robbos freo

same thing again .drove for 20 mins. in 40 degree heat no problem. 40 mins. later drove home ran like chaff cutter under 2600 revs can,t find source of noise in front checking gear box oil levels tommorow.

Welcome Robbo, further to your PM, 2001 1.8 petrol overheating, noise at the rear of the engine.
What parts have you checked? The water pump is at the back of the engine (drivers side)

re cat converter: robbo again im from aus.and have found that by disconnecting oygen sensor car will run seems to be in fault mode. what is a cat pipe as iwas thinking of removing cat until summer finishes.still 40 degrees plus fan not kicking in till engine very hot using air con to switch cooling fans on water pump fine can i manually over ride temp sesor for fan by installing by pass switch

The deCAT is a straight through pipe for more power. You can hollow out the existing CAT, but either way you need the MIL eliminator. Some people have reported that when you tie the sensor up to the outside of the exhaust it should run fine. The place to ask for one is in the Aus section at MG - Rover.Org -||- The ultimate site for MG and Rover enthusiasts! the deCAT you need and eliminator is the same as the MG TF.
Re. overheating, when the engine is warming up, remove the brown connector at the front of the engine LHS. If fan comes on then your wiring is ok. reconnect. What type of stat is in place.