Hi Have '92 1.4 Astra F NZ engine banger which has a stuck open thermo (runs v cool). It's getting cold and heating sucks. Performance prob not helped either. Replacement (in Haynes) seems a big job for an unhealthy novice. How about putting a Renault 5 'in top hose' thermo in as a work-round? It's secured by a jubilee clip! Any likely probs? Opening temp. differences not too much of a problem? Strikes horror in the hearts of the purists I know. Mr Lazy signing off.