Valves and Parts for Audi A4

The Audi A4 and Audi A4 Quattro are compact executive cars made by Audi, a subsidiary of Volkswagen, and includes the sedan, station wagon, and convertible versions. The mechanical systems within your Audi depend on properly functioning valves. You can find replacement valves and other parts for your A4 or A4 Quattro as applicable for model version and year.

What kind of valves are there?

Valves and parts for Audi A4 primarily include valves for the car engine air intake and exhaust systems. These valves are called poppet valves and consist of a flat head with a long stem. Inside the engine of your A4, these valves open and close to admit air and exit exhaust gasses in the cylinders for combustion. Depending on the version of your A4, Audi A4 Quattro may have four or more cylinders, each with two valves. Your vehicle relies on these valves to support combustion.

Other parts also include other valves, such as the crankcase valve and valve accessories.

How do car engine valves work?

For each cylinder head on your Audi A4 or Audi A4 Quattro, there is a hole for air intake and another hole for exhaust. Both holes are covered by the head of a poppet valve. The head of each valve is inside the cylinder, but a spring pushes the valve head against the hole, making a seal. When the valve cam of your Audi A4 or Audi A4 Quattro turns, it pushes against the valve stem, which pushes the valve head away from the hole. The cams on your Audi A4 or Audi A4 Quattro are adjusted so that the valves open and close with the correct timing for the combustion phases.

What are signs of a bad valve on the Audi?

If an engine valve in your Audi A4 or Audi A4 Quattro has gone bad, it will affect the combustion cycle. This may cause your Audi to idle rough, backfire, misfire, or not deliver full power. You may also notice your vehicle has poor performance and excessive fuel consumption.

What are causes of valve failure?

The valves in your Audi A4 or Audi A4 Quattro may become bent or broken due to contact with the cylinder pistons. This can happen if the opening and the closing of the valve is not synchronized with the piston cycling in your Audi. The cams and the timing belt of your Audi A4 should prevent this parts collision. When a valve is damaged, it may indicate a different problem with these other parts that will require their replacement as well.

Another cause of valve failure in your Audi A4 or Audi A4 Quattro is that the valve does not seat properly, allowing hot combustion gasses to burn away the edge of the valve. A timing problem may not cause burnt valves. If your Audi has a burnt valve, the valve should be replaced as soon as possible to avoid damage to other parts.