Is this idle noise normal?

[Jayde]

It's only happened twice since I've gotten the car. Wouldn't a bad bearing be consistent though?

[Jason@Nameless]

Originally Posted by Jayde

It's only happened twice since I've gotten the car. Wouldn't a bad bearing be consistent though?

Well, hard to tell, so I'm not an SAE mechanic nor do I diagnose issues like this on a daily basis, so a Subaru Tech could probably speak a lot further on this than I can. Intuitively speaking, I'd suspect either the tensioner making the noise or the loose tensioner making something else like the free spinning a/c compressor clutch make noise.

I find it VERY hard to believe that multiples of these cars have bad tensioner/ac bearings from the factory. Bearings are one of those items that are pretty much great right out of the box always. Because they're built in such high quantities and because they are a precision item, they are usually quality assurance tested more than say, an object like a bushing or an exhaust.

And also, from my experience, little noisemakers like this are often reacted to by the dealership with 'nope, that's normal.' Case in point is the horrendous wastegate rattle on the Hyundai Sonata Turbo/Kia Optima Turbo. I know exactly where the tolerance slop and design is causing the noise (which translates to a high frequency exhaust buzz when you go full turbo-back on those), but the factory simply declines to address it. There's a good chance this is a similar (annoying but absolutely not a reason for long term concern) issue. If one of you experiences this, turn the a/c on and see if that isolates the issue to the a/c clutch bearing. We could also look at the BRZ here to see how much movement there is at the tensioner at idle and compare. That may be perfectly normal, just not something I've ever stared at before. Plus, at idle the potential for it to oscillate/move as rpm shifts slightly is probably far higher than if you were to mash on the gas and bring it up to a constant rpm. I'll see what ours does when we get the header finished.

Jason Griffith
Engineering Director
Nameless Performance, Inc.

[fenton]

Switching AC on doesnt affect the sound. Reving the engine up even 200 rpm makes it go away but once to a nice low idle you can hear it again.

Doesn't happen all the time, usually when driven for a while and warm. It is exactly how the videos depict, high pitched squeaking whining noise.

[NYC BRZ]

I have to look when I leave work but my old G8 used to have a crank pulley that wobbled like crazy. It would cause the belt to squeal. The dealership tried belt dressing, then just tightened the crank pulley once and then just replaced under warranty. Get it checked out. Its warranty so it doesn't cost you anything but a little time.

[robo_robb]

Originally Posted by fenton

Switching AC on doesnt affect the sound. Reving the engine up even 200 rpm makes it go away but once to a nice low idle you can hear it again.

Doesn't happen all the time, usually when driven for a while and warm. It is exactly how the videos depict, high pitched squeaking whining noise.

I'm with Fenton here. Mine behaves the exact same way in the same circumstances.

Here's an update from the dealer:
I took the car in today (6/15), I asked for a mechanic to come and listen. About 7 people show up, about 3 or 4 of which are mechanics. Even the Foreman was there. One of them has a WRX so he was familiar with how noisy boxers can be. He was positive the cricket noise was coming from the Direct Injection system (primarily from the drivers side). He said the tension pulley was behaving normally; the shaking was normal.

Both he and the Foreman suggested I hold off on leaving it at the shop until they do some research with their corporate contact, primarily because they have no other FR-S or BRZ to compare it to. They said they would contact me next week.

[Jayde]

Originally Posted by robo_robb

I'm with Fenton here. Mine behaves the exact same way in the same circumstances.

Here's an update from the dealer:
I took the car in today (6/15), I asked for a mechanic to come and listen. About 7 people show up, about 3 or 4 of which are mechanics. Even the Foreman was there. One of them has a WRX so he was familiar with how noisy boxers can be. He was positive the cricket noise was coming from the Direct Injection system (primarily from the drivers side). He said the tension pulley was behaving normally; the shaking was normal.

Both he and the Foreman suggested I hold off on leaving it at the shop until they do some research with their corporate contact, primarily because they have no other FR-S or BRZ to compare it to. They said they would contact me next week.

That's good news! Did he say if the cricket noise was normal too?

I know there are some issues with idle, and that a camshaft might be at fault.

[robo_robb]

Originally Posted by Jayde

That's good news! Did he say if the cricket noise was normal too?

I know there are some issues with idle, and that a camshaft might be at fault.

Thing is, they were on the fence about if the cricket noise was normal or not. They were leaning towards "normal," but just to be safe, they are going to contact Toyota to make sure. DI + Boxer = a plethora of strange sounds it seems.

[Jayde]

Originally Posted by robo_robb

Thing is, they were on the fence about if the cricket noise was normal or not. They were leaning towards "normal," but just to be safe, they are going to contact Toyota to make sure. DI + Boxer = a plethora of strange sounds it seems.

Thanks for the info! Keep us posted on what they say!

[yamaha16bw]

Mine does the same thing. I was wondering about it also and the only thing i could come up with myself is the DI system.

[Jayde]

After driving roughly 30 miles one way twice today, both times when it was at less then ~1000 rpms the chirping would start. It's really quite annoying.

[Razz]

I bet it is the belt tensioner, bad design or defective spring or supplier of spring cheated the manufacturer and used the wrong metals.

Damn thing sounds like a diesel truck from the old days. An exhaust will cover up a little but an louder intake will help allot.

[blu_]

This car will switch between port and direct injection at idle and there is a high pressure fuel pump sitting in the engine bay that could very well make that kind of noise.

You may notice, or customers may question, various sounds that change in volume and character from the engine and direct injection fuel pump at idle. These may be described as "clicking" or "clacking" sounds or a similar description. The sounds described are most commonly noticed at idle during initial engine warm up.

Be aware that BRZ utilizes both port and direct fuel injection systems. These systems are operated in one of three modes: Port Injection Only, Direct Injection Only, and a combination of both together. The transition between these modes of operation will occur automatically based upon inputs to the ECM. As the injection mode changes, there will be associated changes in the volume and character of the sounds coming from the injection system. Upon initial cold start, both direct and port injection systems are functioning. Within a short time (roughly 60 seconds, dependent on many factors), the port injection turns off and only direct injection is active. As a result, there will be a normal increase in injector sound volume. Shortly after that, injection will change from direct only to port only. After additional time, the mode will change back to a combination of both direct and port injection. These mode changes will continue to occur as decided by the various ECM inputs and will vary under changing conditions. Similar actions will also occur during hot start depending upon catalyst temperatures and other factors. These sounds are most likely quite different from what you may have experienced with prior Subaru models and are not a source for concern.

[NRGBalanced]

I've also noticed the chirping on my BRZ once, but it was so quiet with the hood closed that I had to sit in a quiet neighborhood, with the windows down, and the engine at idle to hear it. Roll up the windows, and all I hear coming through the firewall is the tic-tic-tic of injectors and valves.

[seannyice81]

Mine chirps as well. Will chirp when being revved a little too. Doesn't seem to do it under acceleration, in gear. It also doesn't do it first thing. It'll do it after driving for a little while.