Car heat is cold until I add water and over heating with out telling me

Hi my Hyundai Santa fe 2002 heat is going cold then it goes hot when I add water to it then it goes hot and I think my weeping hole is leaking out the water pump when I'm in park or sitting more then anything but when I pit it in air it is cold not hot like my other cars have some when they over heated could all this be because some one left my overflow cap off and my radiator cap not working all the way or do I have major problems due to the over flow cap being lost with out me knowing and I drove it I put in a sealant for the radiator and block heads heating core and so on.. It seem
Experienced mechanics share their insights in answering this question :
Hello, thank you for writing in. There seems to be an issue that we need to take on first and foremost. This is the fact that you are having to add coolant to the system. This means the coolant is leaking either externally (onto the hot engine), or internally (being consumed with the air/fuel mixture). The best way to tell is to simply run the vehicle and watch for the leak. If the engine is consuming the coolant, you are likely seeing white smoke from the exhaust. This is most commonly resolved by replacing the head gasket. Common components to look for an external leak with are the thermostat and the water pump. Both would cause the symptoms you are explaining. Fore more help with the issue, contact our service department to schedule an appointment.

How to Identify and Fix Common car Problems ?

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If there isn`t enough coolant in your system, the heater core will blow cold air into your car. Solution: If you confirm that a low coolant level is the source of your problem, you simply need to top off your coolant. You may want to check for leaks as well if you just recently refilled your coolant.
Adding coolant does nothing to address the problem that caused your engine to overheat in the first place, but it often allows you to drive safely to the nearest repair station. “A professional will need to inspect your car`s cooling system,” says Reina. While driving, keep an eye on the temperature gauge.
This problem could be either an engine thermostat that is not keeping the engine at a constant running temperature (temp gauge steady in the center), or the heater control valve or controls are malfunctioning not allowing engine coolant into the heater core (passenger compartment).
Causes of this can be not having enough coolant, a broken thermostat, a damaged heater core bypass valve, or a blockage in the core itself. If you encounter any of these issues, you should never drive an overheating car. Have it towed to an auto shop if you must, but you never want to risk your car`s engine.
The auxiliary water pump moves hot water or coolant that has recently circulated through the engine block to the heater core. However, when the pump is not working, due to an electronics failure or the motor of the auxiliary pump being broken, the heater core will not be able to heat up.
Not only that, but the fill cap itself might be extremely hot to the touch, so for your own safety it`s important to wait until things have cooled off. There`s another reason why you should never add coolant/antifreeze to a hot car, and that`s catastrophic engine damage.
Low coolant: Whether caused by a leak or water evaporation, low coolant is the most common source of poor heater output. Thermostat: A stuck-open thermostat prevents the engine (and coolant) from heating up. Heater core: A clogged heater core restricts coolant flow, giving up little or no heat.
Common Car Heater Problems

The heater switching system might be faulty. The cabin air filter might be choked, restricting the airflow through the heater core. The thermostat valve might not be working right. The heater core might be clogged.

Dirty Flame Sensor

When your furnace blows cold air, try turning the heating unit off and on. If the air feels warm for a moment or two, then switches to cold, it may be that the flame sensor is dirty. With a dirty flame sensor, your gas burner won`t stay lit, causing the air to go cold soon after the furnace turns on.

