Q: Radiator constantly losing coolant but no leak!

asked by on February 11, 2018

Hello there. I check my radiator coolant level ( I open the radiator cap and check to see if it is full ) about every week. I’ve noticed it keeps getting low on coolant and I have to add a bit to keep it at full although there are no leaks at all! The coolant container storage thing ( beside the radiator cap ) indicates coolant level slightly above low. Is it because of this that the radiator cap constantly gets low on fluid and the coolant goes into the storage tank? Also, can I add a bit of distilled water or windshield washer fluid to the radiator to keep it at full whenever it empties a bit? Or should I use the green coolant? I’m not worried about it freezing because it almost never gets below freezing and there is coolant mixed with it. But is there a problem with adding water or windshield fluid to radiatior cap? Thx

My car has 5000 miles.
My car has an automatic transmission.

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Your vehicle is new and thus still under the manufacturer’s new car warranty. If you believe a defect exists, you should promptly return the car to the dealer and they will investigate and repair the issue as needed at no charge to you. If you add anything other than the manufacturer recommended coolant to the cooling system, you will potentially void the new car warranty. As important, as a technical matter, adding solutions to the radiator, other than the manufacturer recommended coolant can damage cooling system components and metals via corrosion, electrolysis, and chemical conversion and degradation of the coolant. It is very important to use only the exact materials and chemicals specified in the owner’s manual. You certainly have the option of obtaining your own mechanic through YourMechanic, even if you have a warranty. On this particular issue, if you desire that a mechanic from YourMechanic look at it, please request a coolant leak diagnostic. You do have a leak. The level of coolant in the radiator and reserve tank should remain constant without you having to add any make up coolant for at least 6 months of operation, if not longer (water does evaporate from the solution, causing volume to fall, but the system is pretty well sealed). If you request the diagnostic, the responding certified mechanic will get this resolved, right at your location. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.

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