Q: Leaking radiator cap

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I noticed my car engine smoking from the front, when I checked I saw that coolant had been leaking from the cap then down the back face of the radiator causing the smoke I'm assuming. My overflow tank had been drained down to the minimum line so I refilled it and a few days later it was empty again. My car only starts smoking when the overflow is filled and stops when its near empty. My temperature gauge on my dashboard has not gone past half way where it always goes up to so I;m assuming my car is not over heating. I just want to know why that is happening and what to do to fix it.

My car has 225000 miles.
My car has an automatic transmission.

Hello there:

Most of the time, the smoke you see coming from the front of the vehicle that has a coolant leak from the radiator cap is steam. This is an indicator that the radiator cap needs to be replaced; as it’s not maintaining a solid vacuum; which could eventually cause air bubbles to be trapped in the coolant lines and eventually overheat the Toyota. If the overflow reservoir is draining, it’s because it’s trying to fill the evaporating coolant caused by the radiator cap in this instance most likely. If you replace the radiator cap first and this doesn’t solve your issue, contact one of our professional mobile mechanics to complete a car is leaking coolant inspection.

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