Should you Service or Replace Your Megane's Throttle Body?

For your Renault Megane to operate smoothly, it has to have the right mixture of fuel and air. The car's air intake system controls the amount of air allowed into the engine. While this system is made up of several parts, the throttle body is one of the car parts responsible for helping make sure that the right amount of air enters the engine. If this part fails, the result is that the engine can't get the proper mixture of fuel and air. Because of this, the engine will likely lose power.

Throttle Body Service

When your Megane starts acting up and losing power, this doesn't necessarily mean you have to replace the throttle body. It could simply mean that the throttle body needs to be cleaned.

During normal operation, sludge and carbon can be deposited into the throttle body by the PVC system, which can limit the part's ability to let enough air into the engine. Your mechanic can clean these deposits out easily to ensure the car is able to operate as it should. However, during the process of cleaning the throttle blade and bore, your mechanic will also check and adjust the air rate and use a computer-controlled idle with a sensor to test the car's performance. When properly cleaned, the throttle body should allow your Renault to idle like it did when it was brand new.

While having the throttle body in good working order can help keep your engine power up, regular service to the throttle body also helps to lower the amount of emissions the exhaust system produces. This cleaning should be performed at 15,000 miles, 40,000 miles, and 75,000 to keep the throttle body, as well as other Renault parts, in good working order.

Cleaning the Throttle Body

If you aren't mechanically inclined, taking your Megane to a mechanic to have the throttle body cleaned is advised. However, if you want to tackle this job yourself, you can with these tips.

First, you'll need to check and make sure the problem is actually the throttle body. Disconnected and damaged vacuum hoses can cause some of the same symptoms caused by a clogged throttle body. Check them all. This will take some time, but make sure each of the hoses are not only connected tightly, but also be sure they aren't cracked. Check for burns as well; these hoses can become burned if they come into contact with the exhaust recirculation tube or exhaust pipe.

If all of the hoses are tight and look like they are intact, the problem lies with the throttle body. The next step is to remove any wires on the air duct that connects the air cleaner housing to the throttle body. Make sure to mark where each hose and wire goes so putting things back together doesn't become confusing later on.

After that, loosen the clamps on the duct and remove it from the throttle body. Use a torch and look inside the throttle body. Open up the throttle plate using the throttle linkage so you can see more than just the outside surface. If the interior of the throttle body has an oily film or a dirt coating, make sure to check your air filter and the air duct. Both could be cracked or faulty, allowing dirt and debris to enter the throttle body. These car parts may need to be replaced before you can get back on the road.

While the simplest way to clean out the throttle body is to use a clean toothbrush with soft bristles and a mild solvent, it isn't the best way. There are three reasons for this. The first is the possibility that the build-up is so tough that you might not remove all of it with a toothbrush and may end up having the same problem with the throttle body a few months from now. The second reason is that some manufacturers use a protective coating inside the throttle body to reduce the amount of build-up in the part. If you scrub too hard or use the wrong solvent, you may remove this protective coating. The third reasons is that a sensor tip may be projecting into a little opening around the throttle plate. The wrong solvent or hard brushing could damage this sensor.

Instead, invest in a professional tool, often known as an intake snake, to clean out the throttle body. Once you have the right tool, you can begin cleaning the outside of the throttle plate, then open it and clean the inside. Keep in mind that the tool just allows you to scrub the deposits loose. After you're finished, you'll need to use a mild solvent and a clean rag to remove the loose gunk.

Keep in mind that cleaning the throttle body incorrectly can result in failure and the need for a replacement part. If you aren't sure you can take on this DIY task, get help from a professional.

Throttle Body Failure

While cleaning the throttle body can allow it to operate for quite a long time, these Renault parts can fail if not taken care of properly. Most often, failure is caused by the part becoming clogged with deposits of carbon and sludge. In some cases, the throttle bodies can break, however, and lose their ability to open or close and won't be able to let air reach the engine.

When this happens, you will often notice several symptoms, including:

• Poor performance

• Lack of power

• A 'reduced power' warning message on your dashboard

• The check engine light may come on if you continue to operate the car when the throttle body is clogged, as trouble codes will continually be logged by the engine

• The transmission shifts poorly

• The engine cannot run smoothly or idle correctly

Because problems with the throttle body can be noticed almost as soon as you start the car, you may notice these issues before you ever get out on the motorway. However, the problems can appear whenever you are driving. As soon as you notice them, you should visit your mechanic.

Sometimes a good cleaning is all your Renault will need. However, if the deposits have clogged the part too much or it is longer able to open and close on its own, a replacement will be needed. The cost for this replacement car part for a 2003 Renault Megane Saloon from GSF Car Parts is £138.60, plus the cost of labour.