Q: Coolant issue - 2008 Honda Accord

asked by on

Hi, so previously my car overheated and I found out that my reservoir was empty. I filled it up and next day it was empty again so I figured I would just purchase another which I did from auto zone. I switched the reservoirs and then I allowed my car to sit for a few hours.. Then when I came to my car to check.. The new reservoir was empty.. Is there another problem here? I'm really confused

My car has 111091 miles.

Hello. When a car is low on coolant, even if you refill both the radiator and the reservoir, air can still be trapped in the system. After you run the car for a while, the trapped air is expelled and then the resulting "vacuum" causes coolant to be drawn from the recovery reservoir back into the radiator.

That might make it appear as if you are loosing coolant or have a reservoir leak, when in fact all that is happening is the system is just normalizing itself. So the reservoir might not have been leaking in the first instance. At this point, if the level of coolant is still falling in the reservoir top off the coolant as this occurs over several days.

At the end of that period, the level in the reservoir should remain steady (you have to judge the level when the car is either hot or cold; the level will vary significantly depending on temperature, so always check cold, first thing in the morning to be able to really accurately judge what is going on with the level in the reservoir).

The point is after a week of "topping off" and/or monitoring the reservoir level, if the level does not stabilize, then you have a leak. Coolant leaks are of two types: external and internal. External leaks are no problem and YourMechanic can identify those via simple pressure testing. Internal leaks through a head gasket are a mini nightmare though. Hopefully, your past overheating experience did not damage the head gasket on the engine, causing an internal coolant leak. If so, the head has to be removed from the engine, checked to make sure neither it nor the block are warped and a new gasket carefully applied in the auto mechanic’s version of "clean room" conditions. If you cannot get the coolant level to stabilize, YourMechanic will find the leak for you and then explain the least costly and most efficient options to get it resolved.

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. Coolant issue - 2008 Honda Accord

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: Can I add water or fluid to the reservoir till I can get a flush and fill?

Yes, you can, and should, add coolant to the reservoir to make sure the engine cooling system does not run low. Add only a 50-50 (water-antifreeze ratio) coolant mix to the overflow tank, particularly if it is winter season. If...

Q: A/c controls go in and out and now when i turn the car off and take the keys out, the lights are still on. Honda accord 2000.

Hi there: Most of the time, this issue is caused by an electrical relay that has been damaged. It's possible that during your radio swap, this may have caused an electrical issue with your AC system. However, it's also possible...

Q: Q: coolant leak

Engine coolant leaks at the rear, near the firewall, could be due to a failed hose, water pump, thermostat housing, block drain plug, and so forth. The origin of external leaks can be pinpointed by simple pressure testing of the...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...