Knocking Sound On Speed Bumps

[Hogmahub]

After 8 years of driving a Celica GT4 I'v ejust picked up an imported Supra SZ. Its a 1993 model, in great condition, 52k miles, the engine is quiet as anything and pulls really well. The only thing is when I hit a bump in the road or go over a speed bump I get a knocking sound. Hard to pin down where it is coming from.

What are the likely causes of this?

Is it more likely to be suspension or something simple like a missing bracket on the exhaust?

Any help to a non mechanically minded, Supra newbie very much appreciated

Thanks

[215 compressor]

After 8 years of driving a Celica GT4 I'v ejust picked up an imported Supra SZ. Its a 1993 model, in great condition, 52k miles, the engine is quiet as anything and pulls really well. The only thing is when I hit a bump in the road or go over a speed bump I get a knocking sound. Hard to pin down where it is coming from.

What are the likely causes of this?

Is it more likely to be suspension or something simple like a missing bracket on the exhaust?

Any help to a non mechanically minded, Supra newbie very much appreciated

Thanks

it sounds like anti-roll bar drop links .turn wheels in lock and try push the link on anti roll bar up and down slightist play can cause a knocking noise .somewhere to start welcome to TOC

[adi]

all mkiv's have a huge can of lynx africa stored in the glovebox.. i'd start there.

[Hogmahub]

all mkiv's have a huge can of lynx africa stored in the glovebox.. i'd start there.

Thought you were on to something there when I found Hai Karate and Brut, but unfortunately removing them only improved the ambience. :P

Down to the garage me thinks - let you know what it is when I know more!

[Karma Supra]

Good call Adi ;)

It might be worth checking the sub frame bolts are all tight if the ARB linkages are all good....

[Hogmahub]

Good call Adi ;)

It might be worth checking the sub frame bolts are all tight if the ARB linkages are all good....

OK - had the ARBs replaced and its not done anything! I'll look at the sub frame bolts now :)

Mechanic is suggesting we look at the top and bottom wishbone and the shocks. Any views as to which one is worth trying first / any quick ways to eliminate either without taking the car apart?

Any suggestions gratefully received - have a good break!

[Leeky]

Few possibilities

Loose suspension top mounts

worn top mounts

lower subframe bolts

loose front brake pad (caused the same thing you describe above on one of my mk4 supras)

worn roll bar drop links

ball joint

blown shock

;)

If i was you i would jack it up and wiggle everything to test for play.

[Hogmahub]

The mechanic has had a look and found that all the suspension seems good at the front. At the back the drop links are worn as is one of the wishbone bushes. He says that even though the noise seems to be coming mainly from the front off side, it might be caused by the back?!

Any views on that one?

Thanks

[djbutler]

The mechanic has had a look and found that all the suspension seems good at the front. At the back the drop links are worn as is one of the wishbone bushes. He says that even though the noise seems to be coming mainly from the front off side, it might be caused by the back?!

Any views on that one?

Thanks

Had exactly the same with my 93 at 50,000, Jap shocks, hard as hell, changed for KYB AGX gas shocks and it transformed the car and cured all the knocks at the same time. Turned out two shocks on opposite corners were knackered. £340 well spent (changed them myself).