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Car Overheating

Have you ever experienced with an car overheating (engine overheating)?
195 to 220 degrees Fahrenheit (90 to 104 degrees Celsius) is a “normal” temperature range where the most engine operates. To get proper emissions control, good economy and fuel performance, it is important to have a relatively constant operating temperature. However the engine will overheating when the engine to run hotter than normal and it will causing a problems.

Water and ethylene glycol antifreeze is a mixture content (with a ratio of 50/50) in your engine’s cooling system. With the radiator cap, pressure can be held when the cooling boil at temperatures 225 degrees. An increase in the boiling temperature of 50/50 coolant mixture can reach 265 degrees F with a 15 PSI radiator cap. The boiling temperature can reach 276 degrees F with a 15 psi radiator cap, if the maximum recommended concentration of antifreeze to water is upped to 70/30. So the boiling cooler and the overheated engine can be prevented by the radiator cap, and in this case it plays a significant role in order that issues do not happen. For any reason, your engine is in danger of overheating if the temperature is climb more than a normal range.

Most Common Causes Of Engine Overheating

Decreasing the ability of the cooling system to dissipate, absorb and transport heat can lead to overheating. A common thing that causing the engine overheating: a defective radiator cap, a low coolant level, loose or an eroded water pump impeller, a coolant leak (through external or internal leaks), a collapsed lower radiator hose, an inoperative electric cooling fan, a defective thermostat that doesn’t open, a slipping fan clutch, accumulated deposits in water jackets that cause poor heat conductivity inside the engine, or poor airflow through the radiator.

Naturally the temperature flows from higher temperature area to lesser temperature area. Contact with a cooler liquid constantly is the way to cooling down the hot metal. To able to do that keep the coolant in constant circulation. If there any problem with thermostat, loose of coolant or the water pump that causing the circulation stops, then it will make the engine temperature rising and engine become overheating.

The heat that soaks up into the engine must be get rid by the coolant. The engine will run hot when the cooling efficiency decreases, it can be causing by gunk or rust, sediments that block internal passages the radiator or radiator is clogged by debris or bugs. Same issue also happen if there not enough air pulled to the radiator due cooling fan is not spinning fast enough or is not engaging.

To prevent the engine does not overheat, the engine’s average temperature should be kept within the normal range, and all this job done by the thermostat. So the engine will overheat if thermostats fails to open and it will effectively block the flow of coolant.

Another cause the engine become overheat is exhaust restrictions. The heat from the engine is carried by the exhaust, and heat can grow inside the engine due to the flow of the exhaust has been restricted if the pipe has been crushed or crimped, or if the catalytic converter is restricted.

For your note, faulty coolant sensor sometimes causing your warning light or your temperature gauge coming on. So not all issue caused by an engine that overheating. Check if there an air trapped under the sensor or coolant level is low.

Consequently If The Machine Is Overheated

The engine will lose a power and it may rattle and ping when the engine is overheat and start to detonate. It can causing damage the rod bearings, rings and/or pistons if the detonation continues.

Pistons scuffing may caused by engine overheating. Cylinders and pistons can be damaged by being scraped by a swollen piston where there is no more room for expansion due to the effect engine gets hotter and hotter.

Possibly the exhaust valves can scuff and stick in their guides. It can lead to compression loss, damage the guides and the valves.

Blown head gasket is another consequence causing by engine overheating. Swelling of aluminum may occur due to heat. This aluminum swell could be three times faster than cast iron. In areas restricting coolant flow such as the narrow area that separates the cylinders and in the hottest areas such as those between the exhaust valves in adjacent cylinders may occur head swelling due to distortion of thermal stress. When the heads gets too hot, it can crush because typically aluminum head swells most in the middle. Crushing the head gasket usually can cause leak coolant into the cylinders or leak compression between adjacent cylinders.

Overhead cam to seize and break also can causing by engine overheating.

The old radiator could be burst under the additional pressure due engine overheating can causing heater hoses and old radiator stress. radiators with plastic end tanks also can damage when steam generated inside the cooling system.

