How to Repair an Overheating Car

An overheating car can quickly change the way a person is able to get around. This article will explain how to diagnose and overheating car and repair the problem, in most cases avoiding a costly mechanic.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• Wrenches
• Screwdriver
• Gloves
• Replacement parts

1. It is always best to check the easiest most common problems first. First open the radiator cap and check the level of antifreeze. The radiator will be in the front of the car. This could have a fill tank or have the cap directly attached to the radiator. The fluid level should be to the top of the fill opening. If it is low refill and check for overheating by running the engine.

2. Next check the oil in the engine. Pull the dipstick out of the engine and check for a milky appearance. If the oil appears milky a larger problem exists and the car will need to be taken to a mechanic for a very costly repair.

3. If the above two steps have yielded no results it is time to diagnose the engine problem. The radiator will have two large rubber hoses going from it to the engine. There will be a top hose and a bottom hose. With the engine off, squeeze the top hose. If the hose is squeezable then we can continue the diagnostics. If it is not the hose has a support wire in it skip to step 5.

4. Let the car warm to operating temperature. With a glove on squeeze the top radiator hose. This hose will be hot so ensure you are wearing a glove. If the hose remains rigid it signals the car has a malfunctioning thermostat. If the hose remains squeezable and the car is still overheating it signals that the car has a malfunctioning water pump.

5. If the thermostat is suspected it must be removed and replaced. Follow the top radiator hose to where it attaches to the engine. You will find a small housing that connects the hose and the engine. This is the thermostat housing. Disconnect the radiator hose and remove the bolts securing the housing to the engine. Remove the housing and you will find the thermostat beneath.

6. To verify the thermostat is malfunctioning and for those who had a support wire in the radiator hose, place the thermostat in a pot of boiling water. Check to see if the thermostat is opening. If it opens it is not malfunctioning. If it is found to be malfunctioning, replace the thermostat in the reverse fashion from taking it out. Ensure all old gasket material is removed from the housing and engine and replace the gasket with a new one.

7. 
    
   Water pump removal

   If the thermostat is functioning correctly or the top radiator hose was squeezable then the water pump is the malfunctioning part. Follow the bottom radiator hose to where it connects to the engine. It will connect to the water pump. The water pump will occasional have a "weep hole" that you will be able to visibly be able to see where coolant has been leaking out. Remove the water pump and replace with a new one. This is an involved process as all the connecting belts and hoses will have to be removed to gain access to the pump. Ensure all gaskets are replaced when installing the new pump.

Tips & Warnings

• All bolts should be torqued to factory specs.
• These are the most common reasons for overheating.
• Hot coolant will be encountered during this process.
• Do not remove any components while engine is hot.