Intermittent rattle!

dunks · Post by **dunks** » Tue May 08, 2018 9:34 pm

Without wanting to hijack the other thread on this subject I thought i'd create another one.

A few days ago my Z4 E85 2.5 seems to have developed an intermittent tinny rattle/scraping noise, it might be coincidence but it seems to have happened after slightly bumping the underside of the car reversing down a steep dropped kerb.

It seems to be brought on when going over small bumps or just a rough road surface, and is quite tinny in nature. If I lift off the throttle the noise seems constant and seems to be more of a scraping noise in sync with the wheels rotating, and even persists when the road surface smooths out perfectly.

Seems to be coming from the drivers side rear also.

Sometimes going over another bump seems to stop the noise, and I'm not 100% sure but applying the brakes sometimes stops it as well.

Any ideas?

wonkydonkey · Post by **wonkydonkey** » Tue May 08, 2018 10:04 pm

Could you perhaps have dislodged a brake dust shield or exhaust heat shield? If an exhaust heat shield is rattling it will normally be rattling against the exhaust. Try hitting your tailpipe with your hand and listen out for the rattle.

patriot66 · Post by **patriot66** » Tue May 08, 2018 10:10 pm

Check the brake disc backing plate. They are quite flimsy and on the rear they fit over the edge of the disc very snugly.

Post by **srhutch** » Wed May 09, 2018 7:00 am

Check your rear springs haven’t snapped.

Very common issue.

dunks · Post by **dunks** » Wed May 09, 2018 8:33 am

Springs were on the list, but it's not always when over bumps.

Driving in this morning it was quite loud, and constant, at low speed on a smooth surface. More of a scaping noise than a rattle.

dunks · Post by **dunks** » Wed May 09, 2018 8:09 pm

Had a look underneath (not jacked up, so tricky) and it seems the middle section of the exhaust heatshield is loose in a few places.

Reckon this would be a likely culprit? Seems odd it makes a noise over bumps and sometimes a continuous rattle/scrape noise.

But upon looking underneath the car it seems I have bigger problems.

Had an inspection 2 a few months ago and the garage said the oil drain plug looked like it'd been threaded before and was leaky, he had a bit of a time getting it back in but get there in the end, and just said to keep an eye on it. Oil level seemed fine until a day or so ago where it looked a bit low, needed maybe 1L at most to bring it back up to level.

patriot66 · Post by **patriot66** » Wed May 09, 2018 8:14 pm

Glad you seem to have found your rattle but that oil leak is quite worrying

dunks · Post by **dunks** » Wed May 09, 2018 8:51 pm

Tell me about it

dunks · Post by **dunks** » Sun May 13, 2018 9:06 pm

Little update, the front offside brake dust cover is loose and creating quite a noise, I reckon this is the source of the noise as even though the heat shield is loose it's pretty light and would take a lot to flex and rattle against the underside of the car.

Seems it's a pain to replace, need to remove the disc and bearing!

Scooba_Steve · Post by **Scooba_Steve** » Sun May 13, 2018 10:22 pm

Cable tie it as I have done! I'm hoping someone can make up a two piece version... stupid design to have to take off a wheel bearing.

dunks · Post by **dunks** » Mon May 14, 2018 3:24 pm

Scooba_Steve wrote: ↑Sun May 13, 2018 10:22 pm Cable tie it as I have done! I'm hoping someone can make up a two piece version... stupid design to have to take off a wheel bearing.

I've read a few posts from people saying they've cable tied it, what do you attach it to?

Is it still a wheel, calliper and disc off job?

Scooba_Steve · Post by **Scooba_Steve** » Mon May 14, 2018 5:48 pm

To tie it you could probably get away with not taking the disc off, but I did. Drilled a couple of holes and tied to the shock or bracket. Failing that you can cut it off! There is no way I'm pulling a hub for the sake of it just in case it turns into an epic ballache!

If I get replacements then I might cut them to get round the hub then bolt them back together. Stupid design.

dunks · Post by **dunks** » Mon May 14, 2018 9:23 pm

Scooba_Steve wrote: ↑Mon May 14, 2018 5:48 pm To tie it you could probably get away with not taking the disc off, but I did. Drilled a couple of holes and tied to the shock or bracket. Failing that you can cut it off! There is no way I'm pulling a hub for the sake of it just in case it turns into an epic ballache!

If I get replacements then I might cut them to get round the hub then bolt them back together. Stupid design.

Cool, will have to have a look sometime. Don't have a jack/axel stands though, might see what I can do with the wheel on full lock...

Seems a stupid design, you think they'd make the protectors C shaped or something so they can slot over the shaft/hubs!

Scooba_Steve · Post by **Scooba_Steve** » Mon May 14, 2018 10:00 pm

dunks wrote: ↑Mon May 14, 2018 9:23 pm Seems a stupid design, you think they'd make the protectors C shaped or something

Tell me about it

dunks · Post by **dunks** » Tue May 15, 2018 1:57 pm

Scooba_Steve wrote: ↑Mon May 14, 2018 5:48 pm To tie it you could probably get away with not taking the disc off, but I did. Drilled a couple of holes and tied to the shock or bracket. Failing that you can cut it off! There is no way I'm pulling a hub for the sake of it just in case it turns into an epic ballache!

If I get replacements then I might cut them to get round the hub then bolt them back together. Stupid design.

Seems there's a small hole (5 mm dia) at the top of the shield in the center, I reckon I could zip tie to the shock using this hole.

But will zip tying it to the shock work? Doesn't the brake shield pivot with the wheel, so it'll move relative to the shock and snap the tie?

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