[janker]

Originally Posted by SD1too

Hello Julian,

My first thought is an air lock. Was the MG Rover refilling/bleeding procedure followed exactly the last time work was carried out on the cooling system? If you are in any doubt drain it completely, including the cylinder block plug, and start from scratch. Don't take any short cuts and note that the bleeding screw is only removed during the initial filling. It must be refitted before starting the engine.
In the summer I visited a member's KV6 with exactly your symptoms and this was all that was required. No parts were purchased.

Idling the engine for an hour is a waste of time. The car must be driven to put the engine under load so that it reaches proper running temperature. According to the IPK diagnostics, is it staying within the range 92 to 100˚ (when the low speed fan should start and lower it)?

Is the expansion tank filled no higher than the internal 'MAX' marker? A common mistake is that owners fill to the top of the fins.

Simon

Hi Simon Im going to drain everything completely and refill again using the procedure, When i fitted the Kaiser stat setup i didnt realise the stat that was in it is only 80 / 82 degrees so it has never got up as high as 92 to 100 , I have made sure tank is just filled to internal max limit but will try a complete system refill and let you know, One thing i have noticed is i havent seen water entering through the small pipe back into the header tank when engine running ?