2018 (67) F87 M2 Whirring/Groaning in Corners Off-Throttle

2018 (67) F87 M2 Whirring/Groaning in Corners Off-Throttle

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James-B93

Original Poster:

12 posts

101 months

Saturday 17th August
quotequote all
Evening all,
I’ve been struggling to identify a strange noise my 2018 M2 OG LCI is making when cornering at low speeds when off the throttle.

I can almost always trigger the noise by lifting off the throttle while mid corner. I understand this isn’t how you’d want to drive while on track but I haven’t had the car on track yet so this has only been happening on the road.

So while mid corner at around 20-25mph if I lift off the throttle, even if I was barely on the throttle to begin with, I will hear a low pitch rubbing/whirring noise and I can’t quite pin point if it’s coming from the middle or the rear of the car. In addition to the noise the car will also understeer slightly and I will have to apply further steering lock to overcome this slight understeer.

I have had all 4 wheels off and there is no sign of any of them rubbing on anything.

Sometimes at slow speeds I will hear a grinding noise when turning and pulling out of steep junctions, both facing downhill and uphill.

I have changing the diff oil with genuine BMW oil and it made no difference at all.

Car is on almost new Continental SC7’s and has been aligned. It has also been lowered on Eibach springs however the noise was present before and lowering it hasn’t made any difference.

I’m beginning to think it may be the diff clutch packs but I’m not sure of any method of really proving this. I wonder if the understeer is being caused by the diff trying to lock up the inside wheel, but my real knowledge of this is limited so I am guessing!

I have managed to get a video of the noise which you can hear at about 6s in the video below:

https://youtube.com/shorts/srcm-iKgsp0?si=olg_vnF9...

I’m really scratching my head on this and hoping someone else may have heard something similar and could point me in the right direction

Thanks in advance!

Redline88

519 posts

113 months

Sunday 18th August
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It’s been a while since I sold my m2 but I’m pretty sure there was a section in the manual about this diff noise and it being nothing to be worried about when at low speed.

I can’t hear anything unusual in your clip mate

SmithCorona

729 posts

36 months

Sunday 18th August
quotequote all
If you are referring to the "pestle and mortar" sound that is constant in your video I would vote wheel bearing.

This could be confusing the diff through inconsistant slippage data, and lead to inconsistant power distribution and hence understeer.

But there is definitely a known diff whine/grind on the f87 and f80.


James-B93

Original Poster:

12 posts

101 months

Sunday 18th August
quotequote all
Redline88 said:
It’s been a while since I sold my m2 but I’m pretty sure there was a section in the manual about this diff noise and it being nothing to be worried about when at low speed.

I can’t hear anything unusual in your clip mate
Hmm definitely doesn’t sound normal to me despite what BMW may have put in the owners manual! I get the normal low speed high pitch whine which I could understand and accept
A couple of my mates have F82 M4’s and neither of them have any noises quite like mine makes in the video

James-B93

Original Poster:

12 posts

101 months

Sunday 18th August
quotequote all
SmithCorona said:
If you are referring to the "pestle and mortar" sound that is constant in your video I would vote wheel bearing.

This could be confusing the diff through inconsistant slippage data, and lead to inconsistant power distribution and hence understeer.

But there is definitely a known diff whine/grind on the f87 and f80.
It’s a noise that happens at about 6 seconds in and lasts for a couple seconds. It only happens if I lift off the throttle mid corner, if I keep lightly on the throttle the whole way round, or if I lift off prior to turning in to the corners and coast round at the same speed then i won’t hear the noise and I won’t get this weird understeer

In extreme cases if I really push it I can almost feel the car becoming unsettled, imagine a badly buckled wheel causing a corner of the car to rock up and down

Tempted to just go for a second hand diff off a newer car at this point!

SmithCorona

729 posts

36 months

Sunday 18th August
quotequote all
If there was no swarf in the diff oil change and the wheels are otherwise moving freely I wouldn't rush to a replacement before an afternoon of wheel off trouble shooting.

I would be taking the wheels off, and ensuring all bolts are seated correctly and everything is torqued to spec, and that all of the arms, rotors etc. are in the right place.

Are you certain the ride height is consistent across each axle? And that no bushings have been damaged in the suspension changes?

Also, off topic, but interested to hear experiences with conti 7s, I have only had 3s and 5s in the past and they wore so quickly!

James-B93

Original Poster:

12 posts

101 months

Sunday 18th August
quotequote all
SmithCorona said:
If there was no swarf in the diff oil change and the wheels are otherwise moving freely I wouldn't rush to a replacement before an afternoon of wheel off trouble shooting.

I would be taking the wheels off, and ensuring all bolts are seated correctly and everything is torqued to spec, and that all of the arms, rotors etc. are in the right place.

Are you certain the ride height is consistent across each axle? And that no bushings have been damaged in the suspension changes?

Also, off topic, but interested to hear experiences with conti 7s, I have only had 3s and 5s in the past and they wore so quickly!
Diff oil looked pretty good, nothing obvious pointing towards an issue.

