knocking sound after lowering my na8??

[erecsean]

hey guys, i just lowered the rear of my car a couple of hours ago, and now it keeps on making this knocking sound. at the start it sounded like it was coming from both sides, so i jacked the car up again and checked if all the bolts were tight enough and found that the tie rod end bolt was no tight enough. went for a quick test drive and now its only making the same noise but on the Right hand side. i checked all the bolts on both sides and they were tight. any suggestions on what it could be?

[Apu]

Pop the bonnet, bounce the car a bit and see if the shock tops are moving. I've had that situation before...missing a spacer.

Or it could be sway bars coming into contact with something.

When do you hear the noise? All the time? Turning only?

[Tezzax5]

Did you remember to reinstall the plastic gasket that fits between the top of the shock and the underside of the car where the shock pokes through the boot of the car?

[93_Clubman]

Worth checking the exhaust isn't knocking against something.

[erecsean]

Its coming from the back right of the car. Its not when i turn. It makes that noise even on slight bumps. Plastic gasket is still in there. Pretty sure its not the exhaust either but will check it out.

[Steampunk]

how is it lowered?

[erecsean]

i dont mean to sound rude, but i dont quite get your question on how was it lowered?

[Black_Penguin]

As in did you use lowering springs? Adjustable coilovers? Or (hopefully not) cut the springs?

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[erecsean]

Definately not cut springs. I used lowered springs. Apparently its the eccentric bolt?

[manga_blue]

A lot of these knocks come from the exhaust hitting something. Lowering the car can bring the control arms closer to it. It's not good enough just to look at it while it's standing still. The exhaust swings back and forth a fair bit with cornering and the engine rocks from side to side with acceleration and deceleration, moving the exhaust with it. You need to push the exhaust around a fair bit and also to look for any rub marks on the exhaust and on any parts it could hit.

[erecsean]

i know the knocking sound is definitely not coming from the front part of the car. its definitely coming from the rear end of the car. mpre towards the drivers side. but i will check out the exhaust tomorrow morning and see.

[Mr nanotech]

I had the same noise ages back. Turns out my rear shocks had blown. Fluid everywhere and any tiny bump would sound like a hammer

[erecsean]

i didn't replace the shock. used the same stock bilstein ones that came with the car. before it was lowered it didnt make that noise :/

[Mr nanotech]

Yep same with mine. But they may not be valved for the new spring rates.

[erecsean]

All fixed. Turns out it was the middle bolt for the strut. Lol.