My car has had overheating problems for a year and i dont know why???

might be a faulty water pump not circulating the coolant

Remove the radiator cap, let the car run. When the car is at temp. and the thermostat opens you should see coolant circulating in the radiator. If there is coolant flow and you know for a fact that the engine is not actually hot,(check with a laser thermometer: point the laser at the engine block and read temp.) then you more than likely have a problem with the coolant temp. sensor. Check the connections, replace the sensor.
If you do not see coolant circulating in the radiator then you have an issue with either a thermostat, water pump or possibly a blockage or at worst a problem in the head. Check the overflow with the car running, if it is steadily "blowing bubbles" in the over flow (like someone blowing bubbles into a cup with a straw) then there is compression leaking into the cooling system and there is a problem with the heads. Remove the heads and have them checked for cracks at a machine shop.
If there is no "blowing bubbles" then I would remove the thermostat, run and check for circulation in the radiator again. If it is flowing, then replace the thermostat. No flow, Check the radiator with a laser thermometer. With the car at temp. point the laser at different areas of the radiator and see if you have "cold" spots. If you do then you have blockage at the radiator. If you have consistent readings across the radiator that is not "cold" then change your water pump.
I hope this has been helpful and helps you to solve your problem.

CHECK COOLANT LEVEL MOST NEWER VECHICLE DONT HAVE RADIATOR CAP YOU HAVE TO POUR COOLANT IN THE COOLANT OVERFLOW JUG THE COOLANT WILL GO TO RADIATOR. IF THE COOLANT OVERFLOW JUG EMPTY ADD COOLANT UNTIL COOLANT LEVEL STOP DROPPING AT STAY AT FULL COLD MARK.IF COOLANT OKAY,NEED TO REPLACE THERMOSTAT AND COOLANT OVERFLOW JUG PRESSURE CAP. IF ALL BEEN DONE. MOST OF THE TIME WHEN CAR OVERHEATING WHILE MOVING. RADIATOR CORES STOPPED UP OR RADIATOR GRILLE DIRTY OR RESRICTED.ENGINE BLOCK COOLANT PASSAGES CLOGGED AND HEATER CORE CLOGGED.CHECK WATER PUMP SEE IF WATER PUMP WEEP HOLE LEAKING IF SO REPLACE WATER PUMP.IF ENGINE OVERHEATING AT A LONG TRAFFIC LINE ENGINE COOLING FANS NOT RUNNING EITHER COOLING FANS FUSE AND RELAYS BAD.OR ENGINE COOLANT TEMPERATURE BAD. THE ENGINE COOLANT TEMPERATURE SENSOR TURNS ON COOLING FANS AT A CERTAIN TEMPERATURE IF SENSOR BAD FANS WONT TURN ON. MAKE SURE YOU HAVE 50 /50 MIXTURE OF COOLANT AND WATER IN COOLING SYSTEM.

COULD BE THERMOSTAT IF TOP RADIATOR HOSE IS NOT HOT AND BOTTOM RADIATOR HOSE GOING TO WATER PUMP IS HOT THE THERMOSTAT STICKING PARTIALLY CLOSE.IF TOP HOSE IS HOT THE RADIATOR,ENGINE BLOCK HEATER CORE NEED FLUSHING OUT.IF WATER PUMP WEEP HOLE LEAKING REPLACE WATER PUMP, FAULTY WATER PUMP WILL CAUSE ENGINE TO OVER HEAT.REPLACE RADIATOR CAP MAKE SURE YOU HAVE 50 / 50 MIX SOLUTION ANTIFREEZE AND WATER IN COOLANT SYSTEM. IF ALL LOOKS GOOD CHECK ENGINE OIL ON DIP STICK, IF OIL IN DIP STICK LOOK LIKE MILKSHAKE YOU HAVE BLOWED HEAD GASKET THAT WILL CAUSE ENGINE OVERHEATING WHILE DRIVING CAR IN SHORT DISTANCE AND ENGINE OVERHEATING.

Well....deep breath.......it's not bad.

1. Check your radiator coolant level

2. Check/Test radiator fan

3. Test/Replace radiator cooling fan relay

4. Replace the thermostat

5. Check/Replace the coolant temp sensor

6. Replace the water pump.

Sobrien.