Ride height is consistent across all 4 corners. I have a set of coilovers in the garage ready to fit but I just haven’t had the time yet. Will double check all the bushes when I do the coilovers but when I didn’t the springs I didn’t see anything obvious and I did check but it has been a while!

As for the Conti’s I really rate them. They’re the first set of new tyres I’ve put on this, I had PSSS’s on the front and P Zero’s on the rear when I bought it. PSSS’s were okay but the P Zero’s were literally lethal, and the Conti’s have been really good compared! Would definitely recommend, especially considering their price point

BOR

4,837 posts

262 months

Monday 19th August
quotequote all
There is a BMW additive that can be, er, added to the diff oil to modify the friction.

I would try that before you start pulling everything apart.

James-B93

Original Poster:

12 posts

101 months

Monday 19th August
quotequote all
BOR said:
There is a BMW additive that can be, er, added to the diff oil to modify the friction.

I would try that before you start pulling everything apart.
Don’t suppose you have a part number at all?

When I ordered the diff oil I checked on realoem and it was a part number that superseded an old oil, so I assumed this new oil already had the additive in it

BOR

4,837 posts

262 months

Monday 19th August
quotequote all
I don't I'm afraid.

There are aftermarket products, which are probably the same thing, but I would ask your BMW dealer first.

river_rat

705 posts

210 months

Monday 19th August
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This sounds like an issue I had with my E92 M3 - was bought approved used, but didn't sound good in low speed turns etc - they said it was the diff and was a non-issue but they could add something to the diff oil to quieten it down, which they did and it was fine after that.

mr sagman

1,726 posts

243 months

Monday 19th August
quotequote all
river_rat said:
This sounds like an issue I had with my E92 M3 - was bought approved used, but didn't sound good in low speed turns etc - they said it was the diff and was a non-issue but they could add something to the diff oil to quieten it down, which they did and it was fine after that.
I had exactly this issue with my E92 M3, all it needed was an additive to the diff and it was sorted.
Google E92 M3 diff wine / noises and you will find a ton of discussions all about it.... from memory mine was worse at low speeds / reversing / m3 point turns etc. I would explore this before replacing any parts for sure .

James-B93

Original Poster:

12 posts

101 months

Monday 9th September
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Hi all, thanks for the replies so far.
Driving to work this morning I put the car straight in to Sport+ mode. As it was cold I got a good amount of time without exhaust burbles and I noticed that car does not make the groaning noise when provoked in the same way that it would in Comfort or Sport.
I’m going to test this on my way home by driving in Comfort but turning off the DSC (same as Sport+ just throttle etc in Comfort) to see if it’s related to the DSC.
Does anyone know of anything that might make this a pointless test? I.e. does Sport+ change something in the diff?
Or does anyone know of any reason why this noise might happen in Comfort and Sport but not in Sport+?
TIA

James-B93

Original Poster:

12 posts

101 months

Monday 9th September
quotequote all
On my route home I drove with the car in comfort with one single press of the traction button (can’t remember if that’s DSC or TSC off) and it would not make this weird noise, despite how hard I tried to make it.
Feel like I’m getting somewhere but don’t know enough about what data the car uses to activate the DSC/TSC - whether it’s simply wheel speed or if there’s anything else involved

SmithCorona

729 posts

36 months

Monday 9th September
quotequote all
You were in MDM? Or DSC fully off?

James-B93

Original Poster:

12 posts

101 months

Monday 9th September
quotequote all
SmithCorona said:
You were in MDM? Or DSC fully off?
It’s an OG so it doesn’t technically have MDM mode. It was in TRACTION which I guess is the closest to MDM mode in the M2C/M4 (single press of the traction control button rather than holding it down)

SmithCorona

729 posts

36 months

Monday 9th September
quotequote all
Technically, OG does have MDM, just for some inexplicable reason they chose to write TRACTION on the dash. wink

Regardless, MDM means the brakes are applied less during limited traction - normally they apply to prevent oversteer.

If the only difference between what you are doing is the DSC button then maybe it's a brake issue limited to one side.

Assuming it's not back to the diff oil viscosity issue, for which you can probably solve with the additive...as has been recommended.

James-B93

Original Poster:

12 posts

101 months

Monday 9th September
quotequote all
SmithCorona said:
Technically, OG does have MDM, just for some inexplicable reason they chose to write TRACTION on the dash. wink

Regardless, MDM means the brakes are applied less during limited traction - normally they apply to prevent oversteer.

If the only difference between what you are doing is the DSC button then maybe it's a brake issue limited to one side.

Assuming it's not back to the diff oil viscosity issue, for which you can probably solve with the additive...as has been recommended.
In which case I stand corrected!
I’ve often felt at some slower speeds it feels like the rear is dragging a wheel..I’ve also noticed at higher speeds while not on the brakes that the TSC flashes when I can feel I’m not close to the limits of grip.
I think Carly can show you live wheel speed values but my Carly app is playing up so will likely bite the bullet and move to Bimmerlink and see what I can see in terms of wheel speed and go from there..along with the additive mentioned previously