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Knocking noise, Im at my wits end - please help

Posted: Tue Feb 16, 2016 9:24 am
by Dirty Boy
I would appreciate any suggestion here, this is driving myself and the mechanic to murder.

The vehicle: Gen3 2006 LWB 3.2 GLS 165k km - No modifications

Recently it developed a knocking noise from the front. This happens when one brakes (one solid 'thunk') or when you accelerate (again, one solid 'thunk')
The shock are the originals so I was planning on changing them anyway. Now I had a reason.

Sent it to a local indi

New shocks fitted (std KYB)
Upper ball joint on wishbones replaced.
Noise still there. Sent back.
As per the advise on this forum
The 4 (I think) little donut bushes on the Engine support cross member replaced. Noise still there.
Stabiliser bar drop links replaced. Noise still there.

Mechanic has gone over vehicle with a crow bar and cannot find anything else that is overly loose.

Noise seems to only happen with fore/aft movement of the engine. I am also noting it when turning at parking speed.
If it was engine mountings, Im sure you would hear it just revving the engine.
Its not a rattle like brake calipers. I did the last set of brake pads and know that all the anti rattle springs are in place.

Suggestions please.

Re: Knocking noise, Im at my wits end - please help

Posted: Tue Feb 16, 2016 11:29 am
by peterpot
I had a very small and occasional random "tok" on my gen3 when I braked hard at slow crawl only going forward. I searched high and low and tried everything. It never got worse and I think I might have gotten used to it or it went away.
My wife had a Golf which also had a loud thunk when you braked moving forward. I searched high and low. One day I was changing the oil and went and got a very big power bar and one by one loosened and then tightened all the big crossmember bolts. One bolt was tight and I could easily have left it. I loosened it with a crack and 1/2 a turn. I knew I had found it when it turned a full turn to tighten again and yes when test driven the knock was gone. You must loosen and retighten. Even try removing and lubricating before tightening again. Good luck.

Re: Knocking noise, Im at my wits end - please help

Posted: Tue Feb 16, 2016 12:00 pm
by Dirty Boy
Thanks Peter
I will do that too. This is too loud and irritating to leave it, so something has to be done.

Re: Knocking noise, Im at my wits end - please help

Posted: Sun Feb 21, 2016 6:11 pm
by Gords
Hi
3 things to look for...
1. Look at the upper shock turret mountings/ bearings.
2. Check anti rollbar bushes, they go hard and not even a crobar will show it up.
3. Exhaust mounting rubbers and mount onto gearbox
Could also be rear stabiliser bar that sounds like its coming from the front.

Last but not least is calliper bushes are worn, common problem that is overlooked.

Re: Knocking noise, Im at my wits end - please help

Posted: Sun Feb 21, 2016 7:27 pm
by Dirty Boy
Thanks Gords, its going back in tomorrow so I will add your points to the list for the mechanic.

Re: Knocking noise, Im at my wits end - please help

Posted: Mon Feb 22, 2016 7:57 am
by martin111
Hi,
I have the same 'metallic knock' just before you come to standstill.
It comes and goes, but back again now after fitting new discs and pads.
None of the dealerships have been able to fix it.
I think Gords might be right, nobody looks at the top of the shock turrets, as you have to remove the battery on one side and air filter on other side, too much work.

Re: Knocking noise, Im at my wits end - please help

Posted: Mon Feb 22, 2016 6:27 pm
by Gords
Any news on that knocking noise ?

Re: Knocking noise, Im at my wits end - please help

Posted: Mon Feb 22, 2016 9:07 pm
by Dirty Boy
Not yet Gords but we might be onto something. The mechanic said that the noise had gone when he disconnected the drop links. He assumed that they were the problem so replaced them. This means that it well be the rubber bushes on the stabiliser as mentioned by a few other owners.
I imagine you can only get them from Mitsu so may have to wait a while.
I will post here when I get it all resolved. There is nothing worse than following a thread and never finding out what the solution to the problem was.

Re: Knocking noise, Im at my wits end - please help

Posted: Thu Feb 25, 2016 10:07 am
by Dirty Boy
Ok, some feedback. I am running out of funds :oops:

Sorry, that's not what you want to hear. You want the technical stuff.
I gave my list of possibilities to the mechanic and he told me that a while back he disconnected the anti sway bar and the noise went away, so he replaced the drop links.
Of course the noise was still there when I picked up the car. I told him that consensus is the rubber bushed. So this time he completely removed the ASB. Last night he told me take the car home and try it out. he thinks the noise has gone but there seemed to be another noise. I picked up the car and down the road tried some aggressive braking and pull off and the 'thunk' seems to have gone. I then crawled along in the traffic listening out for this other noise. Got onto the freeway and at 80km/h all hell broke loose, I thought the wheel was going to come off. Crawled home with this cyclic cloncking. Limped back to workshop this morning. Pretty sure its a CV joint.

Now it beats me, but is this just coincidence because there is no way the two noises could be related ? The original noise was from the fore/ aft movement of the engine. CV joints/this latest noise is wheel rotation linked.

Its just money I keep telling myself.

Re: Knocking noise, Im at my wits end - please help

Posted: Wed Mar 02, 2016 12:13 pm
by Dirty Boy
Ok, so more feedback

The D bushed on the Anti Sway bar were replaced and there is still a knock.

The CV joint noise was exactly that. It wasn't because it coincidently bombed out at the same time as all these other issues. It was because the guy working on my car, loosened the nut at the end of the drive shaft and forgot to retighten after doing all the work underneath. As a result the CV joint had some play in it. That is now sorted.

So I still have the original thud to deal with. Going to live with it for a while then see if Haydn can assist because the current workshop is only working off info I give them. I need someone who knows there way around a Mitsu.

To crown it all, Friday night we got hit by a massive storm and I now have hail damage. :cry: Gutted !