Knocking sound when turning right!

[BigDaddy]

Hello everyone. Been slowly working through some bits and bobs on my new (to me) Z. After getting new tyres fitted today I finally felt a little bit more confident in the car as I bought it with 9 yr old tyres which were cracked so I have been driving it pretty gently. Anyway got some new pilot sport 5s and felt great for about a minute until I went round my first roundabout at a decent pace and heard a knocking noise from front near side wheel. It’s a repeated knock not just a single clunk and I can feel it through the steering wheel. Doesn’t happen if I go slow, but if I give it a bit of welly then it repeatedly knocks.

Going to get it on axle stands tomorrow, but what should I look at first?

Cheers!

[Huz-z]

I had a similar issue with my 2006 SI while backing up with the steering turned hard to the right. Turns out that the fix was to tighten the nuts at the end of the two support struts under the hood. They run from the Center of the firewall to the top of each front wheel shock tower. If you try this, be careful not to over tighten them. Perhaps someone here will know the correct torque . Good luck!!

[colb]

Check all ball joints and sway bar rubber bushes for wear and movement also check out the suspension top mounts are tight with no play to cause a knock. Replace any that are found wanting. Also check out the two bars under the bonnet as @Huz-z mentions in his post.

[enuff_zed]

I had a similar issue with my 2006 SI while backing up with the steering turned hard to the right. Turns out that the fix was to tighten the nuts at the end of the two support struts under the hood. They run from the Center of the firewall to the top of each front wheel shock tower. If you try this, be careful not to over tighten them. Perhaps someone here will know the correct torque . Good luck!!

Three white knuckles

[BigDaddy]

Will get on it in the morn when I have some light. I suspect there are some worn bushes there so I’ll be asking for more advice on how to replace some bits and bobs I'm sure! I did buy a fixer upper that hadn’t been driven much in the last few years so not too surprised there are a few bits that are worn.

Thanks for replies, will give it a through going over and as Arnold says I’ll be back…

[Zedebee]

You may have a broken spring

[Huz-z]

If you go to this thread look for the February 2 2009 post by the late Ron Stygar who posted a chart citing 41 Nm:

https://www.bimmerfest.com/threads/z4-d ... tby=oldest

[Rockhopper]

Check that the stick on balance weights are not hitting the brake calliper (been there - done that).

[Mike6]

My money would be on the drop links . Cheap and simple fix but make sure you buy HD ones (think that is what they were) as they are much stronger , they take a bit of a bashing on our potholed roads.

[BigDaddy]

Thanks for replies everyone.

I’ll take the wheels off and check the drop links with a bar tomorrow. I put it up the ramps today for a good look underneath and couldn’t see anything wrong with a lot of pushing and pulling but to be fair it would have to be really loose to show up with only hand power and the knocking only happens if I’m giving it some welly round a corner, if I’m driving slowly it doesn’t happen. I did check the struts and they seem to be tight and checked the wheel weights too and they weren’t hitting the calipers. It feels like it’s coming from the wheel rather than anywhere else so it doesn’t feel like the strut but hey how do you know really when you’re driving where a knock is coming from. Anyway will get the wheels off tomorrow and give it a better look.

[Rockhopper]

Drop links only knock on bumpy roads.

[BigDaddy]

Yeah it’s fine on bumpy roads driving forwards. The knocking only happens when I turn right at speed, like if I try going round a roundabout reasonably quickly or I swing it into my drive. If I drive like driving miss daisy it doesn’t happen. I don’t need to be driving like a loon, just giving it a little bit of oomph and then it happens.

[BigDaddy]

Have had the car in to a mechanic who did hear the knocking but couldn’t find where it was coming from. I’ve tightened up the strut braces and the top strut nuts. It’s made no difference. The car doesn’t knock at all when driving straight but a hard pull to the right will make it knock repeatedly.

If it was a front wheel drive car I’d have said cv joints and that’s what the mechanic said he thought it felt/sounded like too but the steering rack is not loose.

I have been doing some other bits and bobs with coolant and oil leaks, which I think(hope) have been sorted now but am at a bit of a loss with this one and could do with another opinion on it really as I feel a bit nervous driving it with any gusto in case something gives way. Am in Nottingham. Anyone in the midlands that knows Zed suspension well and could offer any advice?

[enuff_zed]

Speak to bigwinn. He’s in Lincoln.

[Zedebee]

Check there’s no rubbing marks under the wheel arch. Changing the tyres may just have pushed up your rolling radius to the limit, particularly if you’re on lowered suspension or running spacers. The tyre could just be catching the arch liner on full lock.