If the car is overheating, especially in cool/cold weather you have a serious problem which needs to be addressed immediately. I very much doubt that the coolant temperature gauge is giving an incorrect reading and if you drive the vehicle with this problem you are risking expensive engine damage. In any event a mechanic can easily use another water temp gauge to check if the gauge in the car is giving a faulty reading.

If the thermostat has been removed - as you say - then there is nothing mechanical isolating/blocking the full flow of coolant between the radiator and engine despite the engine operating temperature.

Removing a thermo because of a previous overheating problem is not a sensible move because it does not address the underlying cooling problem issues. An old or faulty thermo should always be replaced with a new one and the causes of the overheating investigated and fixed. The fact that the thermo has been removed suggests that there was a cooling problem previously and it is likely that it was not due to a sticking thermostat.

Overheating can be caused by and one or more of the following:

1. Low coolant level. Check the coolant and top up. All coolant hoses (including heater hoses) need to be checked for deterioration and leakage. Suspect hoses need to be replaced .

2. A sticking thermostat which impedes the flow of coolant between the radiator and the engine when the engine warms up. A new thermostat needs to be fitted.

3. Debris in the coolant which is impeding coolant flow through the engine. Coolant needs to be changed every 2 years and the system flushed to avoid this problem and to address deterioration of the coolant mix.

4. Air locks in the cooling system from the inadequate bleeding of air from the system.

5. A faulty / corroded water pump. If the water pump has never been changed or you have no record of it being changed in the last few years then it needs to be removed, checked and replaced unless in good condition. A faulty water pump cannot push coolant through the system (or flow it fast enough) and your engine will definitely overheat.

A badly tuned engine can also cause an engine overheating problem in certain circumstances but in your case I suspect the issue is definitely with the cooling system as outlined above.

We cannot test and inspect your car so it is not possible to identify the exact cause of the problem in your case. I hope this helps and please get it checked out straight away by a reputable auto shop. Otherwise you are risking expensive engine damage and having to replace the vehicle entirely.

Cheers

The coolant flush on radiator doesn't do any good. Since you have changed all the key components and still gotten overheated, then the root cause of the problem is the radiator. It got clogged up in small tubes blocking coolant flow. No matter how good the water pump is working but the radiator got clogged up, coolant is not circulating therefore the heat from the engine can't be dissipated to the radiator. Replace your radiator, don't even think about rebuild it. It has been used for 11 years. Make sure to have the correct coolant/water ratio to keep radiator life for years. Good luck.

The engine overheat is due to inefficient cooling. Therefore, there is coolant in the radiator but if it doesn't circulate inside the engine water-jacket to remove the heat generated from combustion's chambers, then it still causes overheat. If this keeps happening then it can cause the engine head wrapped then leaking from the gasket as people called blowed head gasket. It could be: 1- Thermostat is not opened. 2- Water pump is not working. Before starting to replace parts, it needs to verify it it is the root cause of the problem. Take out the thermostat and run the engine to feel if there is water flowing inside the upper hose. A- If it is not then water pump is not working. B- If is, then run the car a few days without thermostat to see if it causes overheated. C- Running car without thermostat still causes overheat then there are some clogging up in the water jacket defeating the cooling efficiency--> Need a good flush. Good luck.

hard to get to and difficult job...are you sure you dont have cracked head? is there water in the oil....does the oil look milky? look in the radiator is there oil residue in the coolant........

many things could cause the overheating. broken water pump impeller, stuck thermostat, clogged radiator, inoperative cooling fan on the radiator.

i would first check to see if the cooling fan on the radiator is working. when it reaches operating temp (or surpasses it in your case), see if the fan attached to the radiator kicks on. if its not on, then either the fan has failed or the temp relay to kick on the fan has failed. also, make sure the connector is plugged in.

after its at operating temp, turn off the car and feel the radiator. if you feel cool spots, then it is clogged and needs replacing.

wile under the hood and car is off, feel the upper & lower radiator hoses. if one is hot and the other is cool, then either the water pump (actually the impeller on it) has failed and is not circulating coolant through the radiator. a common problem in this model.

but it could also be the thermostat. if failed, it would not allow coolant to flow & circulate.

hopefull one of the above items is the problem. good luck.