Skip the auto shop - Our mechanics make house calls

Symptoms of a Bad or Failing Coolant Reservoir

coolant reservoir

The coolant reservoir is the plastic reservoir mounted in the engine bay that stores the coolant for the engine. Coolant reservoirs are required because engines go through cycles of expelling and absorbing coolant as they warm up and cool down. When the engine is cold, the pressure of the cooling system is low and more coolant is required, and when the engine is warm the pressure of the cooling system is increased and therefore less coolant is required.

For some vehicles, the coolant reservoir is an integral part of the system, and since it is also pressurized, the coolant reservoir becomes an even more important component to engine safety. Because the coolant reservoir is part of the cooling system, when it has any issues it can quickly lead to issues with the engine. Usually a bad or failing coolant reservoir will produce a few symptoms that can alert the driver that a problem has occurred and should be serviced.

1. Constantly low on coolant

One of the first symptoms commonly associated with a bad or failing coolant reservoir is the need to constantly add coolant. If the reservoir cracks or develops any small leaks it can cause the coolant it is storing to leak or evaporate at a slow rate. The leaks may be small enough that they may not be obvious to the driver, however, over time they will cause the reservoir to empty out. The constant need to add coolant can also be caused by a leak somewhere else on the engine so a proper diagnosis is recommended.

2. Coolant leaks

Another symptom of a potential problem with the coolant reservoir is coolant leaks. If the coolant reservoir cracks or breaks due to old age or overheating it will leak. Small leaks may produce steam and drips, while larger leaks will produce streams and puddles, as well as an obvious coolant odor.

3. Engine overheating

Another more serious symptom of a bad or failing coolant reservoir is the engine overheating. If the coolant reservoir has any issue that prevents it from properly holding coolant, or from properly pressurizing the system it may cause the engine to overheat. Any issue that causes engine overheating should be addressed as soon as possible in order to prevent any possible damage to the engine.

The coolant reservoir is a simple but important component of the cooling system, and when it has issues it can quickly lead to overheating and even engine damage. For this reason, if you suspect that your coolant recovery reservoir may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic. They will be able to determine if the car needs a coolant reservoir replacement.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

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

More related articles

P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed Related Trouble Codes: P2441: EVAP Vent Valve Stuck Open EVAP trouble...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...


Related questions

Q: Advice on cooler additives

Some of it is "snake" oil (that doesn't work) and some of it works to some extent. Realize that the best cooling is water. Water has specific heat and cooling. So water actually cools better than antifreeze. But of...

Q: water not coming to the rediator, can it be a blown casket, peugeot diesel

Hello. If water is not flowing or going into the radiator then it may be possible that there is an issue with the cooling system. If water is not flowing then that may be a sign that the water pump...

Q: Car overheated, now it won't start after cooling it down and putting more water in

Hey there. There are many things that can happen when your engine overheats. The worst of which is a blown cylinder head gasket. When this happens, the gasket between the cylinder and the engine block becomes compromised allowing engine oil...