Symptoms of a Bad or Failing Radiator

The radiator’s job is to keep the engine from overheating. The engine produces heat while it is running. Coolant absorbs this heat, then passes it through the radiator where it is cooled off. The coolant is then circulated back to the engine. The radiator is the main component of the cooling system, so it is important that it is in good working condition. If you suspect your radiator is going bad, watch for the following symptoms:

1. Leaking coolant onto the floor

The coolant flows through the radiator, so if there is a leak in the radiator, coolant will leak onto the floor underneath the vehicle. It may be while you are driving or while your vehicle is parked. To positively identify if you have a leak or crack in your radiator, the professionals at YourMechanic will need to do a pressure test to verify the radiator is the cause. During this test the radiator is pressured and colored dye is added to the cooling system, and if it leaks out then you may need to have your radiator replaced.

2. Vehicle overheats

If your vehicle is constantly overheating, the radiator may be going bad. One of the most common failures in the vehicles that overheat is a failing radiator since it is the only way engine coolant is cooled. It may not be to the point where it has completely failed, so the issue should be addressed immediately. If this problem is left unattended, then the engine will continue to overheat and cause the vehicle to break down. When this happens, the repair will be much more extensive, so it is a good idea to address the issue as soon as the vehicle starts to overheat.

3. Sludge in the radiator

The coolant in your vehicle should be yellow or green or red normally. As the radiator goes bad, contaminants discolor the fluid making it a rusty or oil color. This turns into sludge and the fluid will not be able to cool the engine efficiently because it will not drain properly and remain in the radiator. This can be from a failing radiator for vehicles that contain a transmission cooler inside the radiator. The barrier between the coolant and transmission fluid fails and the fluids mix. If you or a mechanic notice sludge in your radiator, it will need to be replaced as it can cause extensive damage to the engine and transmission.

4. Low coolant

If your low coolant light comes on or you are constantly refilling your coolant tank, there may be a leak in the radiator. Do not just keep refilling your coolant, take your vehicle to have it properly diagnosed.

As soon as you notice leaking coolant, your vehicle keeps overheating, you have low coolant, or sludge in your radiator, contact a mechanic to make repairs to your cooling system. YourMechanic makes getting repairs to your radiator easy by coming to your home or office to diagnose or fix issues. You can book a service online 24/7. YourMechanic’s qualified Technicians are also available for any questions that may arise.


Next Step

Schedule Vehicle Engine Cooling Inspection

The most popular service booked by readers of this article is Vehicle Engine Cooling 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

SEE PRICING & SCHEDULING

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

Recent Vehicle Engine Cooling Inspection reviews

Excellent Rating

(191,118)

Rating Summary
179,680
6,078
1,268
920
3,172
179,680
6,078
1,268
920
3,172

Glenn

22 years of experience
38 reviews
Glenn
22 years of experience
Pontiac Grand Prix V6-3.8L Turbo - Vehicle Engine Cooling Inspection - Indianapolis, Indiana
Ok

William

35 years of experience
731 reviews
William
35 years of experience
Mazda 3 L4-2.0L - Vehicle Engine Cooling Inspection - Phoenix, Arizona
Earlier than expected! Diagnosed car within an hour and had an estimate for repairs quick

Michael

28 years of experience
672 reviews
Michael
28 years of experience
Toyota Matrix L4-1.8L - Oil Change - Tempe, Arizona

Eilyas

12 years of experience
17 reviews
Eilyas
12 years of experience
Mitsubishi Outlander V6-3.0L - Coolant Temperature Switch (Sensor) - Marina, California
Very thorough and informative! Eilyas is a real pro and knows his stuff. Your Mechanic is lucky to have him. My problem is fixed & he explained why my brakes were squeaking -- they didn't need to be replaced yet. True honesty and integrity is hard to find.

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How Long Does an Oil Pan Last?
The The oil that is contained in your engine is helps to lubricate all of the moving parts that your motor has. Making sure that the oil stays at the right levels should be one of the top concerns that...
How Long Does a Valve Cover Gasket Last?
Among Among the most important parts of any engine is the oil that is contained within it. There are a variety of moving parts that depend on the oil for lubrication. The valve cover goes on top of the engine...
How to Replace a Condenser Fan Relay
A condenser fan relay operates the fan that removes heat from the engine. If faulty, it will not allow the A/C to blow cool air or function at all.

Related questions

How much is it to replace the rear main seal on a 2007 Hummer H3
Hello. It is common for the rear main seal to leak on this engine. Over time the seal fails and this occurs. You will need to take this to a shop that can remove the transmission to change the seal...
coolant replacement
Hello. The radiator cap for your particular vehicle can be purchased a part store like Advanced Auto or AutoZone. The radiator cap should cost about 8 to 15 dollars. The Duralast and Dorman radiator cap listed at AutoZone should fit...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com