Leaking Coolant Reservoir Symptoms

Here are some obvious signs of a faulty or damaged coolant overflow tank: 

1. Low Coolant Level

A damaged or faulty engine coolant reservoir could result in your coolant level constantly running low. Depending on the severity of the damage, you’ll notice small or large coolant fluid stains under your vehicle. When the coolant level is low, the ECM (Engine Control Module) will log DTC P2560. 

Note: A coolant leak could also happen due to a damaged reservoir cap, radiator hose (also referred to as coolant hose), or radiator filler neck, resulting in a low coolant level.

2. Coolant Odor

If you’ve noticed a sweet smell (like maple syrup) from the front of your vehicle or throughout the cabin, it could be due to a bad overflow reservoir tank. Typically, this indicates a coolant leak within the engine compartment and must be diagnosed soon.

3. Engine Overheating

Bad coolant reservoirs may fail to store the excess coolant or combat the increased pressure, resulting in the engine overheating. You’ll notice the temperature gauge flickering on your dashboard when this happens. 

Besides these faulty reservoir tank symptoms, you could also have an overflowing coolant tank.   

Frequently Asked Questions

What Causes The Coolant Reservoir Tank To Overflow?

Here are some reasons why your engine coolant reservoir could be overflowing:

• Bad radiator cap: A bad radiator cap could release the coolant fluid into the expansion tank too quickly, resulting in a coolant leak in the overflow tank. 

• Faulty head gasket: The head gasket creates a seal between the water and engine oil channels and the combustion chamber. So, you’ll notice a coolant leak if this component is loose or damaged.

• Too much fluid: If there’s excess fluid in the coolant overflow tank, it’ll leave no space for the hot coolant to expand. You’ll notice a leak in the radiator coolant overflow tank when this happens.

• Faulty thermostat valve: A fault in the thermostat housing may prevent the thermostat valve from opening, resulting in the engine overheating. If your engine continues to overheat, it’ll cause your cars coolant reservoir to overflow.

• Malfunctioning water pump: If your water pump is faulty, it may either pump the coolant fluid too slowly through the coolant system or completely prevent the flow. When this happens, you’ll notice the engine overheating and stains of coolant fluid on the ground.

• Worn-out radiator: The radiator is lightweight and tends to wear out quickly. If the radiator is cracked or damaged, it may cause the coolant to overflow.

How Can I Tell if My Coolant Reservoir Is Cracked?

Physical damage such as cracks or splits on the reservoir’s surface, often accompanied by a white or colored residue indicating dried coolant, are signs of a crack.

Is It Safe to Drive with a Leaking Coolant Reservoir?

No, it is not safe. Driving with a leaking coolant reservoir can lead to engine overheating and serious damage. Repairing the leak before extensive driving is advised.