Q: Where is my coolant going? My car keeps overheating and blowing cold air. The temperature rises when stopped and drops when accelerating.

asked by on March 12, 2017

my car keeps over heating. the coolant reservoir and radiator have been bled and filled twice within the last two days and when I checked the reservoir this morning it was down to almost nothing. the temperature will rise when I am stopped, at a red light lets say. and blow freezing cold air and as soon as I accelerate to about 50kph, the warm air will start blowing through and the temperature gauge will go back to normal (about a 25% of the gauge, red being 100%). it has been brought to 2 mechanics so far and neither of them can figure out the problem. could it be a faulty hose? or worst case scenario, my head gasket?

My car has 223 miles.
My car has an automatic transmission.

Car is overheating Inspection $79.99 - $99.99 Get a Quote

Look everywhere around the engine and see if there is a split hose or loose hose clamp. If the hoses and clamps are in good shape and tight, then check the core plugs (freeze plugs) and see if there is any residue that indicates a leak. If there is no residue or core plug leak, then take the dipstick out of the engine and see if the oil is milky or not. If the oil is milky, then a head gasket is burned and water is getting pushed into the oil system. If the oil is normal color, then the cooling fans may not be working properly and causing the coolant to boil out of the overflow tubes. This would explain why the vehicle overheats when sitting but runs cool when in motion. Check the fans to see if they are working. If the fans are not coming on, then the fan motor relay, fuse, or motor could be all burned out making the fans not work. If you need further assistance with your engine overheating at a stationary position, then seek out a professional, such as one from Your Mechanic, to help you.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

Can driving in heavy rain warp rotors?

Hi There, Driving in heavy rains should not impact the rotors as they are designed to withstand water. In some cases, in the event they are subjected to water continuously and develop severe rust this may be possible, but that...

I want it to be louder

If louder is your thing, you should talk to someone at a local exhaust shop. I bet they'll have some aftermarket exhaust options for you. Just keep in mind, you may be meeting more of your local law enforcement folks,...

I got 2 codes P0304 and p0102

Hi there: The OBD-II trouble code P-0304 indicates that cylinder four is misfiring or having ignition issues. The most common causes include a faulty spark plug, clogged fuel injectors, or even an intake valve leak. To know for certain, you...

What does the antilock brake system (ABS) Warning Light mean in a 2012 Chevrolet Equinox?

The antilock brake system (ABS) Warning Light is located on your instrument control panel. This alert illuminates when there is a problem with your ABS system, which is a key component in your brake system. However, sometimes the ABS Warning...

What if my car shakes and it's not the tires what else can cause the shaking?

If the tire/wheel balancing and run-out (side to side motion) have been checked and ruled out, the fault may be suspension or driveline related. Worn inner c/v joints for example, can cause a vibration while accelerating either from a stop...

08 impala has engine power reduced light on. Car starts

Hello, Unfortunately, this is a common issue in many Impalas. This can happen when the catalytic converter is clogged or has also been known to happen when the traction control system has encountered an error. This light comes on as...

My car is jerking and has reduced engine power

Hello and thank you for contacting YourMechanic. Your vehicle may have a clogged catalytic converter or muffler. This message displays if the back pressure on the engine is too high. Start the engine and get something to block the...

Transmission stuck in gear in Drive 2007 Chevrolet Silverado 2500

Hi there - it's possible that your problem source is the torque converter lockup clutch NOT releasing as the truck slows down. This would lug the engine as though it's in top gear until vibration, or an engine stop/start sequence...

99 mercury cougar with a 4 cylinder leaking antifreeze from the overflow hose but car is not over heating could it possibly be the

The first thing you should have done is to have the reservoir pressure cap checked to see if it is able to hold pressure specified on the cap. If the cap cannot hold pressure then it will leak out of...

Related articles

Are There Upgrades to Stock Car Hoses?
############Barry Blackburn / Shutterstock.com A wide range of hoses are used on your car to carry everything from engine coolant to gasoline and brake fluid. Most stock hoses on your car are made from rubber – it’s...
How Often Should Hoses Be Replaced?
Your Your engine needs coolant, the power steering rack needs fluid, and the calipers need fluid to squeeze the rotors to stop the car. Most fluids make their way to their destination through hoses. Those hoses are generally made of...
What Is the Difference Between the Upper and Lower Radiator Hose?
Your Your radiator is an essential part of your automobile. It does more than just hold the bulk of the car’s coolant, though. It’s actually responsible for removing excess heat from the coolant before it is sent back to the...