Coolant leaks from the water pump are common and a clear sign that it`s time to replace the pump. The coolant is stored inside the water pump using a series of gaskets and seals. Once these parts wear out, loosen, or crack, you`ll end up with radiator fluid leaking out of the front of your car toward the center.
The pump may not leak coolant, but the pump mechanism itself may have failed. Over time the fins of the pump can actually wear down to the point where they are no longer moving coolant. Cavitation can eat away at the metal pump vanes and pump surfaces.
due to the overheating risk, a car with a leaking water pump should not be driven. coolant leaks allow air into the cooling system, creating air pockets where hot spots can occur and damage other components. if the water pump is leaking, consider getting the vehicle towed to a repair shop.
You`ll most likely hear a quiet clicking sound followed by air moving through the ductwork. You can also place your hand on a vent to feel for hot or cold air. If you don`t hear or feel anything within a minute or two of making the changes, your thermostat may need to be replaced.
Start your car`s engine and allow it to idle. Look through the radiator filler neck to see if the coolant flows. At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open. If you find the coolant is flowing, it means the thermostat valve is open.
Across almost all models of cars and trucks, the number one cause for a vehicle`s heater to stop working is a faulty or broken thermostat.
If you are regularly topping off your coolant, you have a coolant leak somewhere in the system. It can be difficult to identify where the leak is coming from. Often it is best to have a professional diagnose a coolant leak, but there are a few things you can check before bringing your car into a shop.
This deteriorated liquid can trigger severe harm to your engine by failing to control the temperature. Therefore, manufacturers suggest replacing the coolant periodically. It is recommended you change coolant after the first 210,000 km (140,000 miles) or 120 months, then every 30,000 km (20,000 miles) or 24 months.
Yes, run the engine

Running the engine helps to get any air bubbles out of the system. Do I need to run the engine with the radiator cap off whenever I add coolant to the radiator or only when I drain/flush the system? Yes.

While you can drive the car for a short time using water in place of the coolant, it won`t effectively protect your engine. This means its essential to get the problem that caused a low coolant level fixed as soon as possible, and the radiator filled with a 50/50 ratio of coolant to water.
Corrosion within the radiator is one of the leading reasons that coolant leaks. As the tubes get older and weaker, you may get sediment or debris inside that causes a leak. The sealing gasket between the tank and the radiator can also wear out, and that could lead to a leak.
A few things that cause automotive heaters to work less well are low coolant levels in the radiator, a faulty heater valve, or the thermostat is stuck open. Have a certified mechanic replace your thermostat if necessary or diagnose and repair other cooling system issues, such as leaking coolant.
Your Thermostat is Stuck Open

If the engine does not warm up as it should due to a stuck open thermostat, the heater won`t be able to build up the warmth needed. The result: your car`s heater may stop blowing hot air — idle or otherwise.

One way to check for proper coolant circulation is to check the upper and lower radiator hoses. The upper radiator hose should be hot, around 190–200 °F. (The safest and most accurate way to get this temperature reading is with an infrared thermometer.)
One of the most common yet serious problems that develop in the cooling system is a radiator leak. A crack or leak from the radiator can lead to significant loss of coolant or antifreeze. Without these fluids present in the cooling system, air bubbles start to develop.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Car heat is cold until I add water and over heating with out telling me
ANSWER : Hello, thank you for writing in. There seems to be an issue that we need to take on first and foremost. This is the fact that you are having to add coolant to the system. This means the coolant is leaking either externally (onto the hot engine), or internally (being consumed with the air/fuel mixture). The best way to tell is to simply run the vehicle and watch for the leak. If the engine is consuming the coolant, you are likely seeing white smoke from the exhaust. This is most commonly resolved by replacing the head gasket. Common components to look for an external leak with are the thermostat and the water pump. Both would cause the symptoms you are explaining. Fore more help with the issue, contact our service department to schedule an appointment.

Read Full Q/A … : Car heat is cold until I add water and over heating with out telling me

Water was spilled in the trunk which soaked the car battery. Car won’t start now. Does water destroy a car battery?
ANSWER : Hi, thanks for writing in about the concern with the BMW 320i. If the battery was submerged in water then it’s completely possible for the battery to short out and die. Your friend will need to have the battery replaced. Also be sure to get all of the water out of the trunk. Have a certified technician, like one from YourMechanic, help you guys out if you need assistance with replacing the battery. Good luck.

Read Full Q/A … : Car heat is cold until I add water and over heating with out telling me

Does extreme cold weather cause a car to heat up so fast,temperature gauge getting to the top
ANSWER : Hello, thank you for writing in. If you have only water in the radiator, and no antifreeze then more than just overheating can happen Often the freeze plugs in the engine will pop out causing issues, the engine block can crack, and other related issues. If there was antifreeze in the system, then your engine may have just overheated. The radiator also may have frozen and cracked. Its very hard to tell without performing an inspection on the vehicle. Check all of the hoses, the radiator, and the engine to try and find if there is a leak anywhere. If there is no leak you will want to check the quality of the coolant, the water pump, and the thermostat. Extreme cold conditions can effect all of these components and more. Make sure you are using a high quality antifreeze.

