[dancing__narwhal]

So I've been running 5mm front & 12mm rear spacers on my 328i for the past three months and under all normal circumstances I don't have any issues, but occasionally if I hit a bump or dip at speed I get a pretty bad thud. I can only assume this is the wheel hitting the fender wall.

Specs:
328i non-sport suspension
17x8 style 285 wheels (square setup)
OE spec continental run flats
12mm rear spacers
5mm front spacers

I did some research before buying these and others said 12mm rear would fit, guess that was wrong.

So, any advice? Will going down to 10mm rear spacers alleviate the problem? Or should I just bite the bullet and get the fenders rolled?

[BSM n54iS]

Why can you only assume that? Do you see any damage to your fender/tire..

[dancing__narwhal]

Originally Posted by BdSM n54iS

Why can you only assume that? Do you see any damage to your fender/tire..

That's just it, I've looked several times and cannot detect any significant damage. What else would it be though?

It's probably just rubbing on that "carpeted" lining in the rear wheel well. Mine did the same on 15mm spacers in the rear and went away when I stepped down to 10mm.

After upgrading the struts/shocks, I went back to 15mm spacers in the rear and have never experienced any hint of rubbing ever again.

Moral of the story; stock dampers are crap, even with relatively low miles on them. Change them out and feel a world of difference....among other benefits.

[feuer]

dgaultiere you have LCI (at least I think so) and have 8mm wider track than pre LCI so you need 10 or 12mm spacers in the rear.

[BM3Rrrr]

Originally Posted by FCobra94

Moral of the story; stock dampers are crap, even with relatively low miles on them. Change them out and feel a world of difference....among other benefits.

+1 for that.

I cant see how 12mm spacers on 17x8 wheels with non sport suspension rubs at all.

This sounds like a suspension issue more then a spacer issue.
Long term get some Koni's cause it sounds like your shocks are effed
Short term, remove the 12mm spacer
Shorter term, stop driving over bumps/dips at speed.

[dancing__narwhal]

Thanks guys. Yes my car is LCI so I have the wider rear track. Car only has 50k miles so do you really think the dampers are bad? The car feels fine most of the time it's only certain bumps that give a thud.

I did recently learn that my thrust arm bushings are worn so I suppose that could be a factor. Planning to replace those with the M3 part soon.

[dancing__narwhal]

Thanks guys. Yes my car is LCI so I have the wider rear track. Car only has 50k miles so do you really think the dampers are bad? The car feels fine most of the time it's only certain bumps that give a thud.

I did recently learn that my thrust arm bushings are worn so I suppose that could be a factor. Planning to replace those with the M3 part soon.

[dancing__narwhal]

Thanks guys. Yes my car is LCI so I have the wider rear track. Car only has 50k miles so do you really think the dampers are bad? The car feels fine most of the time it's only certain bumps that give a thud.

I did recently learn that my thrust arm bushings are worn so I suppose that could be a factor. Planning to replace those with the M3 part soon.

Originally Posted by dgaultiere

Car only has 50k miles so do you really think the dampers are bad?

Well, that depends; if by "bad" you mean they render the car undriveable, then no, they're not bad.

If by "bad" you mean they're a flaming pile of underdamped rubbish, then yes, they're bad.

[The Nightman]

I could be wrong but I don't think you're rubbing. From my experience, rubbing sounds more like a scraping noise rather than a thud. There would also be signs of rubbing in the wheel well liner too. Not to mention that rubbing with 12mm spacers on 17x8 ET34 and non-sport suspension seems highly unlikely.

I'll be getting 15mm spacers for 284s (also 17x8, ET34) on my non-sport E90 LCI and will report back.

Originally Posted by freedomfries

I could be wrong but I don't think you're rubbing. From my experience, rubbing sounds more like a scraping noise rather than a thud. There would also be signs of rubbing in the wheel well liner too. Not to mention that rubbing with 12mm spacers on 17x8 ET34 and non-sport suspension seems highly unlikely.

Sure, if he's rubbing on the fender itself it would "scrape" and gouge the tire...if he's rubbing on the internal liner (especially in the rear) a thud isn't out of the question.

12mm + LCI + etc...every car is different.

Best way to find out is to park one rear wheel on an incline to statically drive the tire up as high as it'll go into the wheel well. Should be easily able to tell what's going on after that.

[refugeeofwar]

You need to know the offsets of those wheels. I ran 15mm spacers in the back of my LCI E92 for years without issue with the stock sports package 18x8 ET34 front and 18x8.5 ET37 rear. Only way it rubs is if you put a wheel on there with a smaller offset than stock AND then added spacers. The 37mm offset with my stock wheels plus a 15mm spacer had plenty of space. I now run 18x9 ET25 and they also fit great.

[feuer]

refugeeofwar style 285 are 17x8 et34 so with 12mm spacer will come to et22

[dancing__narwhal]

Thanks for all the help guys. I'm going to try the parking on an incline idea and see what I get.

Here are some pics of the wheel and fender:

Yeah, I could totally see that setup rubbing on stock suspension...looking forward to seeing what you notice after parking on a slope.

[Antetokounmpo]

Originally Posted by dgaultiere

Thanks for all the help guys. I'm going to try the parking on an incline idea and see what I get.

Here are some pics of the wheel and fender:

Ya that'll rub. If you have access to a lathe or know somebody who does you can take a few mm off to prevent rub. I took my 20mm down to 18mm on a lathe, very easy and takes just a few min.

[dancing__narwhal]

FYI, I have tried raising the rear wheel on a curb a few times and have not seen any rub. I've also been paying closer attention to the noise when driving and I really don't think it is rubbing.

It's really weird because it doesn't happen at lower speed, even over big speed bumps. It only seems to happen at speeds over 20mph and even if the bump is relatively small (e.g. manhole covers). It's also hard to tell if it's coming from the front or the back but I'm starting to think it's actually the front.

I'm fairly convinced it has to do with my worn front thrust arms as I was told by my indie shop they needed replacing and I can tell that the steering is a bit sloppy right now. I'll see if I can get a picture of the car with a tire raised.

[The Nightman]

Originally Posted by freedomfries

I could be wrong but I don't think you're rubbing. From my experience, rubbing sounds more like a scraping noise rather than a thud. There would also be signs of rubbing in the wheel well liner too. Not to mention that rubbing with 12mm spacers on 17x8 ET34 and non-sport suspension seems highly unlikely.

I'll be getting 15mm spacers for 284s (also 17x8, ET34) on my non-sport E90 LCI and will report back.

Now running BMS 12 and 15mm on my E90 LCI with 284s (17x8, ET34) and standard suspension (69k mi) and there is no rubbing whatsoever. Something else is going on, as you suspect

[patsbimmer1]

As others have stated I don't think it's rubbing. FWIW I'm running a 265/35r18 on style 162 in the rear with a 12mm spacer and lowered with no rubbing.