How to Find & Fix a Coolant Leak

By March 24, 2017Troubleshooting

Unfortunately, there’s not enough antifreeze in the world to prevent that from happening. (source: dmvyanks,

Coolant is a necessary liquid in your vehicle. It’s typically a 50/50 mix of water and antifreeze. Coolant prevents both overheating as well as freezing in the cold winter months.

Coolant leaks can be caused by a number of issues, including:

  • cracks or holes in your radiator or heater hose
  • a water pump with a bad shaft seal
  • a damaged heater core
  • a blown head gasket

Some of these are quick and inexpensive to repair (such as a radiator hose), others are more costly (the radiator itself). In any event, if you have a coolant leak, it’s best to get your car into the mechanic ASAP, to avoid your engine overheating.

Click here to learn what to do if your car overheats.

But how do you know if it’s a coolant leak you’re dealing with? There are lots of different types of potential leaks in cars — take a look at our guide on identifying what’s leaking out of your car.

How to Find & Fix a Coolant Leak

Is your car leaking coolant?

Find out by placing some cardboard underneath the front of your car. If you see green or orange liquid with a slimy consistency, you’re probably leaking coolant. (Antifreeze is usually easy to spot because it’s a bright neon green.)

Is your temperature gauge rising?

You’ll see the gauge going up (some cars also have a Low Coolant indicator light). The temp gauge may be an indicator that you’ve blown a head gasket. The head gasket forms a seal between the engine block and the cylinder head, sealing in the internal combustion process and keeping coolant and oil from mixing together as the two fluids travel from the engine block to the cylinder head.

This can be a very expensive repair, so if you think you may have a coolant leak, get it checked out by a trusted mechanic right away.

Is the coolant tank empty?

NOTE: If you’ve been driving an overheated car, wait at least 30 minutes for your car to cool before opening the hood.

Check the owner’s manual for instructions on locating the coolant reservoir. If the tank is empty, you likely have a coolant leak. You can temporarily fill with water, but that’s only a quick fix to get you into the mechanic. Do not attempt to drive your car around with just water in the coolant tank. Even better is to put a 50/50 mix of water and antifreeze in the tank.

Check your radiator.

Again, always be sure your car is cooled down before opening the hood. Check your car’s manual for a diagram of your radiator if you’re unsure where it is. Is there wetness around the radiator, radiator hose or clamps? If your radiator is damaged or badly corroded, then you may need a new radiator, which is a rather expensive repair. If the hoses are leaking, it’s quick, easy, and inexpensive to replace hoses. (Pinch hoses to check for cracks, hardening, or blisters.)

Check your passenger side floor.

If coolant is leaking onto the floor of the front passenger side, it could be a damaged heater core. The heater core is located inside the HVAC unit under your dashboard, so if the heater core (or a hose connected to the heater core is leaking), it could drip out onto the plastic HVAC case and onto your passenger side floor.

How to Fix a Coolant Leak

Fixing a coolant leak obviously depends on where it’s coming from. The first step is getting a proper diagnosis. Call an experienced mechanic like JL Motorworks. It’s important to get in soon so your leak does not cause additional damage (and more costly repairs).

If you know your way around under the hood, you may be able to detect a coolant leak from damaged hoses, and that’s an easy enough repair to do on your own.¬†Consult your car manual and call us with any questions you may have.

JL Motorworks has quick, accurate diagnostics — and we won’t overcharge you or recommend unnecessary repairs. If you’re in the Long Beach or La Habra area, call today!

How to Find & Fix a Coolant Leak | JL Motorworks