Overheating

Van overheated, had towed to mechanics house, tested for head gasket and claims it isn't blown,changed thermostat, and water pump along with timing belt…Van still overheats. What could cause this ???

My car has 233000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
If the engine cylinder head is not leaking, then you have a radiator fan that is not coming on or the radiator is not flowing coolant. You could take the temperature at the top and bottom of the radiator to see if the coolant is flowing and is getting cooled by the radiator. If the radiator is not flowing the coolant properly, it will not cool the coolant to the engine and cause the engine to overheat. If you need help having this checked, a certified mechanic can verify the cause of your overheating issue and perform the necessary repairs to have this resolved.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

The most common reasons a Kia Sedona is overheating are a coolant leak (water pump, radiator, hose etc.), the radiator fan, or a failed thermostat.
There`s a leak in the cooling system – Most often, a leak in the cooling system is what`s causing your car to overheat. The radiator, hoses, water pump, head gasket, and thermostat housing are all components of the cooling system, and all can be susceptible to leaks.
Reasons a Car Overheats

This is often due to a leak or blockage somewhere in the engine cooling system or other components. Other sources may be from a faulty or broken water pump or radiator fan, or from a clogged coolant hose. Further reasons could include: The cooling system is not working properly.

With a normal top-mounted thermostat you need drain only part of the cooling system . Do not drain it while the engine is hot — you may be scalded. Wait for the engine to cool. Drain the coolant from the radiator tap, or from the bottom hose, until it is below the level of the thermostat housing.
If you notice that your engine overheats, the coolant temperature sensor could be the problem. At times, the coolant temperature switch may fail such that it starts transmitting hot signals permanently. This causes the computer to erroneously counterbalance the signal, thereby causing the engine to misfire or overheat.
Technically speaking yes you can use plain water in your cooling system but it isn`t recommended as a long term solution and certainly not in extreme weather conditions.
The air conditioner can cause an engine to overheat quickly because it makes the engine work harder. Even though it`s hot outside, if you turn off the AC, you may be able to avoid overheating, especially if you take the next step, which we apologize for in advance.
Why is my car overheating but it has coolant in it? It could be that the coolant concentration is not correct, or you may have a bad thermostat, a failed water pump, broken drive belt, or a bad radiator or radiator fan.
How long can a car overheat before damage occurs? It only takes 30-60 seconds of overheating for permanent damage to infiltrate a vehicle. As soon as you notice signs of overheating, you need to act. Failure to do so might result in troubles like coolant leaks, damaged radiator caps, and a faulty cooling fan.
Your overheated engine may still be running, but it`s not fine. You risk costly damage to your engine if you keep driving. DON`T panic. Your engine may have lost its cool, but now is the time for you to keep yours!
With the engine off, open your hood and locate the water pump pulley. With gloves on, grab it and wiggle it back and forth. There should be no movement, if there is, this along with the noise is a good indication you may have a water pump problem.
If your vehicle`s engine overheats, it could be due to failing spark plugs. Overheating can happen for a number of reasons that can cause your engine to be too hot. This can harm your engine parts and lead to expensive repairs down the line.
If you notice that the actual temperature of your room is at least five degrees warmer than your desired temperature and your air conditioning system doesn`t kick on, you could have a bad thermostat. If you`re still using a manual version, use this time to upgrade to a smart model.
As with all other systems, your thermostat will eventually become old and outdated. The lifespan of most home thermostats is 10 years. However, you may need to replace yours sooner as newer, more efficient thermostats enter the market.
One of the most common causes of overheating is problems with the radiator. Your car`s radiator pulls heat away from the engine to keep it cool. Sometimes, radiators can fail, or debris and particles can build up and stop the radiator from working properly.
Faulty Thermostat

Once the engine reaches operating temperature, the valve will open and coolant will begin to flow through the engine. A faulty thermostat might remain closed even when the engine is hot, which can quickly lead to overheating.

The absence of a thermostat makes it impossible for the engine to attain optimum temperature; for this reason, the control unit keeps assuming that the car is still on cold start mode, hence burning more fuel for as long as the car is running, hence compromising on fuel efficiency..the main reason why all vehicles …
Don`t do it. Cooling systems are designed to operate with a thermostat in place. With no thermostat, engine warm-ups will take a long time. Also, I have seen cases where with no thermostat, coolant circulates so quickly through the system that combustion heat isn`t efficiently removed, and the engine overheats.
There are four types of temperature sensors that are most commonly used in modern-day electronics: thermocouples, RTDs (resistance temperature detectors), thermistors, and semiconductor based integrated circuits (IC).
One of the most common causes of overheating is problems with the radiator. Your car`s radiator pulls heat away from the engine to keep it cool. Sometimes, radiators can fail, or debris and particles can build up and stop the radiator from working properly.
One of the most common causes of overheating is problems with the radiator. Your car`s radiator pulls heat away from the engine to keep it cool. Sometimes, radiators can fail, or debris and particles can build up and stop the radiator from working properly.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

car is overheating and leaking water and anti freeze
ANSWER : Coolant leaks can occur because of cracked hoses, leaking gaskets, faulty water pumps, or damaged radiators. When the coolant level goes low, the engine will start to overheat due to the low coolant level. I would first recommend giving the cooling system a visual look over. If it is not obvious where the coolant leak is coming from, I would recommed having the cooling system pressure tested in order to determine the leak source. If you would like to have your cooling system pressure testedcoolant is leaking inspection, consider YourMechanic, as a certified technician can come to your home or office to inspect your cooling system.

