Here are some common causes of overheating:
鈥?Thermostat - Severe overheating can often damage a good thermostat. If the engine has overheated because of another problem, the thermostat should be tested or replaced before the engine is returned to service.
鈥?Cooling system leaks - Loss of coolant because of a leak is probably the most common cause of overheating. Possible leak points include hoses, the radiator, heater core, water pump, thermostat housing, head gasket, freeze plugs, automatic transmission oil cooler, cylinder head(s) and block.
鈥?Fan - With mechanical fans, most overheating problems are caused by a faulty fan clutch - though a missing fan shroud can reduce the fan鈥檚 cooling effectiveness by as much as 50 percent (depending on the fan鈥檚 distance from the radiator), which may be enough to cause the engine to overheat in hot weather or when working hard.
鈥?Water pump - Any wobble in the pump shaft or seepage would call for replacement. In some instances, a pump can cause an engine to overheat if the impeller vanes are badly eroded due to corrosion or if the impeller has come loose from the shaft. The wrong pump may also cause an engine to overheat. Some engines with serpentine drive belts require a special water pump that turns in the opposite direction of those used on the same engine with ordinary V-belts.
鈥?Belts %26amp; hoses - Check belt tension and condition. A loose belt that slips may prevent the water pump from circulating coolant fast enough and/or the fan from turning fast for proper cooling.
The condition of the hoses should also be checked and replaced if they are over 5 years old.
Sometimes a lower radiator hose will collapse under vacuum at high speed and restrict the flow of coolant from the radiator into the engine. This can happen if the reinforcing spring inside the hose is missing or damaged.
鈥?Radiator - The most common problems radiators fall prey to are clogging (both internal and external) and leaks. Dirt, bugs and debris can block air flow through the core and reduce the radiator鈥檚 ability to dissipate heat. Internal corrosion and an accumulation of deposits can likewise inhibit coolant circulation and reduce cooling. A good way to find clogs is to use an infrared thermometer to %26quot;scan%26quot; the surface of the radiator for cold spots. If clogged, the radiator should be removed for cleaning or be replaced.
Backflushing the cooling system and/or using chemical cleaners can remove rust and hard water scale, but may do little to open up a clogged radiator.
When refilling the cooling system, be sure you get it completely full. Air pockets in the head(s), heater core and below the thermostat can interfere with proper coolant circulation and cooling. If the cooling system has no bleeder valves to vent air, you may have to temporarily loosen a heater hose to get all the air out of the system.
鈥?Excessive exhaust backpressure - A clogged catalytic converter is usually the culprit here, but don鈥檛 overlook the possibility of a crushed pipe or a collapsed double wall pipe. Check intake vacuum at idle. If it reads low and continues to drop, inspect the exhaust system.
鈥?Retarded or overadvanced ignition timing (may also contribute to detonation and preignition).
鈥?Overheated incoming air - On older vehicles with a carburetor or throttle body injection, check the operation of the heated air intake system on the air cleaner. If the temperature control valve is stuck so only heated air from around the exhaust manifold is drawn into the air cleaner, it may contribute to detonation and/or overheating. Also check the heat riser valve for manifold heat on older V6 and V8 engines. If stuck shut, it may be overheating the intake manifold.
鈥?Dragging brakes - A caliper that鈥檚 sticking or a parking brake that isn鈥檛 releasing may be making the engine work too hard.
My car is running hot and killing on me,i checked the radiator and changed my thermostat,still running hot?
pressure test your entire system. If its overheating it will go into %26quot;limp mode%26quot; that's normal protective action by the PCM computer. Also check that all cooling fans are coming on and shutting off at the desired temperature. Your problem may lie there. Check if there is any flow--your water pump might not be pumping. Make sure to %26quot;bleed%26quot; out all air out of system after thermostat replacement. An air buble will make it overheat.
My car is running hot and killing on me,i checked the radiator and changed my thermostat,still running hot?
The key question to start with is whether it only overheats on the open highway or when your stopped in traffic. The diagnosis is different depending if you happen to have one case rather than the other. Of course if a thermostat stuck closed, it would overheat both on the highway and stopped in traffic.
http://www.aa1car.com/library/overheat.h鈥?/a>
Radiator could be clogged.
Is fan running?
If its electric make sure its coming on.
If its manual make sure your belts are tight.
If its manual make sure your fan clutch is working.
Make sure fins on radiator are cleaned out.
Worse case you could have a cracked head.
Could be lots of things still wrong...did you check for:
low coolant or air in coolant
waterpump
fan(s) ( both engine and electric if applicable )
fan belt
fan relay
rad cap/cooling system pressure
blocked or cracked hoses and lines?
when it get hot does the fan work? if not then there is part of the problem.
you have a bad head gaskett
