Rattles after installing HFC's

mikey1600

Hey guys,

finally installed my HFC's over the weekend since I had a couple extra days off for Easter, ran into a slight problem and seeing if anyone else had similar issues so I can possibly work out where some rattles are coming from.

so just above idle it rattles every so slightly, then just under 2k RPM it's a lot louder and can definitely hear it easily like a vibration rattle noise, sounds like a flimsy piece of maybe heat shield or something is rattling.

so far I've had a cat back exhaust system on the car for about 2-3 months now and have never noticed any rattle at all, yet when I looked under the back of the car just above where the exhaust mufflers sit, there is a big heat shield looking thing with a piece that drops down, this was actually touching ever so slightly on the exhaust, but looks like its been like that for quite some time, as you can see slight rub marks on the exhaust system... so didn't think it was this, but I've bent this over on itself as it felt quite flimsy but hasn't changed at all.

I've got to get the car jacked up again and check everything over again I guess, just moreso voicing to get some ideas of what to check, maybe I can add some extra washers/rubber stops somewhere to save this is someone else has had similar issues...

for reference, running BERK HFC's and Invidia CBE system.

So far no CEL or anything, and the HFC's actually add quite a bit of performance, it definitely makes the exhaust much louder, can definitely feel gains up in the high end 6k+ rpm, where it kind of used to taper off a bit, feels like it pulls a lot more through this range to redline, screams! haha.

There is a big heat shield which looks to be held on by 4 bolts underneath the rear trunk of the car, has anyone taken this off without issue? always hesitant to remove heatshields...

nabenson

If you can get under the car (with it on stands or a lift), and with a cold exhaust you can follow the entire exhaust from the engine back. You should be able to see where it might be making contact with something, or if a shield or hanger is loose.

mikey1600

yeah will jack it up again on the weekend and put it back on the stands, installed it this way haha, couple things I'm thinking are either the heat shield at the back is now rattling because of the extra exhaust noise, I've got to re-check the bracket which goes across the underneath of car from CAT to CAT, on the standard cats they have a square piece of metal around the bolt which may act as an extra washer on the bracket I'm talking about.

was looking more so from people who have had rattles after install also to get a better idea of fixes people have done if they have had to replace/add anything in to stop rattles, I know I have to check all the bolts/make sure nothing is touching

Ridgerunner

My guess is you are touching the heat shield, You could drop your CBE down slightly by putting a washer or two under the mounting bolt holding the rubber doughnut exhaust hanger.

SS_Firehawk

If the rattle is coming from the driver side foot well near the pedals or tranny tunnel, it's the heatshield that was near the cats. Mine rattles when I'm accelerating out from a lower rpm; More so when it's hot or the car is warm.When I get it on jacks or lifts again, I'm going to try and bend it away some or attempt to get it removed if possible.

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