Q: Q: Engine idle fluctuates and dies.

asked by on

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

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Q: Engine idle fluctuates and dies.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Inertia switch/Fuel pump

The inertia switch is supposed to totally disable the fuel pump power supply when the vehicle is in an accident or rolls over. You will need to check the power connector into and out of the inertia switch to make...

Q: Is there an adjustment on the oil pressure switch?

There are generally three types of oil pressure sending units. The earlier model vehicles were designed where the switch is mounted in the output side of the oil pump to which a connecting tube is attached. This links up to...

Q: Replaced the IAC on my 04 Xterra now idle surges

Sounds like you have taken a lot of the right steps, but lets go back to the beginning. A P0505 code doesn't necessarily mean the IAC is bad. Specifically it says that there is a malfunction in the idle control...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.