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What Are the Symptoms of a Bad EGR Valve?

What Are the Symptoms of a Bad EGR Valve? Exhaust gas recirculation systems aren't exactly the most glamorous systems in the average car, but they do perform several very important jobs. An EGR might not help you get where you're going any faster or looking any better, but a working one will get you there a good deal cleaner and cheaper. Symptoms An EGR valve works by recirculating used exhaust gases into your engine. These gases contain unburned fuel but very little oxygen, and they're very hot. A hot intake charge carries less oxygen, so a working EGR system effectively makes your engine act smaller than it really is. In terms of driving, an EGR valve that's stuck open will cause a noticeable drop in horsepower at the very least. Along with that may come detonation -- "knock" or "ping" -- under hard acceleration, and the attendant cylinder misfires. The engine will also see an open EGR valve as a massive vacuum leak, so expect hard starting...

How to Check an EGR

How to Check an EGR EGR valves in a car regulate combustion temperatures within the engine of a car. The valve recycles exhaust back into your car, which makes the car more energy efficient and reduces the amount it pollutes. A faulty EGR valve will result in either a clicking sound in the engine or an engine stall while it is idling. Luckily for car owners, the EGR valve is very easy to check, and you do not need extensive auto-mechanic knowledge in order to perform a thorough inspection of your EGR valve. Things You'll Need Owner's manual Instructions Turn the ignition on in your car, and leave the car in park. The engine should be allowed to warm up for several minutes before you inspect the EGR valve. Pop open the front hood of the car. Locate the EGR valve by consulting your car's owner's manual. The location of the valve will differ according to vehicle make and model. Observe the EGR valve while someone revs the engine. If th...

What Are the Symptoms of a Bad EGR Valve?

What Are the Symptoms of a Bad EGR Valve? Exhaust gas recirculation systems aren't exactly the most glamorous systems in the average car, but they do perform several very important jobs. An EGR might not help you get where you're going any faster or looking any better, but a working one will get you there a good deal cleaner and cheaper. Symptoms An EGR valve works by recirculating used exhaust gases into your engine. These gases contain unburned fuel but very little oxygen, and they're very hot. A hot intake charge carries less oxygen, so a working EGR system effectively makes your engine act smaller than it really is. In terms of driving, an EGR valve that's stuck open will cause a noticeable drop in horsepower at the very least. Along with that may come detonation -- "knock" or "ping" -- under hard acceleration, and the attendant cylinder misfires. The engine will also see an open EGR valve as a massive vacuum leak, so expect hard start...

Signs of a Bad Idle Air Control Valve

Signs of a Bad Idle Air Control Valve An idle air control valve is, in a very real way, the predecessor to the drive-by-wire throttle systems commonly employed today. It performs much the same function as any electronic throttle: to control the amount of air going into the engine so the computer can match it with the right amount of fuel. The only difference between these two systems is that an IAC is smaller and only works at idle. Common Problem Because an IAC valve controls air going into the engine only when the throttle is shut or almost shut, these are the only two times you're likely to notice it malfunctioning. The most common type of failure results from clogging of the IAC valve with carbon, dirt and debris, which restricts the amount of air going through and slows the valve's response time. Classic Symptoms Classic symptoms of a clogged IAC are a rough or unsteady idle, and stalling if the valve passage gets too clogged or the valve fails outright. Another ...

How to Adjust a Car Idle

How to Adjust a Car Idle As cars get older and accrue more mileage, the idle speed of an automobile may be higher or lower than it needs to be, either wasting precious fuel or causing the car to stall out. Adjusting your idle is relatively easy, with the same basic procedure for any car. However, be sure to check the specifications for your car before doing any of your own maintenance. Things You'll Need Screwdriver Instructions Start your car and allow it to cycle through at least one period of going through a higher RPM rate. This will ensure that the engine is completely warmed up and you will be able to adjust the idle properly. It is important to allow the engine to warm up because you will be driving your car mostly at that condition. While the engine is warming, you can pop the hood of your car and prop it open. Locate the throttle body. You can recognize it by tracing your air intake hose as it exits the air filter. The next part that the air hose...

High Idle Causes

High Idle Causes A high idle in your car can cause you to worry. When the engine seems to rev up on its own while you are at a standstill, you may wonder if it's a sign of trouble that needs the attention of a mechanic. The answer to that question depends on the cause of the high idle. Some causes are harmless, while others can indicate the need for a repair. Faulty Fuses Most modern car engines control the engine idle speed through a motor called an IAC (idle air control) motor. One of the leading causes of IAC motor malfunction is a blown or faulty fuse. A malfunctioning fuse in any of the electronically controlled components including the air bag system can disrupt the function of the IAC motor and lead to a higher idle speed than usual. Computer Malfunctions Computers control a modern car's engine and transmission, its brake system and its airbag system. If the fuses are fine, the computer system itself in one of these components might be malfunctioning....

The Causes of an Idle Surge

The Causes of an Idle Surge Fluctuations in engine idle speed can be annoying and may even cause stalling at idle. Engine stalling can be dangerous, because power assistance is lost to the steering and brakes. Idle speeds below those specified by the manufacturer will affect the performance of the power steering pump, alternator and AC compressor. Emission control devices also require a minimum engine speed for effective operation. Surges that accelerate engine speed could cause unexpected vehicle movement. Air Supply A clogged or obstructed air filter can cause surging at idle, and foreign objects can enter the filter housing at any time. Any debris in the filter or housing might restrict air flow to the engine enough to affect idle speeds. Clean the throttle body or carburetor venturi(s) after replacing a severely dirty air filter. Aerosol products designed for this purpose are available at any auto parts store. Instructions for use are on printed on the can. Fuel Sup...