[andratxpeter]

I run a 1992 968 cabriolet and generally all is good. Yet when I start up from cold, once the engine has warmed up, the heater pumps out really hot air and a few minutes later the sensor screams out "Enough!" and chilled air pumps in until the sensor screams out again and hot air starts - after 15 minutes or so of fluctuating the temperature balances out and I get the internal temperature I want. When the car is hot and I re-start then the whole thing happens again but for a far shorter time - maybe 3-4 minutes. Wait for it...................some days it works fine but those days are becoming rarer!! Could this be the internal temperature sensor slowly failing? If so where does this fellow live? Any thoughts please -Thanks Peter

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[flash]

pretty sure you have a vacuum leak in the heater control circuit. it is likely at the heater control valve, which defaults to "on" when there is a leak. carefully check the vacuum hoses and connections in that circuit for any signs of cracking.

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