Read Full Q/A … : Car heat is cold until I add water and over heating with out telling me

A/C and heat are not working properly. Car blows heat in summer and cool air in winter.
ANSWER : Common causes of no cabin heat include malfunctioning blend door(s) (part of the in-dash ventilation network), a faulty or stuck heater control valve, a plugged heater core, stuck open engine cooling thermostat, collapsed hoses, and low coolant level. The cost to resolve the problem depends on which of the foregoing faults is the cause. If you desire a diagnostic to determine exactly why there is no cabin heat, please request a non functioning cabin heater diagnostic and the responding mechanic will come right to your location and get this resolved for you promptly.

With regard to your air conditioning system, if merely re-charging the system restored normal operation but the a/c ceased to function after a month or so, that scenario typically suggests a leak. Some leaks are really cheap to repair, like if a couple o-rings need to be replaced in system piping but if the leak is at the compressor shaft seal, that repair is more costly. It is not expensive to find the leak and diagnose the system and once the leak is found the mechanic can let you know of the exact cost to repair the leak and re-charge the system. If you desire that service please request an a/c system diagnostic – suspected refrigerant leak and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you

Read Full Q/A … : Car heat is cold until I add water and over heating with out telling me

My engine blew out due to my water pump leaking…i didnt have no problems with my car over heating, no steam, running weird,
ANSWER : It is quite likely that when the car was hit, the radiator may have been punctured which would have caused a lot of the coolant to leak out of the vehicle.

If the water pump failed or if it were low on coolant, there would have been overheating indications on in the dash, so you should have had some kind of warning either way that the coolant level was low.

If you’d like to get this fixed, consider YourMechanic, as one of our mobile technicians can come diagnose the leak firsthand and help address any other potential issues.

Read Full Q/A … : Car heat is cold until I add water and over heating with out telling me

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.

Read Full Q/A … : Car heat is cold until I add water and over heating with out telling me

Car will blow cold air but will not blow heat
ANSWER : The heater not working in some cases may be related to the overheating problem you are also having. This may be due to a faulty heater blower motor or potentially a bad heater core. As you may know, the heater core is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this warm coolant to heat the inside of the car with the help of the blower motor that blows the warm air through the vents inside the car. When the cooling system is not properly circulating coolant through the motor, this results in the warm coolant not being pumped through the heater core properly in order to warm the inside of the vehicle.

Engine overheating can be caused by a number of things such as low coolant levels, a faulty thermostat, or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds. When this switch is not working properly, this can cause the fans to come on intermittently, all the time or sometimes not at all. When this happens you will notice a temperature spike and drop occasionally as the fan comes on and off. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. As mentioned above, this also restricts the warm coolant from flowing through the heater core which uses this to blow warm air into the cab of the vehicle. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.

Read Full Q/A … : Car heat is cold until I add water and over heating with out telling me

Car does not get to normal engine temperature
ANSWER : Hi there:

There could be multiple issues causing your engine to not reach normal operating temperature. However, continuing to add water instead of coolant to your motor could be very harmful; especially to cooling hoses, connections and cooling system components. The coolant should be mixed at a 50% water to coolant ratio. In order to determine why your engine overheated in the first place and why it’s temperature is low now, the best thing to do is have a professional mechanic complete an engine is leaking coolant inspection. This will allow them to inspect your cooling system for issues and recommend the right repairs.

Read Full Q/A … : Car heat is cold until I add water and over heating with out telling me

Eric smoalih

I am a certified master technician with the National Institute for Automotive Service Excellence (ASE), and I have been working as an auto mechanic for over 15 years. I am passionate about my work, and I take great pride in helping people keep their cars running smoothly.