uhohitzluke

***woops. made a typo on the title. I meant unsealed.




The cap on my coolant overflow tank cap has cracked off completely. ...I'm pretty sure I drove a fair amount with it like this. Is this safe to do? My car hasn't felt funny or had any other issues. Currently waiting for a new cap to come in through the mail.

fernando.

You're safe.

It's just an access point to be able to add coolant for top up, the rad cap will take care of sealing the system while the car is running.

uhohitzluke

Cool. Thank you, sir! ☺

GSteg

Just make sure the tube stays submerged, otherwise it'll suck air into the system when the cooling system de-pressurizes.

jkelley

This.

That's all that really matters. Tube needs to be submerged in coolant at all times. Often the tank will have a higher level after a drive (operating temp) than before a drive (cold start). So make sure it's submerged when cold.

zeroptzero

The coolant tank isn't really a sealed container, it is relatively sealed but not 100%. When you get a new cap you can dump the fluid in the coolant tank and clean it out prior to filling with new fluid, any dirt would have settled to the bottom of the tank.