Do NOT ignore hot warning light/lamp. When car overheating while driving and the warning on, you should stop driving. Turn the engine off, find the problem that trigger the warning and fix it, make sure let it cooling down before you inspect the issue. Don’t risk your travel by ignoring the hot warning light on.

Something Which Must Be Checked When Overheating Occurs

Bad Thermostat

Good thermostat can damage by severe engine overheating. Before the engine is returned to service, check and do test the thermostat or replace it if you found overheated causing by another problem.

This way how to check the thermostat, start the engine and read the temperature using an infrared non-contact thermometer or feel the upper radiator hose. If hose doesn’t get hot, it tell you the thermostat isn’t opening, until the thermostat opens and engine warmed-up the hose should not feel uncomfortably hot.

Remove the thermostat and then dip it into a pan of boiling water and make sure it open. Use the thermometer to check exact opening temperature. This another way how to check the thermostat.

Thermostats Bleeding

Make sure the temperature rating is same with the original if the thermostat need to be replaced with the new one. The thermostats temperature rating with 192 or 195 degree is required for some light trucks and cars since 1971. Oil and fuel consumption, emissions and ring wear may increased when in an attempt to “cure” a tendency using a cooler thermostat (160 or 180). When the engine fails to reach its normal operating temperature, there will be major performance and emission problems caused by wrong thermostat, as this prevents the computer from entering a closed loop, this only occurs in newer vehicles with computerized engine controls.

TIP! Air can trapped under the thermostat when refilling the cooling system. This can prevent the thermostat from opening and can cause the engine to overheat because a steam pocket can be formed by it. Bleeder valves available on some cooling system and while refilling the system it can be opened to vent air from the system. Make a small hole on thermostat by drilling it if there no bleeder valve on you cooling system. This can prevent the air is not trapped inside the engine block and will allow air to escape past the thermostat. There a feature on some thermostats that allow air to escape called “jiggle valve”, it a small hole in the thermostat with a pin.

Cooling System Leaks

The probably most common cause the engine is overheating is coolant leak. The leaks point possibility include hoses, block and cylinder head(s), automatic transmission oil cooler, freeze plugs, head gasket, thermostat housing, water pump, heater core, the radiator.

Visual inspection is needed on entire cooling system and should be done carefully, then continue with pressure test for radiator cap and cooling system. Internal leaks just like cracks in the head or block and seepage past the head gasket can be revealed by this pressure test. With no lose in pressure, for 15 minutes a good systems will able to hold 12-15 psi. There an internal leak if there a pressure leaks, cracked engine block or cylinder or possibly a bad head gasket.

Radiator cap should be tested for pressure test, because low pressure ratings or weak cap can allow coolant escape from the radiator and the coolant’s boiling point can be lower.

Leaky Head Gasket

Coolant can seep into the engine’s crankcase or cylinders caused by leaky head gasket. And the repair is an expensive. White steam in the exhaust and loss of coolant without any visible external leak, especially after restarting the engine is the symptom. Do pressure test the cooling system to diagnose a leaky head gasket, or use a special leak detection fluid (usually with blue color) with the “block checker” method that pushing the air into the cylinder through the cooling system. The color of the liquid detector will change from blue to green when in the coolant has a combustion. Add a sealer product to the cooling system is temporary fix when a leaky head gasket occurs. However the head gasket need to be replaced if there the sealer cannot fix the leaks or it’s has bad leaks.

Fan Not Working

The faulty fan clutch on the mechanical fans is a common problem that caused the engine overheating, the fan’s cooling effectiveness is reduced by 50% (the radiator distance with the fans also determines this) because the lost fan shroud can cause the engine overheat when it working hard or during in hot weather.

Engine overheating commonly caused by defective fan clutches. Per year the average drive efficiency loses about 200 rpm, this is due to the deterioration of shear clutch liquid characteristics over time.

NOTE! When you replace the water pump, then usually a fan clutch also need to be replaced, because commonly the life time a fan clutch on average same as water pump.

You need to replace the fan clutch if signs of a liquid leak begin to appear on the fan clutch (from the clutch hub radiating outward oily streaks), when engine is off it’s no resistance or spins freely with little, or when the fan is pushed in or out it’s a wobbles.

