You start your car and a new sound greets you, a high pitched whine… Has someone installed a supercharger while you left your Subaru parked? Perhaps? Most likely they didn’t, but what would be that high pitched whine that increases with speed…?

There are many parts that come to mind but none that give off the sound quite like a Subaru idler pulley in it’s death throes. On the Sti it actually sounded like a supercharger whine, which was cool but when the idler gives up, so will your Air conditioner.

If you are hearing a loud whine when the vehicle is on we can take a long screwdriver or a stethoscope and place it right on the pulley nut. If you are hearing a much louder or similar sound, congrats you have found your problem. Now it is time to solve it. If you didn’t back to the drawing board and all the other front bearings that litter the front of the engine.

Time Frame

With the proper tools this can easily be completed within a half hour. If you have less than optimal tools it can take an hour plus. Small tiny arms and hands are also very helpful here.

Tools

For this job having a few long wrenches will really help speed up the process. I use my zero offset extra long wrenches to tackle this job. If you don’t have them you can still complete it, just with a few more scrapes and cuts along your knuckles.

My other favorite tools are my Milwaukee power tools. For this one the 3/8th electric ratchet will once again speed up the process.

Alongside my Milwaukee tools and ratchet will be my Grey Pneumatic sockets. I have been of fan of these for over the last 7 years and have yet to break one. They are strong and built to last.

Grey Pneumatic 3/8th socket set Gearwrench 3/8ths ratchet

Parts

You can go directly to Subaru for a new pulley. You can also head to your local parts store and find an aftermarket unit, either should get the job done.

Another frequent issue with these pulleys is the tensioner device will crack or break. If you are replacing a pulley it’s probably a good idea to just go ahead and replace both.

If you just want to buy both here they are! Link here pulley and adjuster set.

Installation

We will start our installation like many with a propped hood and locating our area of work. Up front and center will be all your accessories. From left to right, Power steering pump, alternator, and air conditioner compressor. If you have a belt cover now would be the time to remove it. These are generally held on by a couple 10 mm bolts and a nut near the Ac.

Start your way by removing these shields. Determined by your Subaru and model they may look a bit different.

With the cover removed you will now be able to see the belt and the routing. If you are going to change A/c belt and/or the power steering belt. You can head over to this link for a write up on power steering belt replacement.

If you intend to reuse the A/c belt you can start by breaking the nut loose that cinches the pulley to the bracket. With this loosened you can now release the tension off the belt by running the tensioner up. This is where the extra long wrench comes into play.

Loosening the lower nut on the bracket will allow the pulley to move up and down. With the tensioner bolt seen on the left side.

Tension removed from the belt. You are free to remove the entire bracket next.

Having completed those steps you can now move to the two upper bolts that hold the bracket to the engine. With those two bolts the bracket is now easily removed from the car.

The two bolts that hold the bracket assembly to the motor.

Next up you will fully remove the nut that holds the pulley to the bracket. You can now pop the studded pulley holder from the center of the pulley and transfer it to your new pulley.

With the pulley nut removed the parts can now be disassembled for replacement.

Take note how everything comes apart but it is quite easy to put together. it only really fits one way. Here the pulley, bracket, tensioner adjuster and pulley shaft are all separated.

If you are going to replace the plastic tensioner bracket that often fails this would be the time. Spin the tensioner bolt until it threads off and start the new one back on. The constant vibration, heat and stress can fatigue these, I had one break in the middle of the repair without a replacement on hand. Ever since then I replace both at the same time.

Now you can snug everything back together as it once was. and slide back into the car. Placing the belt back where it belongs you can now install the two upper bolts that hold everything together.

Once you have everything put back together it can go back in the car.

After those are fastened down, we can line the belt up on all pulleys and use the tensioner to get the belt ready to run again. You can use the tensioner bolt to eyeball where it once was, the threads will be clean. This is a good starting point, you can add or release tension as you see fit.

Line your belt up to the crank, adjuster pulley and A/c. Now you can start setting the belt tension. The belt should be able tight but be able to twist from side to side.

With tension set you can tighten the nut that holds the pulley in place. Now you can start the car and make sure the belt stays in place and isn’t squealing. A squealing belt is a sign of a loose belt. You can undo the pulley nut and add more tension till the squeal is eradicated. It is also a good time to run the A/c to make sure the engagement of the clutch doesn’t cause a squeal.

Putting your accessory covers back on and you should be done!

Having that part completed you may now reinstall your belt cover and take the car for a quick spin to make sure everything is working properly.

Congratulations! You have fixed your whiny Subaru! Now hopefully the rest of the bearings in your car will take not that whining will not be tolerated and they will be replaced if they start squawking.