coolant reservoir melted - cause or effect?
 

My '95 A6 Avant had major electrical disfunction on Friday - like a sticky ignition switch/key barrel - cutting out/restarting on its own, even ran with key out of car. Left it switched off (so I thought) at roadside. Came back 6 hours later, no car. Was then told it went up in smoke and fire dept had it towed away.

Got car back today, 1st thing I see is no coolant and a hole just underneath the tank - signs of melting plastic. Now I guess there was no real fire, but major overheating/smoking.

I know I am probably facing head gasket failure/warped heads, but my question is re. the tank - I only fitted it a few months back (aftermarket brand, not top quality = Topran). Do/can they melt and then cause coolant loss? Or is it a leak/problem elsewhere which then in turn damages the tank?

Note that in '95 a bad ignition switch could cause power to the starter motor while driving causing it to quickly overheat and burn out. I do not remember if the starter is on the driver's side for the V6 but is it is that could have been the cause of the melted tank.

thanks and good call - ignition is definitely 'hot' when battery is connected so starter could well have overheated. coolant tank shows signs of warping as if it's been heated directly so guess probably that which caused coolant loss...damn..