Engine Cooling problem
1993 Ford Telstar 6 cyl Front Wheel Drive Manual 180000 miles

Hi all

I have a ford telstar tx5 - 6 cylinder. Lately (after 5 minutes of driving the fan comes on and the temp indicator goes over hot.) If I keep driving (after about ten minutes the needle drops down to middle and the engine makes a wierd noise. After 5 mins the temp indicator light goes to hot again and the fan comes on. At all times the radiator is full with coolant. Throughout all this there doesn't seem to be any degradation in engine performance

Thanks