New to this forum, but on my second WRX (first was an 02, current is a stock 06 with about 3K miles on it). Twice today it produced an extremely loud, concerning squealing/grinding sound. It sounds like metal on metal (not like a slipping belt) and it sounds like it's emanating either from the front axle/brake assemblies or the engine bay?

Both times it produced the sound, the engine was warm and the A/C was on, and both times I was decelerating in a straight line below 20 mph. The sound only lasted about 10 sec each time it occurred. The noise stopped each time I came to a complete stop, and I was unable to reproduce it when I tried. It also sounds as if it's tied to wheel rotation, as it slowed in frequency a little as I rolled to a stop.

Only guess I have is that maybe I overtorqued the lug nuts on a new set of wheels I threw on, and it's doing something bad to the hub or brake? I called Ira Subaru service for torque specs (they're not in the manual... go figure) and they told me use 100 lbs. But the consensus on this forum seems to be closer to 70 lbs, which has me concerned.

Anybody ever encountered anything like this? Thoughts?

take the aftermarket wheel off and inspect it for clearance issues...then put the stock ones back on and check for the problem again... if no problems with stock wheels, then you need to check if something is possibly rubbing or hitting your aftermarket wheels. the torque spec is about 70ft lbs., is the caliper hitting the wheel?

A couple of times this happened to me, the stick that holds the hood up on top of the radiator has come loose and starts rubbing against the accessory belts and makes a similar sound.

^^^ how does it come loose?

that happen to me also but it stoped doing it after i hit 100mph+
i know doesnt sound to logical and i wasnt trying to do it on purpose just stoped after that.

It sounds highly unlikely that your wheel lug torque is causing a problem. Unless you went too loose (which you'd know), there shouldn't be any problems if they are evenly torqued down, regardless of torque. If you go too tight, its possible to over-tension the stud and break it, but I wouldn't expect that to happen with 100 lb-ft.

As far as the sound is concerned, I've had a similar sound since I bought the car. It became more noticeable when I installed all the Kartboy/TiC bushings and especially so when I installed the group n tranny mount....so, I attributed this noise to driveline noise. It's not bad and if the radio is on or the windows are down, you can't even hear it.

Still though, its hard to diagnose noises over the internet, so don't take my word for it. If you feel its a safety concern, then no one here can help you...take the car to Subaru and use the warranty you are paying for!

Thanks everyone for your replies. Yeah, the next call I make is for a service appointment. The sound is closer to what you would hear on a train when it's rounding a tight bend and the wheels are screeching against the tracks (and it's similar in volume... it made pedestrians jump 30 yards away!)

I didn't think lug torque could produce that effect, and the torque was definitely evenly distributed, if a little high. Wheels are a Subaru-specific BBS fitment and there's no clearance issue with brakes, body, or suspension.

I've localized it to when I'm decelerating, no brakes, in second gear, mid to low RPMS, when the engine is under compression load. In trying to reproduce it, I also noticed a valve or exhaust noise during acceleration that seems abnormal, almost like a high-speed ticking that increases when the engine comes on boost, then disappears as RPMs level off. Thinking it may all be related (gulp!).

I will let y'all know the diagnosis in case you run across something similar. Cheers.

The sound is closer to what you would hear on a train when it's rounding a tight bend and the wheels are screeching against the tracks (and it's similar in volume... it made pedestrians jump 30 yards away!)

Wow, that is pretty loud. Definitely not the noise I was referring to. Sounds like its needs to be looked at though. Good luck.

really odd , i noticed the exact same problem undrer the same circumstances please let me know if you find it

I also noticed a valve or exhaust noise during acceleration that seems abnormal, almost like a high-speed ticking that increases when the engine comes on boost, then disappears as RPMs level off. Thinking it may all be related (gulp!).

I have the same noise on my 06. I was/am also a little worried about it, but I *think* it's normal.
I have never got the screeching sound like you are describing though.

Good luck!

Chad

So... it was just rocks jammed between both rear rotors and their backing plates. And it got louder as the temp rose b/c the rotor expanded enough to squeeze the rock and cause the squeal.

Makes me think the Goodyear Eagle F1 GS-D3 tread pattern is pretty flawed though. They throw pebbles constantly just driving down the street and always have rocks stuck in the center grooves. Which means the likelihood of rocks getting stuck back there again is pretty high. Not cool.

The ticking noise checked out as normal. No ECU codes or sensor trips. I guess maybe it's a sound that's just more pronounced in the 2.5L than the 2.0L (I had a 2002 before this). Since they both have this characteristic to a degree, it's probably that bigger, heavier valves make more noise on boost. But I ain't no mechanic.