When the air conditioner is on and when the engine gets hot, check to see that the fan cycles on if it’s an electric cooling fan. Check the temperature sensor, fan relay and fan motor wiring connections if you found the fans is fails to come on. Into the battery, try jumping the fan directly. If fan runs, then it tell the problem is the sensor, wiring or the relay. However, if the fan does not run, then you need to replace the fan motor because the problem is the fan motor is bad.

To get adequate cooling at low and idle speeds, the fan should spin fast enough if it is a hydraulic cooling fan.

Leaky Water Pump

It will call for replacement if there a seepage or any wobble in the pump shaft. Engine overheat can caused by a pump if there an impeller that come loose from the shaft or due a corrosion impeller badly eroded. Also, another cause of engine overheating is the wrong pump. Specialized water pumps that turns in opposite directions on the engine with an ordinary V belt are required by some engine with a serpentine drive belt.

Although it looks normal spin on a water pump pulley, not turn and loosen up on the pump shaft sometimes happen to the water pump impeller, however it’s so rarely happen. There will no circulation or just a little of coolant throughout the engine, if the impeller does not spin. The way to check if the impeller is the problem, you need to see the impeller is tight on the shaft, and you need to remove the water pump to be able to do this check. Eroded also may happen to impellers from plastic material. Cavitation erosion also happen to the water pump housing and/or impeller. Reduction of coolant flow can lead to engine overheating, due blade area loss or increase in clearance between impeller and housing.

Cavitation Damage

Slipping Belt

Belt condition and tension should be checked. When it loose, it will prevent fan from turning fast for proper cooling and/or the water pump will not circulates the coolant fast enough.

Lower Radiator Hose Collapsing

Engine overheating may occur when a lower radiator hose or a pinched hose (lower and upper) collapsing and blocking the coolant flow while the engine is running. There usually a metal reinforcing wire inside the lower hose that looks like a large spring. When the water pump is pulling water through the hose it will prevent the hose from collapsing. It may collapse when it has failed or the wire is missing due to corrosion.

Dirty or Plugged Radiator

The ability of the radiator to reduce and eliminate heat will be reduced when the flow of air through the radiator is blocked by debris, dirt and/or dead bugs. Coolant flow also can be blocked by an accumulation of deposits and internal corrosion. Use infrared thermometer to find out internal clogs by scanning the radiator surface for cold spots. Clean or replace the radiator if clogs is found. Hard water scale and rust can be removed using a chemical cleaners or back-flushing the cooling system, however it may work on clogged radiator, even only do little to open up.

Make sure to get completely full when refilling the cooling system. Proper circulation and cooling of the coolant may be disrupted by air pockets in the head(s), heater core and below the thermostat. If there no bleeder valves on the cooling system to get vent air, and the temporary way to get all the air out of the system you need to loosen the heater hose. At engine idle, check the intake vacuum. You need to inspect the exhaust system if the intake vacuum reads low and continues to drop.

Excessive Exhaust Back-pressure

The heat will be back up inside the engine due the exhaust flow is restricted by a clogged catalytic converter. A collapsed double wall pipe or crushed exhaust pipe is also another caused the engine overheating.

Overheated Incoming Air

On the air cleaner, check the heated air intake system operation for older vehicles with throttle body injection or a carburetor. Overheating of the engine and or detonation can be caused by stuck of the temperature control valve, it occurs because only the hot air from around the exhaust manifold is drawn in to the air cleaner. On older engines (v6 and V8) you need to check the heat riser valve for manifold heat.

Dragging Brakes

Regularly check the brakes, and fix it if there an issue that caused the parking brake that isn’t releasing properly or a disc brake caliper sticking. Both issue may caused by the engine that work harder than usual to overcome the friction.

Overworking The Engine

Most passenger cars today have a cooling system with a little excess capacity to handle extra heat generated high speed mountain driving in hot weather or towing. If you want to improve the cooling capacity, then you need to replace the stock radiator with thicker or larger radiator.

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