Loud 'thunk' when driving over a small elevation in road

Color · Post by **Color** » Tue Jun 19, 2007 1:44 pm

The other day I was out driving and at an intersection sped up to cross before the light changed to red. What I did not see due to the markings in the road was a small acute elevated ridge just at the entrance followed by a small depression which subsequentely lead to what appears, from the g-forces we felt, to have been a small jump and a hard landing. At what seems like the same time as the hard landing there was a loud thunk from the car.

It was rather loud and got us worried. After an inspection around & under the car as well as the suspension mounts I could not see any visible damage anywhere. My guess is the springs was contrated fast & to it's limit and the thunk was from the springs when they could not contract any more.

Our speed was not very fast, this was a 50 km sone and we were probably going at 10-15 over at the time (sped up to cross before it turned red, remember).

So I'm curious if anybody have had similar experiences, or any one which is more car-wise than me could give me any clues as to what the big metal thunk really was and if I should have the car revised in any way.

Thanks.

zee42 · Post by **zee42** » Tue Jun 19, 2007 8:07 pm

sounds to me like the struts compressed completely on landing and made the loud sound you heard.If your car is driving ok now i would not worry about it.should any issues arise in the future have them checked,you might have bent one of them,could also have been the car bottoming out,in any case if you damaged anything you would be able to tell by now.Quit trying to impress the chicks and drive like a normal person from now on

Color · Post by **Color** » Tue Jun 19, 2007 9:53 pm

You are asking ME, with that cat/shark avatar, to be . . . NORMAL ? ? ?

Thanks for posting your opinion on the sound, by the way!

It had us scared for some seconds until I checked the car and found nothing.

WLH · Post by **WLH** » Tue Jun 19, 2007 10:05 pm

I had the same thing happen to me. Miss judged a railroad grade and got air. Hard landing and an alarming loud thunk. That was about a year ago and no damage has surfaced...

zee42 · Post by **zee42** » Wed Jun 20, 2007 10:37 am

Color wrote:You are asking ME, with that cat/shark avatar, to be . . . NORMAL ? ? ?

Thanks for posting your opinion on the sound, by the way!
It had us scared for some seconds until I checked the car and found nothing.

I realize that asking you to be normal is quite a stretch...but I thought "what the hell...I'll give it a shot"

zee42 · Post by **zee42** » Wed Jun 20, 2007 10:40 am

WLH wrote:I had the same thing happen to me. Miss judged a railroad grade and got air. Hard landing and an alarming loud thunk. That was about a year ago and no damage has surfaced...

That's easy for someone who got kicked out of the state of Maryland to say !!!!!

WLH · Post by **WLH** » Wed Jun 20, 2007 11:51 am

zee42 wrote:
WLH wrote:I had the same thing happen to me. Miss judged a railroad grade and got air. Hard landing and an alarming loud thunk. That was about a year ago and no damage has surfaced...
That's easy for someone who got kicked out of the state of Maryland to say !!!!!

Hey...I been kicked out of bigger states than Maryland...

pvr · Post by **pvr** » Wed Jun 20, 2007 11:56 am

On topic again ...

Slightly surprused that a jump would do that though. On my other Z, I had a 4 wheel lift off (by accident) and landed without any noise what so ever (except for my "ohhh shhhhhhhhh*" )

ovrkll · Post by **ovrkll** » Sun Jun 24, 2007 6:24 pm

May have been the differential causing the "thunk'.

zee42 · Post by **zee42** » Tue Jul 03, 2007 10:09 pm

I think he pushed his wife out

Ski · Post by **Ski** » Tue Jul 03, 2007 10:44 pm

It was probably your ride bottoming out..

ay8306 · Post by **ay8306** » Tue Jul 03, 2007 11:18 pm

If you landed hard, you might want to think about an alignment check. Even if you did not do any permanent damage, you cold have buggered your alignment which could cause sevre tire wear.

dario · Post by **dario** » Mon Jul 16, 2007 9:44 pm

this has happened to me several times and it is generally how you described it. the THUNK is SOOOOO loud that you think the dash is about to detach itself.

IMHO it is the shocks being compressed too fast by the sudden small deviation and not enough time exists to releive the pressure in the strut by the valving system. then the strut is solid and hence the noise..... thats my opinion!

Dario

Post by **sp3ctre** » Mon Jul 16, 2007 10:26 pm

dario wrote:this has happened to me several times and it is generally how you described it. the THUNK is SOOOOO loud that you think the dash is about to detach itself.

IMHO it is the shocks being compressed too fast by the sudden small deviation and not enough time exists to releive the pressure in the strut by the valving system. then the strut is solid and hence the noise..... thats my opinion!

Dario

Well it seems every day is an education for me!.... welcome to the forum Dario!

dario · Post by **dario** » Mon Jul 16, 2007 10:52 pm

sorry forgot to add that when the strut is soid it passes the shock wave directly though the car and thats why it sounds like it does (basically you think that the front of the car has fallen off or the engine is on the floor) its that bad.

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Loud 'thunk' when driving over a small elevation in road

Loud 'thunk' when driving over a small elevation in road