I have a 1997 chevy Malibu. The car runs very good during the summer months, however when the temperature drops below 50 degrees the car wont start. When it warms up to 60 degrees it will start with n

Check the fuel pressure because I have changed many fuel pumps on 1997-2003 Malibus.

battery is too low rating for car to start in winter. Or battery has bad cell and will hold a full charge needed to start, or the alternator is not putting out a full charge to the battery .......

CHECK THE THERMOSTAT. THERMOSTAT IS THE ONE THAT SENSE THE ENGINE TEMPERATURE AND TURNS ON COOLING FAN WHEN THE ENGINE IS HOT.

Somewhere along the electronic side you have a faulty component thats failing when the temperature drops ,what it is and where it is i have no idea at all it could be in the computer ,in a module somewhere and as iam a europeon mechanic whos never seen this model before i just cannot tell you were to look first .The fault though iam familiar with as had this on more than one occasion and older cars it was the ignition module but this is incorperated into the ECU on more modern motors .

I would get your engine temperature sensor checked out, this tells the E.C.U how much fuel to supply to injectors, (if a deisel then check operation of glow plugs )

Does the engine temperature climb too high? She may need the radiator core blown out with compressed air from the inside to get rid of the bugs and other debris. Does the anti-freeze look clean or rusty? Flush and clean the system if it looks rusty--fill with fresh 50/50 water/anti-freeze. Check the action of the cooling fan(s). They should turn freely by hand when cold. Check the fuel pump pressure and replace the fuel filter. Does the check engine light come on? The O2 sensor(s) may be getting tired. Replace if a lot of miles on it (them).

Check and load test battery. If good, use a volt meter across both terminals.. when.cranking, volts should not drop below 9.5. If it does, replace starter. No valid starter test can be done unless battery has been proven to be good.

P0128 - Coolant Thermostat Below Thermostat Regulating Temperature
REPLACE THE THERMOSTAT THE ENGINE IS NOT REACHING CORRECT OPERATING TEMPERATURE, 190-195 DEGREE'S FAHRENHEIT.

your radiator could be getting stopped up. also water pump could be weak. during summer though you have electric fans that should be working. need to check. you can purchase some stuff called water wetter by redline racing oil that will drop water temp 20 degrees which is substantial when a thermostat is usually 180 to 190 and boiling is 212.

Check the following things: air filter, wheel alignment, and timing belt, all of them if not serviced on time can affect your fuel consumption. I do not think its the heat because I drive my car in Phoenix AZ with temperatures comparable to Dubai and I still get 500+ km/tank.

Good Luck,

Alex (Civic 2003 1.7 manual)