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My 2003 honda civic EX 1.7L is overheating. I replace the thermostat, replace the cooling fan temperature switch, remove the radia
ANSWER : It is likely your engine has a blown head-gasket, worn out water pump or somehow has a huge air bubble inside the engine that needs to be bled. The drop in engine temperature while on the freeway is actually a good sign – it indicates your radiator is getting good coolant flow, and the radiator is doing its job, transferring heat out of the engines cooling system. A YourMechanic certified technician can come to your location to perform a Car is overheating Inspection on your vehicle and help you diagnose and repair this issue.

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My 2009 Equinox is overheating intermittently. It overheated in the summer and tnen not again for 3 months then twice in one week
ANSWER : Check the coolant level to be sure it is adequate. Of course, if the coolant level is low enough to cause overheating, you may have a coolant leak. If the overheating is intermittent that would point to a possibly sticking thermostat, malfunctioning controls for the cooling fans, or the fans themselves, and possibly an engine operating condition such as an excessively lean air fuel ratio. Other common causes of overheating include low coolant level, a plugged radiator, collapsed hoses, and a faulty water pump or drive belt. Certain engine faults, such as a leaking head gasket or poor engine running condition can also cause overheating. If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an engine overheating diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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Engine Overheating after 20-30 minutes. Why?
ANSWER : Hi there. One of the easiest ways to test a water pump is to carefully place your hand on the lower radiator hose while the motor is running. Two things should happen; first, as you suggested, the hose should feel "hard" and you should always feel motion through the hose. One other thing to check is your heater. If the heater is not working (supplying hot air), then you’ve got an obstruction inside the heater core; which can also create overheating problems. If you can’t resolve your issues soon, feel free to contact one of our professional mobile mechanics and have them complete a car is overheating inspection.

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Overheating and boiling out the reservoir.
ANSWER : Hey there. The next thing you need to do is confirm the thermostat is opening and test to see if the radiator is clogged or not. Begin by warming your car up. Don’t drive it, just let it idle or hold it on a high idle. Depending on the ambient temperature, this can take a half hour or more for the thermostat to open. You will know the thermostat is open by touching the upper radiator hose. The hose that comes off of the thermostat housing. When it begins to get hot, the thermostat is opening. The stat will cycle open and closed during the warm up process. A motor is not fully warm until the stat reaches a point of equilibrium. Meaning, it stays open at a constant amount. If your car begins to overheat and the upper radiator hose does not get hot, you will need to figure out what is going on with the thermostat. It could be installed wrong or even bad. I have had new stats be bad several times.

If the stat opens correctly and your car is fully warm, take it for a quick spin around the block. Come back to a stop in your driveway or other parking spot, turn the motor off, key off, open the hood and reach in and touch the radiator from top to bottom and side to side. You are feeling for cold spots. They will be obviously cold in comparison to the rest of the radiator. It is normal for the lower part of the radiator to be colder than the top. That only means the radiator is cooling as it should.

If after doing these two things your car still overheats, it is time to consider head gasket problems. You can use a block tester kit from your local auto parts store or you can book and appointment with us. Testing for head gasket problems can be cumbersome and only experience will allow you to make an accurate determination. I recommend a having an overheating inspection to have this accurately diagnosed and corrected.

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Car started overheating two days ago. Changed the thermostat and the water pump, still overheating 1998 Chevy Lumina
ANSWER : Hi there – you may still have a problem with a clogged radiator, or the auxiliary cooling fans are not coming on properly. I recommend a engine overheating inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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Got new water pump less than 9 months ago. Now boiling sound and overheating smell. Temp says its good
ANSWER : Hello. The overheating issue your vehicle is having is likely not caused by the water pump once again. Though an inspection of your water pump performance should be checked when trying to diagnose this issue. The temperature gauge not going up to hot when the water is boiling will be a malfunction of the coolant temperature sensor. Overheating is likely caused by a faulty thermostat, a clogged coolant system, coolant system leak, or a bad head gasket. I suggest to have a technician perform an inspection of the possibilities I just mentioned including the coolant temperature sensor and it’s related wiring to help pinpoint exactly why the vehicle is overheating.

You are able to find a technician and schedule an appointment for your vehicle overheating here

https://www.yourmechanic.com/services/car-is-overheating-inspection

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My heat in my car stopped working two days ago and now my car is overheating. I put antifreeze in my car and it’s still overheating 2006 Pontiac Grand Prix
ANSWER : Hi there – you may have 2 related events here, a coolant leak, and a problem with the heater system. The current issue may be air inside the cooling system, which can cause overheating, and a lack of heater function. The lack of heater function could have 5 causes: the engine is not getting up to correct temperature (center of the gauge) due to a malfunctioning thermostat, the heater control valve is not letting hot coolant into the heater core, there is a restriction in the heater system that is preventing adequate hot coolant flow through the heater core, the heater fan is not working to transfer heat from the heater core to warm air for the passenger compartment, or the air blend doors inside the heater are not working properly to route warm air to the desired vents. I would recommend a heater system inspection](https://www.yourmechanic.com/services/heater-is-not-working-inspection) by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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