Q: Engine idle fluctuates and dies.

asked by on December 06, 2016

When i start my engine i can hear some sort of running water noise. Car starts up fine but when put into drive it will idle below 1 rpm then die out. i also and losing coolant and oil but when i check the oil its not milky and i dont have big tuffts of smoke coming out of my exhaust

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This may be a result of a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. Since this valve is controlled by the vehicle’s computer, it will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed. The loss of coolant may suggest you have a leak somewhere in the cooling system. The fact that the oil is not milky colored and there is no white smoke coming from the exhaust is a good sign that you do not have a blown head gasket. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your idle air control valve.

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