Left in to my 3rd mechanic he said what you said yesterday the heat sensor as it thinks engine is warm fingers crossed he can solve the problem its getting to me
If it turns out to be the temperature sensor and a new one is hard to get and/ or expensive you could do what I did with an old Laguna. I picked one up v. cheap as it ran like a bag of nails once warm, and it was due to dodgy temp. sensor. Rather that spend about the same again (seriously, we're talking Renault prices!) I just wired in a potentiometer (volume control) I had lying around (5KΩ I think it was) and used it like a manual choke (remember them?), worked a treat & it even passed an MOT with flying colours