Just fitted powerflex dogbone bushes, and NOW i get knocking on hard acceleration!!

[daddycool]

i've read about people having the knocking sound under hard acceleration and replacing the dogbone bushes to fix the problem, but never the other way round!!

gear change is alot smoother now, but it's developed the knocking noise. is it a case of the now stiff dogbone bush has shown up a weakness in the other mounts?

dogbone has been fitted correctly per info from multiple threads on this forum, and bolts torqued up correctly. it doesn't knock on, say, 75% throttle.

thanks, kris

 

[Ol’ Tarby]

Re: Just fitted powerflex dogbone bushes, and NOW i get knocking on hard acceleration

Ye possibly other mounts worn mate. Wen mine started knocking I loosened off the top engine mount, pulled the engine as far forward as the mount would allow and tightened it back up, and its never knocked since. So just try that before ya spend on other mounts

 

[k16v]

Re: Just fitted powerflex dogbone bushes, and NOW i get knocking on hard acceleration

i had the same problem. the mount under the battery tray could be loose or even the bolt that goes into that mount has to parts to it tightin up everything

 

[daddycool]

Re: Just fitted powerflex dogbone bushes, and NOW i get knocking on hard acceleration

the bracket was already all the forward, one of the small pins stopped it going any further. just to check what i'm aiming for, i want the rear bumper (on the right in the picture, not arrowed) to be up against the bracket thus preventing any backward movement- correct?

 

[Ol’ Tarby]

Re: Just fitted powerflex dogbone bushes, and NOW i get knocking on hard acceleration

ignore lol

 

[Andyman]

Re: Just fitted powerflex dogbone bushes, and NOW i get knocking on hard acceleration

the bracket was already all the forward, one of the small pins stopped it going any further. just to check what i'm aiming for, i want the rear bumper (on the right in the picture, not arrowed) to be up against the bracket thus preventing any backward movement- correct?
View attachment 42981

Stock mounts dont hold the engine rigid even when new

 

[daddycool]

Re: Just fitted powerflex dogbone bushes, and NOW i get knocking on hard acceleration

pulled it all the way forward and still knocking. took the bush out and looks in good condition. i need to check the gearbox mount when i pick up some new sockets next week.

i had a look at what causes the knocking and you can see how close the bottom of the manifold is to the subframe, you cant even get a finger in there.

assuming the bushes are all good, is it unwise to raise the engine a couple of mm by using a shim or washers under the mount itself, or does the engine sit perfectly level when its standard?

other than that, it's either go back to standard dogbone, or pay up for the ktec engine and upper gearbox mounts.

 

[matt5687]

Re: Just fitted powerflex dogbone bushes, and NOW i get knocking on hard acceleration

I would just go for the K-Tec uprated mounts. When my standard mounts went I pulled the engine forward but found it still to be knocking so just shelled out for the uprated ones. One of the best purchases I made tbh. Great product. Whole car felt solid and the power was instant.