Mr Chef

Here's my older topic but I wanted to list both a better key word title for searching and provide an update to as to what I've found or not till this issue is solved.

Old post: https://www.evolutionm.net/forums/sh...d.php?t=322763

2006 MR, 25,000 miles completely stock. This annoying buzz/rattle started just 2 weeks ago and annoys the **** outa me. On the highway in 5th gear at 75 or so MPH it's so loud with the windows up that it's hard to hear the radio at times.

I took the car to a good friends house to jack it up, look and listen and go over everything we could to try and find the culprit. We tapped and isolated everything from the DP to the tailpipe and didn't find anything that really stood out. We tapped and isolated the heatshields and again didn't hear anything crazy or notice anything rubbing. We checked all bolts related the the exhaust. We looked to see if any cross braces were rubbing. We even stuffed the tailpipe and revved it to check for any exhaust leak but Nothing. We did find pebbles lodged above the pipes in various places but that is normal for the most part and after they fell the buzzing was still clearly evident.

What my buddy did notice was obviously an issue: The return line from the oil cooler is leaking at the crimping and kinda hidden by the protective sheath. ALL OF YOU GUYS SHOULD GO AND CHECK THIS WHEN YOU GET A CHANCE!

After careful evalution and several test drives and stationary runnings and listening:

1) The sound is a loud Buzzing-Rattle from under the car when the throttle is applied stationary out of gear between 4,000 and about 5,000 RPM.

So we feel it's not anything like tranny or clutch. The engine itself is solid, theres nothing loose or floating around the engine bay and the clutch feels fine. It's not the clutch rattle, I know what that sounds like and that is subtle compared to this NEW LOUD annoying Buzzing Rattle.

The noise is clearly defined above and is louder as the car has warmed up which reminds me of another similar noise I had on a previous Acura, It was the Catalytic Convertor Heatshield. But then it was a known issue and completely solved under it's warranty and listed in Acura's TSB.

Well when we revved and listened my MR's noise Did in fact sound near the midsection of the exhaust and if we guessed it could be the Catalytic converter itself. I also thought I had felt a decrease in power at least a stifling near redline. So we put 2+2 together and thought it's the Cat itself. Maybe the honeycomb is coming apart and clogging up the works and making the sound as well as a slight loss in power.

OK, fast forward to last Friday. I call and drop it off at the dealer. I absolutely HATE to do this. I don't trust any dealership service department at ALL. This same service department failed after trying to help me with my "Leak" when I first got the car, which is documented somewhere here on EVOM. Suffice to say When I had the leak they kept the car for a 4 day weekend and still couldn't solve that issue. Only me poking around here on EVOM and then actually wrenching around my car myself with a buddy and a garden hose did I completely solve that issue Myself. In short Dealers Suck.

So I drop the car off, I remark about the oil leak, then tell them about the exhaust sound and have the Service manager take a listen to the buzzing. He sort of acknowledges the issue and goes back inside and writes more up for the techs to read. He didn't want to come outside from his cozy office, it was about 30 degrees at 8 AM that morning, only after telling him that I demanded him come outside did he actually do it.

5 hours later I call to see the progress: Well they agree that the oil line is leaking and order a new line but will need me to return the next week for repair, and he tells me that they COULDN'T FIND ANYTHING WRONG OR ABNORMAL WITH MY CARS EXHAUST! Ok...

When I arrive to pick up the car I tell them that there is definitely a problem. But the SA say's that they have a few other EVO's there that they also revved and heard the same sounds from and say that there is no issue with mine and that it is operating normally and that after removing the exhaust and examining the Cat everything is fine with No Issues.

He goes on to say that my plugs are fouled and that with higher idling in the winter cold that this is the likely culprit for loss in power. H'mmm, could be but I'm not totally sold and definitely won't have them charge me $25. per spark plug plus labor to "see" if that is the answer.

So at this point the oil line part is on order. I'll use them to fix that. I finally found OEM plugs from SPARKPLUGS.COM for $11.71 a piece, will install myself. And when I have another chance this week I'll bring the car over to another friends shop and put it on a lift and start more problem solving in a more serious environment.

Any helpful input is always appreciated.

And guys please go check your oil cooler lines for leaks. Looks like I found my issue early and totally by mistake.

Thanks for any help in advance,

Chef

Mr Chef

Short end to the story.

Yonkers Mitsubishi said that they removed the cat and shined a light through it and saw no issues.

B.S. I looked at the bolts after their claim and saw the bolts still rusted on. Never removed. So they lied to me. Ok its a dealer I'm pretty used to that. Here's more information as it went down:

Originally Posted by 286bhp
Did you ever figure out how to fix the buzz/rattle from you stock exhaust?

https://www.evolutionm.net/forums/ev...ution-yet.html

I have the same loud saw-like buzz from my stock exhaust at 4500rpm. The dealer thinks it is related to the heat shields on the underside of the exhaust, but I am not convinced. Plus, the buzz only started after they did replaced my water-pump and accessory belt two months ago. I cannot see why the exhaust heat shields would start rattling after that service.

Thanks!


We could never nail it down exactly. We isolated all heat shields but that didnt do anything. When I removed and replaced my stock TBE with the Works TBE & RTP and that buzz went away completely. I have a different lighter humming buzz at much higher RPM now more likely related to the transmission but not the same sound nor an issue just a different sound that is not nearly as annoying as the original one I described.

Sorry I couldnt help more. In short it's related to the stock TBE somewhere. I had thought it was the cat but there wasnt anything wrong with it when we removed and looked at it.

compscibOi

iTrader: (19)

Downpipe is touching something? Mine was doing that, then we adjusted it away from other items and no more tiny rattle...

boostless

iTrader: (21)

don't our exhausts have a resonator? That sounds like the culprit which might suck because theyre welded in. Good Luck

skags

did you fix this as i also have a rattle buzzing noise , but only when the car is hot and seems to be when slowing down or stationary . it also comes and goes as it pleases ,.. but only does it when the car has been running for a while