Something rattling in the left front of the car.

Bmachine

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Ah... the famous "There is a noise in there somewhere, mister mechanic..."

I was wondering if anyone had run into something similar. I am getting a sound that is very similar to what you would get if you had a loose caliper on the left front wheel. Sensitive to any irregularity on the road so it feels like it is part of the unsprung weight. But the caliper is securely fastened, so are the wheel nuts, I don't feel any movement when I try to manually shake the wheel side to side or top to bottom and the wheel bearings are new. No noise on smooth surface so it's not a rolling noise. Strictly a "shaking" one.

It feels like something of weight, again maybe like the weight of a caliper. Not a loose relay or similar lighter item. Metal on metal although by the time it gets to my ears it is slightly muffled. Not sharp like if you would use a hammer on a piece of steel next to your ear. It feels like it is originating from the left front and then reverberating through the front of the body, so not something that would be attached to the motor and isolated through the rubber motor mounts for example.

I am hesitant to drive the car too far or too fast until I am sure it is not structural or affecting safety.

Any thoughts?

Thank you.
 

Bmachine

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Maybe the front strut top mount? Or possibly the shock if it's in really bad condition.
Top of strut would make sense. I will double check tomorrow. Especially since I have the CN camber plates which adds another possible culprit.

Struts are new Bilsteins, so unlikely unless something went wrong during their installation.
 

eriknetherlands

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Sway bar bushings can make 'crack' sounds when the bar rotates in it, coming from their stick-slip effect.
Funny enough, as rubber is involved you'd expect this to sound "dull" but it can be quite like a metal to metal "clang"

Two positive things about continuing to drive; you drive instead of pondering, and 2; when it breaks it is much easier to find...
 
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Bmachine

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Progress!

This morning my friend Gavin and I did some debugging. And we discovered that the noise is indeed coming from the top of the strut. But we can only reproduce it by lifting and dropping the left front of the car. There seems to be movement between the top of the shock and the rubber of the strut bushings.
This means either the nut at the top of the strut is not tight enough or there is something wrong with the front bushing.
First things first, I will tighten the nut as soon as I can find either an impact gun or the special socket that allows me to tighten it by hand while holding the Allen key.
 
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Bmachine

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Thanks very much for the offer, Steve. But I have a friend who is bringing a battery powered impact gun at Chris' Huntington Beach concours tomorrow. Hopefully we can fix the problem right there!

Bo
 

Bmachine

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Sure enough, that was the problem. The nut at the top of the strut was slightly loose. It's hard to believe how much noise (and uncomfortable noise at that) a seemingly tiny adjustment made.

Thanks all for the help.
 

Gary Knox

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Bo,

I had the same rattling noise at the right rear of my car when I bought it. PO said it was in the muffler system. I could not reproduce it via any method when the car was parked or on a lift. Turned out the nut on the top of the right rear shock absorber was loose. But tightening it very tight didn't completely eliminate the noise. I put in a new bushing when I replaced the Bilsteins with Konis. Tightened the top nuts on both sides firmly. NO noise now.

Glad you found it, and I too have found that impact wrenches are the best way to tighten those nuts on the front strut shocks.

Gary-
 
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