gasket: The head gasket seals the cylinder head to the engine block. If the head gasket is damaged or fails, it can allow coolant to leak into the engine, which can cause the engine to overheat.
3. Cylinder head: If the cylinder head is cracked or damaged, it can cause the engine to overheat.
4. Engine block: If the engine block is damaged or has a crack, it can cause the engine to overheat.
5. Clogged radiator: If the radiator is clogged with debris, it can prevent the coolant from flowing properly and cause the engine to overheat.

To determine the cause of the overheating problem, it will be necessary to perform a thorough inspection of the engine and related components. If you are unable to locate the source of the problem or are not comfortable attempting to fix it yourself, it is recommended to have the vehicle inspected by a professional mechanic.

What does scan data show ? Is the PCM - engine computer seeing coolant temp sensor input data ? Can the fans be truned on bi-directionally ? Do you know what that is ? Factory tech 2 scan tool can do that .
Your vehicle has two cooling fans and three relay's that the PCM energizes to control fan speed . Did you take your vehicle to a qualified repair shop ?
Relay Driven Dual Cooling Fan Diagnostics

Free wiring diagrams here http://www.bbbind.com/free-tsb

Did you check/replace the thermostat? Another possible cause may be hair line cracks in the head(s).

put a new water pump in. and check your coolant. if they are okay then you got a cracked head gasket, it aint cheap to fix.

Check for blown head gaskets. GM aluminum-head engines are VERY UNFORGIVING when it comes to being overheated. The heads usually warp, resulting in blown head gaskets and repeated overheating like you are describing. One of the main symptoms will be that you fill the cooling system and open the bleader screws to get the air out of the system. Then you start the engine and run it until the cooling fan comes on. When the fan comes on, place your hand behind the cooling fan and see if the air coming through the radiator is HOT. If it is blowing cool air, the coolant is not flowing through the radiator like it should. This is usually caused by high pressure in the cooling system due to combustion gasses getting in.

Either you have not bled the system, or possible fan not working, or head gasket problem. Solution

Step by Step
1. Check both hoses, do both have equal amount of pressure?
2. Run the vehicle where your gauge shows in the middle, shut the vehicle off then open the bleed valve near the heater line and wait till fluid comes out like a steady stream. Make sure you do not go low on coolant.
3. Turn on vehicle, turn on A/C high maximum blow check to make sure both fans are on. We are testing to make sure the fans at least work!.
4. After all this and you are still boiling over make sure your radiator cap is good if not then replace. Last but not least get a block tester to test for exhaust gases in the coolant. Rent one from autozone. $25.00 plus fluid which is about $8.00.

yes the head gaskets leaking on modern aluminum head engines is all to common. never overheat them, if they start to get hot shut it down and find out why, it can of course be the fans and plugged radiators or faulty thermostats but sounds like in your case the head gasket is leaking and combustion gas is entering the cooling system and this causes an overheat

Can you see the cooling fans come on? When the engine gets to 212 degrees the fans should come on. To test the fans, with the engine running turn the A/C on high, the fans should come on .
The system also has a 212 switch that screws into the intake manifold. This is what turns on the fans with no A/C.
I hope this helps you.

The three most likely thing's cause overheating are faulty thermostat,electric fan or clogged radiator. Only at has been overheat so much it boils dry that it will cause engine trouble. Most common problem's are blown cylinder head gasket or a cracked cylinder head.
mixing coolant and water depends on where the gasket has blown or head is cracked. You will first need to check if it actually is overheating. The reason is. If the head is cracked or gasket blown then you can get a false boiling which is compresion from the cylinders blows through the crack in the head or gasket causing the coolant to blow out of the radiator cap.Fill the radiator to the top leave the cap off then start the engine.If the water blows out then you will need to remove the cylinder head check the gasket is ok. If its damaged replace if not get the head checked for crack's. If no water blow's when you start it check the thermostat is working properly. To check the thermostat put it a in a saucepan cover it with water bring the water to the boil. It should open before the water boil's but near boiling-point. If its ok then start the engine again leave it running until it boils and check the fan is running. If that's ok then its radiator problem. Their is no way to check if the radiator is ok you will need to get a new one. One last point. If the cylinder head or gasket are faulty it was caused by overheating so by just fixing the cylinder head problem is not a cure it will overheat again. Check the three things I mentioned at the begining and told you how to check them. Hope this help's. Cheer's

If your thermostat is stuck in the closed position , it will not let coolant circulate to the radiator and the engine will overheat quickly. Fans won't come on because the temp sensor for the fans is usualy in the radiator. If the thermostat dosn't send hot coolant to the radiator , the fans don't know they should be on.
Only solution is to replace the faulty thermostat. I recomend that you dont drive the car at all with the bad thermostat. major overheat could severly damage Heads , head gasket , engine.