A&Q about 350Z
Q:
I have lowered my car by 40mm and it has begun to make funny noises. My car is a mk3 2.0 gti 16v. It sounds as if it is the exhaust rubbing on something. It only makes the noise when either the car is accelerating and is made worse by having a heavily laden car. A mechanic friend thought it was the exhaust rubbing on something that was too close. Standard exhaust. Any help would be really appreciated!!
A:
have you checked your exhaust heat sheilds haven't broken and are vibrating on the exhaust?
A:
I had a look under car and couldn't see anything obviously wrong. Also when I wobble the exhaust it doesn't make any noise
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take it you've checked all the exhaust rubbers aren't broken or stretched does the exhaust go over the back axle like mk2's i can't remember?
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Yeah. All mountings are fine. It does go over the axle and I think that this is where it is making the noise, don't really know what I can do about it though Thanks for replying.
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i can't see how lowering it would make the exhaust noisey have you checked your engine mounts
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The noise is definatly coming from the rear though. It increases with more weight in the car.
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When you lower the rear suspension, the beam moves upwards towards the underside of the car, and the exhaust. You'll need to adjust the position of the exhaust slightly to give some more clearance.
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also whren the engine tilts back under load, it shoves the exhaust back a little. Plus when the zaust heats up it gets longer!
Try putting jubilee clips round your old rubbers to tighten them up a little
A:
when i had my mk3 lowered 40mm there was a noise too... kinda vibrating creaky noise... not sure if this is the 1 your refering to... however it will go after bout 2 or 300 miles when the suspension is worn in a bit!
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Is the back box contacting the ground, when you're driving?
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A worn engine mount on my old mkII used to cause trouble with my exhaust until it was fixed, might be worth a checking as this is worse the harder you accelerate.
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i have the same on my mk3 16v thats been lowered 35mm.
under hard acceleration (and this thing accelerates like its been hit by a meteor) on bumpy roads, im sure the rear beam is hitting the exhaust.
i need new engine mounts, unfortunately that will be a massive job :(
A:
Is their anything else that would suggest engine mounts. At idle the golf does rock from side to side slightly. Does this indicate mounts?
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might as well replace the front mount, they arn't expensive and easy to change. Its also the most likly to be casuing the problem
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i heard that the mounts were a double hard job to do... space looks limited too
who else has done it ?
A:
I had the same problem (although it was before lowering) and it was due to an incorrectly hung backbox AND loose heatshield.
Have you tried actually shaking the heatshields? They are a common cause of such noise.
As a side line - Matt, is your 16v standard performance wise? I'd hardly say mine went like it's been hit by a meteor!!
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The front mount is easy to replace, you undo the fixings, jack the engine up until you can get the old one out, then drop the new one in
1 tip, don't lower the engine completly till you get all the bolts threaded a little
A:
I had the same problem (although it was before lowering) and it was due to an incorrectly hung backbox AND loose heatshield.
Have you tried actually shaking the heatshields? They are a common cause of such noise.
As a side line - Matt, is your 16v standard performance wise? I'd hardly say mine went like it's been hit by a meteor!!
haha... i was being a noob
A:
sounds ike the back box pipe is vibrating on the swing arm, my mate 172 did this, same kinda sound as if you put a spanner on the alternator fan?????
A:
Should be pretty obvous if its a heat shield or the actual exhaust. Heat shield will be a low level rattle (tizz) type noise. Most likely to be the one over the top of the back box as the push toothed clips rust then drop off so get under the back of the car and see if its loose. Other is the tunnel liner which means jacking the car up and crawling under have seen these hang low too. One other to check (if its not already fallen off) is the sh/t gard underneath the catalytic converter as these are prone to go. You can either try to wire it back up or just pull it off as I did.
Wouldn't have thought you need to replace any mounts. If it is the exhaust thats knocking on the rear beam (and this will be much louder and annoying under full load) then there should be enough adjustment in hte link pipe that conects the back of the Catalytic converter to the rest of the system that you can slacken the two sleave bolts (17mm if I remember) push the rest of the system further in (or out) so that the over axel piece sits where it should relative to the beam. My money is on rear portion of the system needing to come forward about 1/2 an inch.
My car is lowered about 100mm with an aftermarket exhaust of larger bore than standard all the way through and with fettling of the exhaust position my doesn't knock anywhere (although it has in the past on several occassions after I've had the exhaust on and off)
Good luck...I hate knocks and rattles! Drive you mad!
A:
Thanks very much for all the help guys. I will try and fiddle with the exhaust. It sounds as if it definitely is the exhaust rubbing on the axle so I will try and manoeuvre the exhaust around. This forum is wiked, the amount of help you get is amazing. Thanks again everyone