I have a 99 Audi a6 quattro and it just started running hot all of a sudden..I had a fan that wasn't running got that fixed been consistently putting coolant in it ant that doesn't help it goes all the way to the H so what could be the problem please help!!!
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It could have air in the coolant system if it got hot and puked a bit of coolant out while the fan wasn't working. There should be some bleeder valves in the heater hoses where they meet the firewall. If you don't have all the air out of it, it will run hot and continue to puke coolant out the overflow.