Q: My radiator seems to forcing coolant into the reservoir.

asked by on

I am not losing power, I am not over heating, it is not hard starting. I chance thermostat and it still continue I want's to know if to chance the radiator.

My car has 240000 miles.
My car has a manual transmission.

Hi there:

If your engine is not overheating or showing any signs of cooling system problems, then there are two reasons why additional fluid will show up in the overflow reservoir. First, it’s possible you might have too much coolant inside the cooling system. The second possible reason for this to occur is if the coolant mixture is too thick. As coolant gets hot, it expands; which is why manufacturers recommend a 50 / 50 ratio of coolant to water; so that it doesn’t overflow into the reservoir as often. You might want to flush your radiator and fill it with a 50/50 coolant blend first to see if this solves your issues.

Was this answer helpful?

This is proper operation of the coolant reservoir. It is also known as the expansion tank. As the coolant is warmed by the motor operation, it expands. If there wasn’t some relief in the system, hoses and other parts would eventually burst.

There is an exception to this. If the coolant reservoir has been properly filled to its full mark when the motor is cold, it should not overflow. If it does, then your motor is experiencing an overheating conditions of some sort. There are conditions that can cause the coolant reservoir to over fill but the motor won’t show any obvious signs of overheating to the driver. If this condition exists, it will need to be investigate further. It isn’t an easy thing to make a determination for.

If you still feel you have a problem, I recommend the following inspection to help you out. Car is overheating I chose overheating because a over flowing expansion tank is a precursor to a larger cooling system problem.

Good luck!

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My radiator seems to forcing coolant into the reservoir.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: every two days I'm constantly filling up my coolant resivior because it will get down to min level. car does not get hot temp gaug

You are loosing coolant somewhere. I would have the cooling system pressure tested by a mechanic to see if the cooling system is leaking externally or internally. Once the pressure is put on the system then a leak check can...

Q: Clicking when under load

If there is no noise in reverse, regardless of engine speed while in reverse, then you have eliminated the engine as a source of the noise but implicated the transmission and/or the drive axles. However, engine speed is typically low...

Q: Q: Radiator leak

Hello there! To verify if the radiator is in fact leaking, I would recommend that a well-trained technician performs a pressure test on the cooling system. Pressure testing the system will expose any coolant leaks in the system and make...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.