Idler Pulley DIY Guide?
 

Hey Guys,

Was wondering if anyone could help me out with a guide to replace one of my idler pulleys? The idler pulley below my intake seems to making the noise. It's making a whining sound and sounds like I have a supercharger under the hood when I accelerate (I don't but wish I did lol).

Thanks guys!

Have you tried giving it a shot of oil ...... ??

(oh, maybe it's a sealed bearing ......:iono:)

Oh, :slap: humfrz ...... if you're not sure about what you're talking about, shut the hell up!

Hahaha! You know what, I should probably do that. Thank you sir :D

No no no, @humfrz. :slap:

OP, if you want to fix it yourself, order a #1 idler pulley sub-assembly.

Accessory belt removal

Some relevant diagrams & torque values

Well, OK, @shellslinger ...if you want to do it the hard way ...... just follow ol @Ultramaroon's instructions.

I'll just put my oil can away ..... :sigh:


humfrz

Thank you, we can always count on! @Ultramaroon and @humfrz :D

Be super careful cocking that tensioner. Do not use an open end wrench because it will slip. Use a box end or a socket. Note that the tensioner pulley bolt is left handed.

Good luck!

Yep, with @Ultramaroon ..... you get the first class approach; with humfrz, you get the "Bubba" approach ...... :)


humfrz

Key point, there.

Reminds me of a story about my neighbor, who was some sort of a physician, was working on his truck one day. After a lot of swearing he came over and said that he had seen me work on my vehicles and maybe I could give him some advice.

He was going to replace the serpentine belt but couldn't get the bolt on the idler pulley to loosen up. Yep, for sure, it was a left handed threaded bolt and he was mumbling "lefty is losey". I explained that generally that would be correct ...... except for left handed threaded bolts.

A few weeks later, I went under the knife for some operation, and after they gave me my "happy" shot, I was laying there on the operating table when Fred (my neighbor who was working on his truck) appeared and explained he was my anaesthesiologist.

I gasp my last conscious breath, as he was messen with the valves on the tanks ...... grinning at me, mumbling ........ lefty losie .....rightsy tightsy ....:eyebulge:


humfrz

No way! True story? Scout's honor?

@shellslinger, only the tensioner pulley is left-handed. The rest are normal.

Yep, that was a true story. Fred was quite a character. When I was a real estate broker, I sold that house to him and when he moved, I sold it for him.

He had this super sexy live in girl and she liked to do yard work, dressed in little of nothing...... and that's enough of that story .....:bonk:

He had two circles of friends, one group was his professional friends and the other group was a bunch of bikers (yep had 4 Harleys).

One Halloween he invited us over to a "party". The medical professionals were dressed up like bikers and the bikers were dressed up like medical professionals ....... we came to find out during the party.

Just goes to prove the old "book by the cover" saying.


humfrz

You know the rules: pics or it didn't happen.
It's certainly is not enough of that story.

Well, she looked sort of like this (not an actual picture of her).

It was a warm summer day, I was in my front yard, when I heard whooo-thuda-thuda. Whoo-thuda-thuda. She was trying to start her lawn mower. So, of course, being a decent shade tree mechanic and good neighbor, I ran to her assistance. Sure enough, the mower was out of gas, so, I went back to my garage and got some gas for her mower.

She brought out some iced tea and we sat on her front porch, sipping iced tea ...... when, I decided it was time to leave. Why?? Because, I would have been afraid that her husband might find out if things progressed and the next time I went under the knife and he was the anesthesiologist, I just might not ever come out from under ...... he might get his "lefty & righty" confused ..... :eyebulge:

humfrz

Man this thread went from asking to help to something awesome :D @humfrz and @Ultramaroon.

Yep, just a couple of good ol boys .....haven some fun ..... :D


humfrz

Always a fun and learning experience from both of you LOL

@humfrz' has lived a pretty awesome life. I'd love to hang out on his porch for an afternoon of lemonade and bullshit.

Here we are ...... Ultramaroon and humfrz ...... :lol:


humfrz

HAHAHA, perhaps this future Texan from California can join ya'll one day :D

Oh ya, we have room on the porch ....... but you have to bring your own rocking chair ..... :) ....... and girl ....... (these here two are spoke for....:D).


humfrz

Just wanted to update, I fixed the issue. Idler pulley was bad :(. But thanks @humfrz and @Ultramaroon for the help :D

Literally took 20 minutes to replace.

Thanks for the update ......glad you got er fixed..... :thumbsup:


humfrz

Sounds about right. Good on ya!

Mine was not left handed. It did, however, have some loctite. I'm guessing this is why the pulley part of the tensioner is not a separate part; you can only order the entire assembly (23769AA040). This assembly may have changed over the years. Mine is from a 2015 BRZ.

And to be clear, the bolt holding the tensioner to the alternator bracket is also not left-handed; that one requires a 8mm male hex bit socket.

Thanks! I saw that my links were dead so I fixed them. Even the 2017 manual still has the note. :iono:

Thanks for updating the links.

My car developed a faint whirring noise on Saturday morning before I left for a 5hr road trip for autocross. By the time I got home, it sounded like I have a super-charger. I think I found the culprit this morning, but to be safe I'm replacing all the idler pulleys, tensioner, and belt.

I ordered parts today. My local dealer said that the tensioner assembly (23769AA040) has been superseded by 23769AA111. The pictures in the online parts catalog (parts.subaru.com) show that as a zinc-coated steel part. The one on my engine is definitely aluminum (probably die-cast). I would be curious to see what a 2019 engine comes with from the factory. A friend that works at another Subaru dealer says he can order the original part (23769AA040). Not sure what's going on with these tensioners.

Edit: The link to the service manual shows the tensioner as part of the alternator bracket (they are an assembly, not individual parts). I wonder why there have been so many revisions/changes over the years? I am not aware of the accessory belt being a nuisance on these engines.

Update: 23769AA111 is not the correct tensioner. One of the ears/tabs on the base interferes with the alternator bracket, and it won't fit.

I ordered 23769AA111 for my 2013 brz.
https://www.subaruparts.com/oem-part...elt-23769aa111
I can't find any instructions on how to replace this part in the service manual.

Can't even find the torque spec on the 8mm hex bolt you mentioned.

Did you end up replacing your tensioner?

No, I didn't replace it. I re-used the old one, since the one I got at the dealer doesn't fit. I think I torqued it to 30 ft lbs. I also did not see the torque spec anywhere, so I had to guess.

Superseded part # is actually 23769AA110

The part number is discontinued. I ordered using this part number (23769AA040).