Following recent overheating problems (not due to coolant loss) on my 07 Octy 1.9TDI on 265K miles, have replaced header tank (with in-built coolant level sensor), radiator, water pump, and finally thermostat (not housing as well).  Now no overheating problems if I run without a thermostat in but, put one in (genuine Skoda part - expensive - ouch) and back to same old overheating problems as if stat was staying closed!  

 

Someone suggested to me that I might need to change the housing itself but can't understand why or how this would make a difference as the stat and housing appear to be two separate parts.  Anyone experienced a similar problem, and come up with a solution? Help/guidance would be appreciated - winter weather approaches and I've no reliable heater!

You say overheating, how long has this been going on for as you may well have a blown head gasket.

 

Does the system get rid of the air in it through the expansion bottle ok as trapped air in the system will cause overheating too. If you wanted to you could run the engine and leave the expansion bottle cap off and see if it overheats then as the system won't be pressurised, if it doesn't, more than likely the head gasket has gone pal.

 

 

 

Steve

Thanks for your advice steveo82 - ran tests as you described and yes, having exhausted all other possibilities, 'tis a blown head gasket.  I've been getting near the point of changing car, so now seems as good a time as any!

No worries and if you change the car hope you find a good one :-)