bowles

Hi.

I am looking after my daughters 2010 Mazda 3 (sport) while she is away so I am not that familiar with this car. It struggles to start when the engine has cooled down to outside temperatures of just above (0 Celsius/32 Fahrenheit) or less. Depending on the temperature of the engine it takes between 2 seconds and 6 seconds before it runs smoothly (as opposed to my 1994 Japanese built Honda Civic which is running smoothly on first rotation at the same temperature and even much lower temperatures). If the temp is a bit lower at -1 Celsius the Mazda 3 will stall if I just use the key (I give it 1/4 pedal of gas so it won't stall during the time it struggles to smooth out). Also (when cold and struggling to smooth out) white steam/smoke comes out the exhaust (there seems to be a very small amount of oil smell so it seems that maybe a bit of oil is slipping above the piston on the cylinders that are struggling to start firing). After it has run for 10 minutes and been turned off for 30 to 60 minutes it will start with just the key perfectly (no need to give it extra gas at the pedal and there is zero white steam/smoke). My Mechanic said the sensor is pointing at the emission valve. However he is not sure so he backed off and suggested taking it to Mazda. He is very good with my Honda since he owned my exact model but is much less confident with the Mazda 3. I was reading forums about Mazda 3 cold start problems and it seems it could be 10+ things causing the problem. I am concerned trying things only to get it correct with the last one could cost into the $1,000s. My concern is it may not start at all at -26 Celsius. I am thinking a block heater will not help (warms the wrong parts). I am not an expert (took auto in secondary school, it was the basics, it was 50 years ago). Does anyone have any suggestions for this Mazda 3 problem (what to try in most-likely-to-help sequence). I could take it to my mechanic and that might give him more confidence and we can start trying things.

Thanks,
John

P.S. I started out starting the car once a week and running it to the local mall. It had 1/3rd a tank of gas. After the temperatures dropped and the cold start problem started to occurred I did some reading and I filled the tank right full. I was also reading I should use a gas stabilizer (my mechanic also suggested this). I will be doing this probably tomorrow. The insurance will be taken off mid February so at that point I can only start it and warm it on the driveway. Just before this I have a list of things I will do that I found on the web (levels topped up, etc).