I have a civic 2005 vti manual petrol driven. Been with us for 4 years. Lately, I have witnessed some problem in the car. The rpm of the car used to be within 800-900 on a fully warmed up engine. But now the rpm has become a bit unstable and reaches 1100. Moreover, I had also noticed that the car is not reaching its operating temperature and the fan also keeps turning on frequently. I did replace the thermostat valve but still to no advantage. Earlier back, a dead cold engine used to reach the optimum temperature within 5 minutes of idle startup.
Experts please help. As a result of all this, my fuel economy has badly deteriorated