I have a 2013 Evo gsr with about 2500 miles on it. Car is stock other than a cb exhaust put on last week. For the last 1000 miles or so, there's a weird metallic rattle/vibration that occurs in any gear upon deceleration from anything above 5k rpm. Once below that, it goes away. It's not coming from inside the car or the aftermarket in dash nav unit because when I drive with the windows down near a tunnel or walled median, I can hear the noise distinctly coming from the front of the car. Here are some vids. Any ideas???

 

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or there's a loose bolt on an exhaust heat shield from when the new exhaust was installed

 

The rattle has been around ~1000 miles before the exhaust was installed last week. On as side note, I took the car in yesterday to the Mitsu dealership to have it looked at. To sum up my experience, it was the worst I have EVER had at ANY dealership! After being told they can't replicate the sound (which I find hard to believe since it is extremely easy to do), I offered to drive with them and point it out. The service guy says it doesn't matter anyhow because my car is lowered (springs only), they can;t get it on the lift. I told him that three other shops managed to get it up on a lift so I can't believe they wouldn't be able to. Next he says, it still doesn't matter because by putting on the exhaust (cat-back only), I voided my entire warranty. This is where I got super pissed off and told him that he's basically an idiot. Anyone that knows anything about cars knows that a cat-back exhaust alone does NOT damage the engine or engine components. I also asked him how he can possibly make such a bold and stupid statement when he hasn't even heard the sound or diagnosed the problem?! I asked for my keys and left pretty upset. I made sure to post a terrible Google review and sent the GM a detailed email about my abysmal experience at the dealership. End rant/

 

dont worry, they have no better service over in the UK, I have had several emails with Lance Bradley about the level of customer service, its something they are working on

 

Unfortunately any mod will void the warrantee. It's in the fine print

 

Yeah it doesn't void your entire warranty, just a butthurt tech. My dealership is way cool and actually just takes the front off their allignment rack to fit mine on. For the lift, not sure what htey do, maybe drive it on 2x4's up. I dunno. But I do know-always tip your techs! Good, too, like $20. Makes problems disappear

 

Anything after the CAT is fair game and it is IMPOSSIBLE for them to void your warranty for such a modification; furthermore, for them to attempt to do so they have to prove that the aftermarket component had a direct and negative effect on a RELATED component. They have the ability to void your exhaust corrosion warranty but that's about it. If they give you **** have them read the Magnuson-Moss Warranty Act which states that any modification or alterations to factory components only voids the warranty for those components...for example: your lowering springs could cause an increased wear on struts/strut bearings/steering components/increased wear on cv axles etc...but they cant say that your motor blew up because of your springs...just like they cannot say your warranty is void because of a Catback, while you have increased the exhaust flow slightly, the retaining of the CAT does not alter boost characteristics or mess with fuel trims/electrical components and so on.

In my opinion that noise is probably the heat shield around the factory CAT, had the same noise after my exhaust install.

Next time a tech says your warranty is VOID, have him place that in writing with a brief explanation as to why and provide that to a lawyer. Dealerships hate warranty work because they lose money, the factory will only reimburse for X amount of labor and provides the parts where as a non warranty repair has only a RECOMMENDED labor guide and dealerships often overcharge or increase how much they charge an hour...I had a buddy of mine that worked as a service manager for Ford and showed me the Invoices of non-warranty repairs vs. Warranty repairs for similar if not exactly the same things.

If your disgruntled always pull the service manager aside and get them involved, if you make it apparent that your knowledgeable then they will not be able to bull**** you. They know they cant do it so stick to your guns and get it done.

Pisses me off when service pulls **** like his!!!!!!!

 

I would guess that it is the aftermarket nav system.

 

So I figured out what the problem was. It's the heat-shield covering the turbo just behind the engine. It's weird because I haven't messed with it at all (no downpipe, etc...) Car only has a few thousand miles on it. The shield itself was easily moving around and the bolts were tight and couldn't be tightened any more

I think that the OEM washers are too thin and don't put pressure on the shield when tightened so I removed them, added some metal washer substitutes (I didn't have any washers on hand...ghetto, i know). Re-tightened everything and now the heat-shield is rock solid. Noise is gone!!!

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