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fenrisx
05-13-2013, 06:24 PM
Time for another round of the ever-so-popular "Guess That Noise!"

In this week's episode my 4Runner is making another weird noise. The noise is similar to that of an exhaust that's dragging the ground, mixed with a metal rattling noise... at least that's what it sounds like from inside the vehicle.

It typically doesn't do it when I start the 4Runner, but as soon as I put it into gear it makes the noise. Upon accelerating it will stop, but sometimes it will still do it depending on speed/rpm. It's not always an exact speed/gear/or RPM, but it does tend to be at spends under 30'ish MPH under light acceleration. Then again the sound of the Borla + wind noise could be drowning it out.

It seems to be coming from the front passenger side area of the 4Runner. My guess is maybe the front catalytic converter kicked the bucket (I've got the 2-cat'd Cali spec 4Runner)..and the innards are rattling around inside of it. I just YouTub'd "catalytic converter rattle" and found a video of a Honda that's making a very similar noise. (http://www.youtube.com/watch?v=_jk48X85LsM skip to the 1 minute mark). My only doubt with this being the cause is the fact it only does it once I've put it into gear.. you'd think it'd do it all the time at idle. Only a very few amount of times has it done it while in neutral.. which has made it difficult to diagnose. However, after watching that video I might try hitting it with my fist to see if I can hear anything inside bouncing around.

Anyone else want to back up my catalytic converter theory? I should try banging on it when I leave work..but I don't want to get my shirt dirty. :0

Seanz0rz
05-13-2013, 06:31 PM
I'd get under it and check for contact between stuff that shouldn't be touching.

Look at engine mounts and trans mounts, as well as the gas tank/dshaft touching. Kinda sounds like a bad trans mount that is allowing the engine to shift over while in gear and rattling.

fenrisx
05-13-2013, 06:35 PM
I shall put that on my list of to-do's this weekend, assuming I don't head north with my work amigos to ride RZR's. I just moved into a town house and now have a garage. :) Finally get to put it to use.

Thanks for the list of other possibilities. Although finding the catalytic converter would be much easier for my eyes to find... maybe if it's a mount it won't be as costly of a repair....?

Good Times
05-13-2013, 06:59 PM
did you check the underside to make sure everything is bolted up and nothing is getting loose? perhaps the exhaust manifold/header to the cat nuts/bolts or the cat to exhaust nuts/bolts/springs are worn and loose?

just throwing it out there :)

fenrisx
05-13-2013, 07:18 PM
Honestly I have checked anything at this point. Between the shitty weather, moving, and swamped at work.. I haven't had the time, energy, or cooperating weather. Now I have a garage so I can't use the weather excuse at least...

fenrisx
05-14-2013, 06:08 PM
Well that was easy enough. Beautiful day today... got home from work and crawled under the truck.. went to bang on the front catalytic converter and it rattled, and noticed the shroud around it was not bolted together on the back side. Went to bend/break it off when I decided I'd looked through the tool box for a nut & bolt first. Found two nuts & bolts in a baggie labeled "running boards".... which are on my truck..so not sure why I have two extra bolts.

Tried one out and it fit perfectly through the hole. Shroud secured, sound gone.
http://farm8.staticflickr.com/7292/8739106215_b14ec3db35_z.jpg

Seanz0rz
05-14-2013, 06:23 PM
Yay! Glad you fixed it!

Good Times
05-14-2013, 07:35 PM
awesome!