Car will not idle.

ANSWER : 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. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your idle air control valve.

ANSWER : Hi there. This can be caused by the issues that you mentioned or a number of other things. You need to make sure all of the connectors are making good contact. I would then need to know what codes are in the computer to know if this is a circuit issue or not. Most of the time, it is not the circuit but instead a vacuum leak.

If there is a vacuum leak, then the vehicle will act like this and the computer cannot control the idle. Most of the time it is a bad hose or an EGR valve that is stuck open. That is the most common cause for this. I typically remove the EGR to check it to feel the diaphragm on the bottom of it to see if it is moving correctly. If you need to have this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair your car’s idling issue.

ANSWER : Hi there. What had happened is the wrong key set the security to the vehicle. This is to prevent the vehicle from starting with the wrong keys. Try removing the battery cables (+) and (-) for 13 minutes. During that time, put the original key in the ignition and turn it on. Activate everything in the car even though there is no power. Then remove the key and hook up the battery cables. The computer should have reset and reset the security. If the security is still being tripped, then I recommend seeking out a professional, such as one from Your Mechanic, to help you

ANSWER : The idle air control valve is common for causing a rough idle in many cars, but it sounds like you have already corrected that. Another thing you may also want to check is the crankshaft position sensor. A crankshaft position sensor monitors the position or rotational speed of the crankshaft. This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters. When this is faulty or not working properly, this will cause problems with the ignition system and generating spark transmission to the spark plugs resulting in starting problems, rough idling and other performance issues. You may also want to check the fuel pressure as low fuel pressure can also cause rough or poor idling if the fuel pattern being sprayed from the injectors is not consistent. This can also happen in the case of having dirty fuel injectors which may also interrupt the spray pattern of the injectors. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your car.

ANSWER : Hello – your symptoms suggest worn piston rings or valve stem seals (smoking), and a possible air leak in the intake, or idle air control valve sticking open (high idle). Both are signs of a higher-mileage engine with significant wear. I recommend an engine inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

ANSWER : There are reports that the replacement alternators will not communicate with the engine computer and will not charge correctly. I recommend using only the manufacturer approved replacement part. It can be new or remanufactured but approved for use in the vehicle. Some lower cost alternators on the aftermarket will have charging problems since they will not communicate with the ECM on the vehicle and will stop charging.

ANSWER : It is very possible that you have a valve cover gasket or spark plug tube seal leak on your vehicle. These type of leaks will allow oil to leak onto the spark plugs causing misfires. When the engine misfires due to oil getting on the spark plug, the engine oil will burn. Since oil and tires are both petroleum products, they will both smell similar when they are burning. I would recommend having an oil leak inspection performed by a qualified professional to determine if there is an oil leak. Consider YourMechanic as an Oil/Fluid leak inspection can be peformed at your home or office.

ANSWER : It sounds like you may have a faulty electronic throttle control unit. The electronic throttle unit opens and closes the throttle blade based upon input from various engine control sensors, including the accelerator pedal. This unit also controls, among other things, the cruise control function as well. When this control unit fails, this may cause intermittent stalling issues and rough idle problems. This is usually repaired by removing and replacing the throtte control unit. I would suggest having an expert from YourMechanic come to your location to diagnose and inspect your vehicle at your earliest convenience.