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Q: After a 356 mile commute, my car overheated and anti-freeze was all over my engine and under the hood. No apparent leaks.

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This is the first time this has happened. Is it possible that it is just a bad radiator cap? What else can it be ? What do you suggest I do? There are no apparent leaks and my reservoir was basically full before my trip. Now, it was empty but remains full as I poured more into the reservoir. Only heats up as I press on the gas.

My car has 100000 miles.
My car has a manual transmission.

Hello, thanks for writing in. I’d be happy to provide my insight.

It may be possible that a bad cap was the cause of the coolant under your engine. Radiator caps are designed to hold a specific pressure that is generated by the cooling system as it comes to operating temperature. The temperature rises the cooling system pressure, so therefore the pressure on the cap also rises. A weak or worn out cap may not be able to hold the cooling system pressure, which may result in a leak. I would refill the system, purge it properly, and then see if the issue persists or the leak reveals itself.

If you would like help with inspecting your radiator cap or need your car inspected, consider having an expert automotive technician from YourMechanic come to your home or office to perform an inspection or repair for you.

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