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9

My top suspect would be a radiator fan that isn't running when it should. The fans assist in transferring heat from the radiator to the surrounding air, and are most needed when the car is stationary. This doesn't mean that the fan is bad. It could be that the relay is malfunctioning or there is a break in the wiring somewhere, so I would try to rule those ...


5

If the thermostat is stuck open, you would get the symptoms you describe. A thermostat stuck closed will cause overheating.


4

It depends on the vehicle, why it is being left, and how it is prepared before being left. If it's a vehicle that's in reasonably regular use, then I'd recommend making sure it's used at least once every week or so, and is driven far enough for the engine to get up to full operating temperature. Just starting it and letting it run is better than nothing ...


4

bad air duct door You have multiple air duct doors in your car. One of them will control the air from your heater. You may have situation where the servo motor is bad in a particular door. Sometimes you can have a situation where hot air comes out of one vent and cold air comes from another and various combinations of the issue that maps back to a bad ...


3

I had a problem with my VW Golf overheating. I also changed various parts, the thermostat being the first as that controls the circulation of the coolant. In the end I found the cause, the system wasn't pressurising as the o-ring on the filler cap had a kink in it and therefore wasn't making a good seal. I straightened it out and then it worked. Lesson of ...


3

I had a similar problem with my 2000 Ford Focus last year. I can't remember what it was called, but basically it's a thermostat that's sits against your radiator that turns on the radiator fans when not enough air is flowing through the radiator. Like when sitting in traffic. Look for wires running from the radiator to the fans. They sit right between the ...


3

Check the overflow tank on the radiator when the car is overheated. If that tank is full, you've probably got a blown headgasket - that's how I spotted mine. For the thermostat; did you buy an OEM one, or after market? Foresters are very particular about the thermostat, and ONLY the OEM ones work reliably.


3

I would check the water pump, it sounds like the blades may have corroded away. From your description it certainly sounds like the water isn't circulating.


3

I'm in general agreement with Ben. Cooling fan not working. The description of high vehicle speed = okay and low speed not means your fan isn't working for you. This could be a problem with fan controller, fan motor or temp sender used to turn on fan. Note, the fan shrouds matter big! Ensure they are sealed off to radiator correctly. Please check the ...


3

You need to purge your cooling system. Raise the front of the vehicle with a jack or ramps. Driving up a sidewalk works too. With the engine cool (when you touch it it should be cold): Remove the radiator cap. Run the engine. Turn on the heater. Accelerate the engine to 1500-2000RPM. You will see the coolant level go down and/or bubbles. Pour in some new ...


3

If you haven't done this already, check your antifreeze levels of your overflow and radiator when cool. Make sure both are full. Often times, there can be an air lock preventing antifreeze from circulating through the heater core. I normally leave the coolant cap off and jack up the vehicle in the front after starting the vehicle and letting it warm up ...


3

The reason this occurs is to take care of the humidity in the vehicle while your defroster is running. MANY older vehicles have this as a common function when your defroster comes on. It's odd though that the temperature setting doesn't change your AC temp. Chevy's 2011's were all CAN BUS computer controlled systems, it might just be a glitchy computer ...


3

OP Resolved the Issue flow direction was not an issue. OP reconnected hoses and stated the issue is now closed.


3

As far as I understand it, your pollen filter is filthy and should be cleaned or replaced.


3

This hasn't happened with any of the cars I have owned over the last 22 years - which is a pity, because one of the things I would have liked is designed functionality to do what Erik vanDoren mentions - setting the selector between positions to try and get this to happen. In my more recent cars (last 10 years or so) it is impossible to get this to happen ...


2

Air Vent Odor This issue is bacteria in the ventilation system. This is not related to charging the air conditioning system as some have indicated. They are separate systems and you do not get Freon in your cabin by using the air conditioner. The ONLY way to attack the problem IMO, is to; remove the vents from under the dash and clean them out. ...


2

My guess is that the ACC temperature sensor is getting wet, confusing it into thinking the interior is colder than it really is. If you have an "interior temp" reading on your dash, it probably uses the same sensor. See that it shows about 58 when wet and normal temperature when dry. If that's the case... find the sensor! If you don't have a service ...


2

Issue #1: You probably blew the second resistor. Sometimes it just happens. I'd take it back to the place you bought it from and tell them it was defective. Issue #2: It sounds as though your thermostat is stuck open and should be replaced. If coolant is allowed to flow unchecked through the system, you'll only get cold air through your HVAC until the ...


2

One possible explanation is that some coolant is bypassing the thermostat altogether. Depending on the thermostat and seal arrangement, this could happen if the thermostat isn't properly seated in the surrounding seal, or if the seal is compromised and not doing its job properly. It would also explain to some extent why the thermostat seems to work when ...


2

Vent Doors in your HVAC system are not working properly You have various doors in your system to direct air to appropriate places as you change the settings on your dash. When you want air to come out at the floor and you change the setting, a door closes off or opens up appropriately in your system to direct the air to the correct location. The internal ...


2

I'm pretty sure the thermostat is stuck open. The coolant/engine won't heat up fully and you'll get cool coolant through your heater core. In most vehicles (and I'm pretty sure this is how the Dodge Ram's work) the coolant goes from the engine to the heater core directly. If the engine is running cold due to an open thermostat, only cooler coolant will be ...


2

I had a similar issue with one of my cars. The water pump was bad. The impeller was plastic and had cracked, so it wasn't spinning (at least not as much as it should be). Since the water pump is not moving enough coolant, you are not getting enough coolant passing though your heater core to heat the car. While you are sitting, the coolant is not moving ...


2

OK - I see from your comment above that the overflow tank is still full. In most cases, if you have a blown head gasket, you'll be losing coolant. In can go into the main crankcase, in which case your engine oil will show the effects of coolant and oil mixing. The oil dipstick will have a mottled, milky appearance. In can also go into the exhaust system - ...


2

Using the heater has no effect on fuel consumption. Using the heater won't lower the engine temperature because the thermostat will keep the engine temperature constant. It may actually use a tiny bit more gas from the electrical draw because of the blower motor.


2

This feels like a broken blend door. A blend door controls how much air is allowed to flow past the heater core, or past the a/c evaporator. A broken door means that air physically stuck going past the heater core, thereby heating it up. Unfortunately, those doors live inside of the heater box, which usually requires you to rip apart the dash (and then ...


1

No heat in the cabin and an overheating engine after servicing something in the cooling system... My bet is air trapped in the cooling system as it would account for both of the symptoms and matches the timeline of when the issue started. Trapped air would also explain the overheating without coolant loss. If needed I could elaborate on what to do to get ...


1

I was trying to find a picture for you but to no avail. The best thing that I can recommend is have someone turn the mode switch back and forth while you crawl around under the dash and listen for which motor is making noise. This will be external to the heater box. Once you locate the mode control motor, remove it. The motor will have a male shaft ...


1

Some cars have a small electric pump for creating coolant flow around the heater matrix. I don't know if your car has one of these, but if it has, it could be the problem.


1

Is it a gradual change? Like when you turn the speed selector dial, does it slowly get cold? Or does it just literally instantly change? Are there any noises you hear when you change from low to different speeds? This is important. I believe they use HVAC control units in those and that may be causing the problem. There are two motors, one for vent control ...


1

Things to check: Is the engine fan running slowly at idle? If so, its a sign that it needs replacement. Is there a funny smell in the cabin? Refrigerant tends to slowly leak and has a weird smell. Have a friend smell the cabin air in case you got used to the smell (due to driving it all the time). For more and better help we will need a bit more info.



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