steveo55

So ive had the ARK system for a while with no problems. For the last month there is this horrible sound under car sounds like its right behind the front seats. Rattle thumping type sound. Its worse in morning when cold. I took it to shop first time they said theu couldnt hear it but put car in air and all looked fine. Second time i test drove with them to show noise and they heard it but said everything looked good and that it was because of aftermarket exhaust but couldnt do anything. That makes no sense. Its horribly loud in morninga sounds like its coming apart. Or could be hitting something. Anybody else going through this? Any ideas?

simon3huna

Hey, i had a similar problem right after they installed mine. All it is is the pipe hitting the casing under the car. Get the car on a lift up and see where it hits. might need to adjust it a little.

asiandavid

Im sorry for bringing the thread back but better than starting a new one im having these exact same issues 3 days after the install did you find out what the issue was?

iSuxeL

iTrader: (21)

Did you use the springs on the exhaust bolts? Assuming it has it like the 2IS

asiandavid

No the ark exhaust comes with its own nuts and bolts and gaskets only yhing that was reused was the nuts and screws from the cat and the gasket from the cat first two day it was fine no rattle or anything third day was when it happened

asiandavid

Just checked everything and everything tight no loose bolts and all hangers are in place and still has the thump sound

steveo55

Mine got fixed with some washers. The exhaust was hitting this bracket that was towards the middle rear. My buddy added some washers to give more clearence and presto noise gone

asiandavid

Are you talking about the middle brace that had to be removed on install? Thats the only thing i can think of that would come in to contact with the exhaust.

Swacer

Asiandavid

Like I posted in the other thread you posted in:


Does it sound like a metallic rattle/grind? If so, you don't have enough clearance between the exhaust and the frame/heat shields.

Keep in mind, several factors here:

1. The motor mounts allow the motor a LARGE range of motion (because Lexus owners don't like to feel the engine ). Have someone start your car with you looking under it and see how much it moves. Its quite impressive how much the entire setup moves. You have to accommodate for that.

2. The exhaust will grow and move as the car gets hotter, so clearances will change. If you are close to the frame when cold, you are probably hitting it when hot. Or you're now ringing off a heat shield.

3. As the car hits bumps, the motor mounts will absorb some of that motion, and it will be transferred to the exhaust, thus the exhaust is going to bounce around and hit the frame or shields.

I would recommend that you go back under the car (after it has run, wait for it to cool down a little unless you have high temp gloves - great investment if you don't), then start feeling the entire exhaust. If you can't fit your fingers into a gap (not your entire finger...but enough to feel space), loosen the exhaust and tweak it to make more clearance. If you're finding you have little clearance with a heat shield, don't be afraid to just bend the thing. I bent 2 on my wife's car.

If you've been rubbing the frame long enough, you should see black paint on the exhaust where its hitting as its melted the paint off the frame. Then you'll know exactly where.

This is normal occurrence for an aftermarket exhaust, it took me 2 additional adjustments to get my wife's IS right. Just make sure when you're adjusting the pipes that you have someone standing at the back of the car to make sure the tips are still pointing true.