Hey everybody -

I guess you gotta break down and ask about mysterious noises at some point . I've got 2 - one that I'm closing in on, the other I have no idea.

'94 R2, ~68,000 miles on the chassis, ~1500 miles on the motor. Car has never been in any major accidents, and runs and drives awesome.

First sound is coming from the air relief system. The air pump pumps air into the air control valve, and it dictates where the air can go. One "air destination" is relief, which is excess air the ACV doesn't need. This vents into the stock airbox's silencer, then out the "extra tube" on the airbox.

Anyhow, whenever there is a relief air condition (cruising, part throttle/low RPM) I get a somewhat high-pitched whistling noise. Looked at it at lunch - it's definitely from the relief air, as unplugging the airpump made the sound go away, and you can only hear it when it's venting excess air. I'm guessing something's funky with the air control valve - maybe a bad gasket, not tightened fully, etc. The previous owner installed the motor and did a decent job, but there are a few "finesse" things that he missed that I'm finding, this being one of them .

Second sound is from the back. It literally sounds like an old stock airbox is in the hatch, and it bumps around when I go over a decent-sized bump. It's a hollow, plastic sound. I thought it might be the spare tire, as the holddown for the spare was missing - I removed the spare, no change.

Any ideas on either of these?

Thanks!
Dale

 

Do you have the Bose system in the trunk? And did you check in the two pockets on the side if somthing's in there that shouldn't be?

 

No Bose system, thank god . Thoroughly checked the two tool storage areas on either side, nothing there.

Almost wonder if it could be the exhaust whumping around. It's a OLD OLD school Greddy/Trust cat-back. It's well made and seems to fit OK, though.

Dale

 

Grab the tip of the exhaust and shake it up and down to see if it hits something.

 

Yeah, as I was writing the post it hit me that it could be the exhaust . I plan on doing that when I get home tonight and see what I get.

I'll keep everyone posted.

Any ideas on the whistling noise around the ACV?

Thanks,
Dale

 

Not sure but I have the exact same thing so I'd be interested to know what you do if you end up getting it fixed

 

Well, I messed with the rear clunk sound today at lunch and I think I found it. The exhaust piping is bumping the subframe of the car - it's pretty easy to get it to bump into the subframe. I'd be surprised if that wasn't it .

Solution to that will be new exhaust . The car has an OLD OLD OLD school Trust/Greddy cat-back. My guess is it was made shortly after the FD was released, and doesn't account for the extra bracing they added to the subframe in '94. I've been planning on going with an HKS Hiper anyhow, so no biggie there. I might try and rig something up to keep the noise down for the short term.

Next is the whistle from the front. Questions on that -

- Is the air control valve gasket metal or paper? I seem to recall seeing a paper one on someone's car I worked on a LOOONG time ago.
- Do the various actuators screw into the ACV? I know on the FC they did. I might be able to pull the relief actuator, clean it up/etc. and hopefully that could do the trick.

Any thoughts on the ACV sound?

Dale

 

OMG, thank god for this thread

i have a huge question mark in my head regarding my engine tone..

ok, all 11 months or so owning my fd has been great (knock on wood), the engine has been nothing but great news.. i would WOT in 3rd gear and the sound of the engine would be soo lovely, almost to a point where it sounds soooo smooth, it doesnt even sound like a normal engine, just awesome tone and i loved it..

HOWEVER!!!!

today i had my clutch changed, on the way home, i noticed how different the engine sounded, the first wot i did was in 3rd just cause i love the 3rd gear pull..anyway, as i was hitting boost, the engine tone was wayy different, nothing i ever heard of on this car since the first day i brought it home.. it sounded like how a honda would engage vtack (lol) but in a slightly lower growl.. i was like whoa whoa wait, this is not my car.. boost is fine, it revved fine, just a different engine tone..i just got home about an hour ago and this has been eating me so far..

only thing changed was the clutch, i dont think the clutch has anything to do with engine noise correct? cause if thats the case, i want my old clutch with problems back so i can have that beautiful engine note..

any thoughts or opinions would be great..

i mean its soo hard to explain, my previous engine tone was soo nice, didnt even really sounded like a rotary engine (from inside the cabin) but now it REALLY doesnt sound like a rotary engine.. idk..its weird and difficult to explain..