[ZPrime]

^^ I hate photobucket so much. That image is hard to read. Any chance you can upload the full resolution to something like imgur?

[M2OG]

Today the tech swapped the diff with a new one, I will know tomorrow if it's the cause. He did mention that the diff was overfilled at the 1200 mile service and while the part number on the work order was correct he did suspect it was the wrong fluid.

[Egress]

Originally Posted by Natek

Today the tech swapped the diff with a new one, I will know tomorrow if it's the cause. He did mention that the diff was overfilled at the 1200 mile service and while the part number on the work order was correct he did suspect it was the wrong fluid.

How could it have been overfilled? These oils come in 1 Liter bottles from BMW and exactly 1 Liter is what you need for this diff...

[M2OG]

Originally Posted by Egress

How could it have been overfilled? These oils come in 1 Liter bottles from BMW and exactly 1 Liter is what you need for this diff...

I have no idea, maybe thats why he's suspect of the break in service to begin with?

[Tumbleweeds78]

Originally Posted by Egress

How could it have been overfilled? These oils come in 1 Liter bottles from BMW and exactly 1 Liter is what you need for this diff...

Not necessarily true. Many dealerships order fluids in 55 gallon drums and dispense them as needed.

[M2Nebula]

Originally Posted by Tumbleweeds78

Not necessarily true. Many dealerships order fluids in 55 gallon drums and dispense them as needed.

Correct, but normally just engine oil is purchased in bulk/drums because it is used in much higher volume due to more frequent service intervals and commonality. If billed/invoiced this way the BMW part number should show three additional numbers at the end to indicate it was dispersed in tenths (0.1) of a gallon.

This is not to say that some dealers don't choose to stock gear oil this way as well. My service invoice shows qty 3 so this would make sense if it was added from bulk equaling 0.3 gallon. Pumping 3 liters in there wouldn't make much sense, it would be pouring out the filler hole and you would have to throw the plug back on very quickly. Somehow this wouldn't surprise me though. I may just loosen the fill plug and check it.

[lax01]

Originally Posted by Natek

Today the tech swapped the diff with a new one, I will know tomorrow if it's the cause. He did mention that the diff was overfilled at the 1200 mile service and while the part number on the work order was correct he did suspect it was the wrong fluid.

ugh...which dealer was this (and which dealer did the original 1200 mile service)?

[M2OG]

the plot thickens. New diff and yet the sound persists. Trying to find another manual M2 to compare back to back.

[rich8566]

Originally Posted by lax01

ugh...which dealer was this (and which dealer did the original 1200 mile service)?

How can a diff be overfilled? Doesn't any excess drain out of the fill hole?

[rouxeny]

Oh boy, the wrong diff oil was a huge problem early in the E9X run.

Hope this gets sorted out.

Somewhat not related, what floor mats are those?

[M2OG]

Originally Posted by rouxeny

Oh boy, the wrong diff oil was a huge problem early in the E9X run.

Hope this gets sorted out.

Somewhat not related, what floor mats are those?

They're the BMW "all weather" rubber floor mats available for the 2 series.

[doug_999]

Just to confirm, have you put the oem tires/wheels back on?

[OG///M]

Originally Posted by doug_999

Just to confirm, have you put the oem tires/wheels back on?

^This. When all fails, return to the original setup.

I find this situation surprising when all you did was change tires.

It could have been that the vibration/sound was already there and the new tires amplified it.

This car makes a lot of weird sounds being all hardcore bolted on and all but certainly not that loud and that consistently.

Judging by the speed you were going, 3-4mph which is basically idling in first gear and letting the car roll, and the frequency of the sound as you speed up just by even a little, it might have something to do with the driveshaft rotation. Not a mechanic, just observation.

[M2Nebula]

Originally Posted by rich8566

How can a diff be overfilled? Doesn't any excess drain out of the fill hole?

Guess if you really tried you could pump in the fluid more quickly than it can leak out due to high viscosity, and then screw the plug back on faster than the six million dollar man!

[M2joey]

Originally Posted by rich8566

Your oversized tires are rubbing on the struts.

I did the same 255/275 4Ss, not an issue at all. You can go bigger on the OEM wheels as well, do some investigation.

[M2OG]

Hey everyone, the verdict is in. A friend who also has a manual M2 with michilen's was nice enough to bring his car to the dealer so he and the tech could compare. The same phenomenon was observed but at a lower volume. That said, I am running M3/4 sized tires so the increase in volume is thought to be the byproduct of the 10mm wider tires.

The tech still thinks it's weird and ultra specific as it doesn't happen on the M3/4 and he also tried 18s off another M3 and the noise was still present. A rep from BMW NA will be shown the car this afternoon.

[CSN]

Originally Posted by Natek

Hey everyone, the verdict is in. A friend who also has a manual M2 with michilen's was nice enough to bring his car to the dealer so he and the tech could compare. The same phenomenon was observed but at a lower volume. That said, I am running M3/4 sized tires so the increase in volume is thought to be the byproduct of the 10mm wider tires.

The tech still thinks it's weird and ultra specific as it doesn't happen on the M3/4 and he also tried 18s off another M3 and the noise was still present. A rep from BMW NA will be shown the car this afternoon.

So it is normal? I have all stock with Pilot SS's. Same thing. I wont be taking it in. It is not a huge issue it just sounded a little off.

[M2OG]

Originally Posted by CSN

So it is normal? I have all stock with Pilot SS's. Same thing. I wont be taking it in. It is not a huge issue it just sounded a little off.

Yup, deemed normal operation of the tires. Annoying but I can live with it.

[crqflier]

Just one more reason Contis > Mich...

[Stephbaker]

Originally Posted by Natek

Hi everyone,
Recently swapped the stock Continental tires for Pilot Sport 4s and have noticed that at exactly 3-4mph I get a noticeable "whomp whomp whomp" kind of sound, seemingly from the back of the car but thats difficult to determine. I shot a quick video to get the sound.

I can't be certain about when I started hearing it, so it might not be the tires at all. I'm posting here to see if anyone has a similar experience before I put the car on jack stands.

Thanks!

Tires are designed for comfort and not fashion, with lower noise and fuel technology and maybe sometimes for the looks. But when a lot of people switch the tires for others, they need to first look if the tires can carry the stress and weight. So if we do switch them, maybe we can try looking for something similar recommended by the manufacturer or get similar tries that can fit the description for your car or truck. I guess sometimes we should read up before. My brother really ruined his truck tires when he wasn't paying attention and replaced them for something that wasn't recommended. Hence, I think we should also pay attention to the make of our tires, like for example tires need carbon black for durability but with the carbon black market being so huge we can get low quality carbon black in our tires for cheap prices that can really be not worth the money. So please be careful when you buy car tires.