Ok... it's the usual questions... I guess I just want to know if it's normal or not. It definitely doesn't feel normal (and it wasn't there when I first got the car).

I'm a little bit of a newbie so be easy on me.

Ok, when I'm driving at highway speeds with my foot on the gas... everything is fine. As soon as I ease off the accelerator... I can hear this kind of grinding/rattling sound. This car has 1,500 miles on it and I have been treating it nicely. For the first 500 miles I didn't go over 4k RPMs and generally treated her like a lady. After about 800 miles I pushed it a bit more... but nothing that an EVO shouldn't be able to handle. (I have never launched this thing... if you were going to ask).

Besides this issue the car has been fine. It doesn't FEEL like anything in the drivetrain is loose... but it kinda sounds like it. I only hear the sound at higher speeds and only when I have my foot off the gas pedal... as soon as I hit the gas it's gone. I don't hear that 'knocking' sound that you might if there was a loose 'link' somewhere.

Any ideas for me?

 

Normal clutch break in is my guess. it is getting "seated". just a guess. I dont have an 05 though, so I cant be sure.my2c

 

dont worry is something of the antilag system only 2005 models have it thats if you hear it infront of the car in the engine bay its totally normal!!

 

Hum... anti lag, its a USDM model jrsimon27, we dont have anti-lag. As for the sound, does it resonate above a certain speed? If you decel, with your foot off the gas, does it make an obnoxious sound until a certain speed, and then just goes away? I am trying to get a feel fo what you are experiencing.

 

well i thought the late usdm 2005 had anti lag ive seen several people on this thread posting pics of it!

 

hum... Ill have to look around, Ill be damned if they do.

 

well i think is that some usdm owners have install this on there cars!

 

I have an 05 w/ 2700 miles. I'm not sure what that sound is, it's hard to explain in writing. But I have a similar sound. I hear a sound on my car at highway speeds when i let go of the gas pedal. I figure it has something to do w/ the turbo. Going from boosting and then not.

I would not worry about it.

 

It sounds to me like gear noise from torsional vibrations being transmitted from the engine. The springs in the clutch disc dampen these to some degree, but given the light flywheel on the EVO, and the clutch design, I would not be suprised if some vibrations get through. If it is from torsional vibrations, then there is no reason for concern. By increasing the weight of the flywheel or the dampening in the disc, these noises could be reduced, but this would also be anti-performance in nature.

 

ACTman could it be the throwout bearing. I was thinking transmission bearings, but it also sounds like a couple other people have the problem which would indicate a normal sound for the car.

 

why would the throwout bearing make noise on deceleration but not at cruise or acceleration? The throwout bearing is not load bearing unless you're trying to engage the clutch. I doubt it's the throwout bearing.

 

You took the words right out of my mouth (keyboard).

 

Well thanks for the comments. It comforts me to hear that other people are having the same sounds. I'll have to listen to it to tomorrow to get more details. From what I can remember it mostly happens at high speeds and eventually goes away when I get below a cetain speed. When I put my left foot on the foot rest thingy there.. I can feel a slight vibration. It really isn't too bad... it's the type of thing I can definitely live with if I know it's normal. I'm just worried that if something is wrong and I keep driving with it... I don't want to cause any damage.

 

If you modded the downpipe, then its that newer pipe hitting the front underbody braces. Buschur's downpipe was striking my braces, so I had them modified to accommodate the closeness of a Cusco H-bar. The engine is flexing under boost, as the aftermarket pipes usually do not have a flex-joint, so they hit the under braces and rattle. Tym Switzer showed me this common occurance, and he mostly stopped the annoying vibration from happening. When it rained is when I would really notice the rattle the most, but my stock car never had this problem. Hope this helps!