How to Find the Source of a Coolant Leak Faster and More Accurately

Coolant is vital to your engine. A mixture of coolant and water circulates through the engine to absorb heat. The water pump circulates it in a loop past the thermostat, through coolant hoses, to the radiator to be cooled by air movement and then takes it back through the engine. If your engine runs low or is completely out of coolant, the overheating that results can cause irreparable damage to your engine.

Always check the coolant each time you check your the oil level in your car. If you’ve started to notice the level dropping between check- ups, it’s time to find out where the leak is occurring. If there is a coolant leak, you may see a puddle under the car or start noticing a sweet smell coming from the engine compartment after a drive.

Part 1 of 1: Find the source of the coolant leak

Materials Needed

Step 1: Do a visual check of the radiator, hoses and around the engine. Your vehicle has an upper and lower radiator hose, heater hoses at the back of the engine connecting to the heater core, and probably a couple of other smaller hoses going to the intake manifold or throttle body area. If a visual inspection reveals nothing, move on to the tried and true method of using a pressure tester.

Step 2: Use a pressure tester. Attach the pressure tester in place of the radiator cap.

  • Tip: If you don’t have a pressure tester or want to purchase one, some chain auto part stores offer tool rentals.

  • Note: The radiator cap will have a pressure rating on it. When you apply pressure with the pressure tester, be sure not to exceed that pressure on the dial. Always apply pressure to the cooling system with the engine off.

Step 3: Check again for a leak. Once pressurized, do a visual check around the engine bay once again. Be sure to check all the hoses, radiator itself, and all the coolant hoses and temperature sensors on or around the intake manifold. You most likely will find the source of your leak now.

If you are not comfortable with performing this check on your own, you can get your coolant leak inspected by a certified professional from YourMechanic.


Next Step

Schedule Coolant is leaking Inspection

The most popular service booked by readers of this article is Coolant is leaking Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

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Recent Coolant is leaking Inspection reviews

Excellent Rating

(1,391)

Rating Summary
1,297
41
5
11
37
1,297
41
5
11
37

William

26 years of experience
65 reviews
William
26 years of experience
Infiniti G37 - Coolant is leaking - Leander, Texas
Bill arrived on time and addressed the issue rather quickly. Very pleased with his service! Thanks!
Mercedes-Benz C250 - Coolant is leaking - Austin, Texas
Bill was on time and very friendly. He definitely knew what he was doing - he found the leak in 10 mins

Juan

12 years of experience
29 reviews
Juan
12 years of experience
Honda Civic - Coolant is leaking Inspection - Suisun City, California
Jain was on time and worked hard looking for the leak. I scheduled him for Tuesday morning to come out and replace the thermostat

David

10 years of experience
155 reviews
David
10 years of experience
Pontiac Grand Prix - Coolant is leaking - Orlando, Florida
Man this guy is awesome like I said all along if something is wrong with my vehicle am calling david.

Adam

17 years of experience
88 reviews
Adam
17 years of experience
Jaguar Vanden Plas - Coolant is leaking - Boca Raton, Florida
Adam found the said leak which derived from a crack in the plastic holder of the coolant expansion tank. I would hereby like to say that he is super competent and has great knowledge of my vehicle and along with his pleasant personality, he certainly serves Your Mechanic in good stead. I would definitely recommend him to anyone who is seeking the services of a great mechanic. Milton Adams

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