The accessory belt on your Porsche 996's engine is responsible for driving the power steering pump, alternator, and A/C compressor. If the belt fails, you'll lose your power steering, water pump, and the battery won't be receiving a charge. Losing the water pump will quickly cause the engine to overheat and damage itself. Porsche recommends that the belt be changed every 60,000-miles, and the belt tensioner and idler pulley should get replaced along with it. If either of the bearing in the pulleys seizes, the belt can snap. A squealing during engine start or a turn is a tell-tale sign that something in the belt drive system needs replacing.
Replacing the belt on your Porsche 996 will be a fiddly job. Space is tight with the front of the engine against the chassis, so patience is needed here. Beyond that, though, this is a simple replacement DIY. A few tools are all you need to follow the steps below and ensure that you've replaced your accessory belt correctly.
Porsche models and years applicable:
How much will it cost to replace a Porsche 996 accessory belt?
Replacing parts on your Porsche can get pretty expensive, but replacing the accessory belt isn't. A new Continental accessory belt will cost you right around $20, and that's all you'll need for the job. You may want to replace the air filter while you have the airbox out of the car. It's another inexpensive job, and you can knock that out with just a few extra steps.
How long will it take to replace a Porsche 996 accessory belt?
Replacing the accessory belt on your Porsche 996 shouldn't take very long at all. Removing the intake system is straightforward and is all you need to remove to access the belt. Put aside around 20 minutes to complete the belt replacement.
Parts required to replace a Porsche 996 accessory belt:
Tools required to replace a Porsche 996 accessory belt:
Steps required to replace a Porsche 996 accessory belt:
Step 1: Remove the intake
Open the engine lid, and the airbox will be right upfront. First, remove the oil filler tube from the top of the airbox. Then, squeeze the two tabs on either side of the mass airflow sensor plug and pull it off the sensor.
Next, pull the oil filler neck off of the airbox cover and use an 8mm socket to loosen the intake hose clamp on the throttle body. To the left of the oil filler neck is the airbox snorkel for the engine lid. Pull that to the left to remove it from the airbox.
After that, use a 13mm socket to remove the single bolt mounting the airbox into the car. It is located just to the right of the engine lid latch. Then, pull the entire intake assembly up and partially out of the engine bay.
The wiring for the mass airflow sensor runs through a clip on the right rear corner of the airbox. Ensure that you remove the wiring from the clip before removing the intake entirely.
Step 2: Replace the belt
Take a 24mm socket or wrench and place it onto the accessory belt tensioner. Rotate the socket or wrench to the right, and the tensioner will slide the opposite way, removing tension from the belt.
Ensure you know the routing of the belt before removing it. Then, feed the new belt into the engine bay and wrap the belt around the water pump. Rout the belt around the remaining pulleys before using the 24mm socket or wrench to loosen the tensioner.
While holding the tensioner open, slip the belt under the remaining roller and into place. Then, release the tensioner and check the belt's alignment. Ensure the belt is sitting in all of the grooves on each of the pulleys. Failing to do so will cause the belt to fray and break or slip off completely.
Step 3: Refit the intake
Grab the intake and refit it into the engine bay. Use the two locating pins on the underside of the airbox to ensure the airbox is in the proper position. Then, run the mass airflow sensor wiring through the clip on the airbox's corner.
After that, slip the intake boot over the throttle body and thread in the airbox's mounting bolt. Use a 13mm socket to tighten the bolt. Then, pop the oil filler neck back into the airbox cover and use an 8mm socket or flathead screwdriver to tighten the intake hose clamp on the throttle body.
Finally, refit the airbox snorkel to the airbox and plug in the mass airflow sensor.
That's all there is to it. Replacing the accessory belt on your 996 911 is as easy as it gets and a great way to ensure it's performing at its best. If you're interested in more DIYs for your Porsche, you can visit porsche.fcpeuro.com and subscribe to our YouTube channel.
Owner of a flat-six swapped 1998 Impreza 2.5RS and a 1973 Porsche 914. Horizontally opposed views, only.