2016 Mercedes-Benz C300 Purge Valve Replacement Cost

The purge valve is located in the vacuum line between the fuel vapor containment canister and the intake manifold. It opens at specific times to let fuel vapors stored in the canister be drawn into the intake manifold and burned as part of the combustion process. On most vehicles, the canister purge valve is computer-controlled.

The most common symptom of a defective purge valve is an illuminated check engine light. Usually, there are no noticeable engine performance symptoms associated with a defective canister purge valve. However, in some cases, black smoke may be seen coming from the exhaust.

You should be able to drive a vehicle with a faulty canister purge valve. But a faulty valve can allow raw fuel to enter the intake system cause the engine to run “rich” — this will result in black smoke coming from the exhaust. If you see this, the vehicle should not be driven because the catalytic convertor could get damaged.

There's no set replacement schedule for the purge valve, and it's not a part that fails commonly.

A faulty canister purge valve is usually diagnosed from a fault code stored when the check engine light turns on. The valve will be checked to make sure it's able to open and close correctly. If it's working, the part that controls the valve will also be checked.

The valve's location depends on the make and model of the car. Any items blocking access to it will need to be removed. The valve is then disconnected from its mount, hoses disconnected, and the new valve is installed. Any hoses or other related parts should be inspected and replaced or repaired as necessary.

It largely depends on where the valve is located in your car. If it's easy to access, and you have the tools and knowledge to do the job, it's a fairly straightforward job. Otherwise, let a certified mechanic handle this repair.