Thursday, October 6, 2011

What's causing my car to overheat? Is it a thermostat or water pump?

The vehicle is a 2003 ford focus with a 2.0L motor sohc... I find it odd that my car started to overheat once I changed my air filter. I've been told that it can possibly be the thermostat or water pump. When it got close to being hot, I noticed that the fan was on. However, the coolant did rise a higher than the 'max' mark as if I had too much in it. How do I know if it's the thermostat or the water pump? Any other suggestions would be of help, also. Thanks...
What's causing my car to overheat? Is it a thermostat or water pump?
more than likely the thermostat. Pumps can and do break at the shaft internally, but its pretty rare that they do. The pump is always circulating the coolant. When the thermostat opens, it allows the coolant to cycle from the radiator to the engine. If you are table to perform the task of replaceing the stat yourself for a few bucks, then its worth it and will probably be the fix vs taking it to a shop and paying 70 dollars to diagnose it and what ever they charge to repair it.
What's causing my car to overheat? Is it a thermostat or water pump?
OK, the thermostat opens and closes by temperature. So, while parked in the driveway and cold or cool. Open the radiator cap. Start the motor, let idle until warm, keep idling. At some point the thermostat should open causing the pump to circulate the water, you can see the water moving across the radiator( not just giggling around). This says the pump is working and the thermostat too. If this does not occur then start by changing the thermostat( cheep), then if that does not change the test results, change the pump.
Could be the radiator fans are not on due to a bad radiator motor.
It might be your radiator, it could be plugged up. Take it to a radiator shop. They usually check for free, and they'll tell you what's wrong and give you an estimate. New radiators are available at auto parts stores at a cheaper price than radiator shops.
take out the thermostat and boil it in a pot of water. if it opens, it works and the problem is somewhere else. possibly the radiator or other hoses being plugged, i doubt its the water pump though.
OK here are two things you can do 1.see if you can take out the thermostat,then put it in a cold pot of water and then turn on the stove and watch the thermostat open up.if it doesn't open up. its the thermostat.2.are you hearing a high pitch noise from the front of the engine?try and get a long metal

tube and put it on top of the water pump(be very careful in doing this,because the car has to be running)put your ear to the other end and listen to it. there should be smooth humm sound to it.if it sounds like something grinding its the pump.the first one is the cheapest and once you have fixed the problem get the engine flushed out to prevent further problems
1) I don't think the filter has anything to do with the overheating problem since wrong filter media micron affects only the air flow and the catalytic converter will correct the air/fuel mixture.



2a) When the engine has cooled down a bit, carefully open the radiator cap, start the engine, then check if the water is streaming, or stalled. If water has stalled, then you probably have a water pump problem (but considering your car year model, this is much too early to occur.).



2b) Coolant level rising while the engine is running (not necessarily on high temp) could be an indication of a blocked/restricted engine cooling system; possibly caused by an accidental dropping of some kind of solid material either into the radiator, or the coolant container (therefore, not a pump problem). If so, check the coolant container, or have the radiator serviced at a radiator shop.



2c) A distant probability is a malfunction of the thermostat sensor, this is generally located at the lower left bottom side of the radiator (viewed from the front of the car) ...turning on only at higher temp threshold...



Otherwise, take the car to a Ford-authorized service shop. Overheating problem should be corrected immediately as this will cause progressive engine problem.
It probably is the thermostat. how many miles are on the car ? I doubt thats its the water pump as it would show leakage as hey have a drain hole if the seal goes out.