Highway driving and a whining

[gettinOld]

14 28i xdrive w/ 50k miles

Lately, I have been noticing a sharp whine coming from what I'm guessing is the center diff. It's very faint, but when im cruising on the highway around 70mph is when I can start to hear it over the wind and road noise. Its not a LOUD noise by any means but I don't believe a normal soccer mom or non car enthusiast would pick it up in a normal situation, especially with the radio on. Is this normal for these cars? Anyone else experience this? Car hasn't skipped a beat at all.... should I take action and have some preventative measures done? Thanks.

[Gamb1t]

Could be your transfer case acting up. If you can hear the whine at that speeds over the wind noise etc. then it's abnormal. How about at slower speeds? Revving it up at idle?

Bring it in be it BMW dealership or indie shop.

[gettinOld]

I hear it when the car is decelerating from a higher speed. Like I mentioned if some other person is in the car they wouldn't even hear it or know it was happening. It's an "enthusiast" type of thing where we all hear the smallest strangest noises....

[0w40X1]

Known trouble with the X1 xdrive; the front transfer case can leak, whine, need rebuilt, etc.

Also, check and make sure tires are same wear depth all around.

It might be possible to stop noise by rotating tires front to back.

It sounds like the fronts are slowing more than the back on decel so it whines.

Rears should be slightly smaller slowing down more.

[gettinOld]

Copy that. I'm staggered with the 225Ms as it is an M Sport. I guess I have to measure tire depth. So I have to change all 4 tires when the rears disappear after 10k miles? I don't drive spirited either and I can't stand the RFT.

[gettinOld]

btw.... Thank you for the responses gentlemen! I was under the car the other day changing oil and I did not see any fluid leaks at all.

[0w40X1]

Originally Posted by gettinOld

Copy that. I'm staggered with the 225Ms as it is an M Sport. I guess I have to measure tire depth. So I have to change all 4 tires when the rears disappear after 10k miles? I don't drive spirited either and I can't stand the RFT.

If you are staggered the 2 different sizes are a close match not exact.

Maybe you Xdrive guys can find out which pair needs to be larger and slower turning.

I suspect the fronts should be.

So, on my staggered s28i with 8x 18 and 9x18 355m wheels, I'd put Michelin PSS of 225/45r18 (25.9 inch diameter) and 255/40r18 (26.0 inch diameter) if I stayed same as stock without run flat.

I'm gonna down gear approx 4% with 225/40r18 PSS (25.1 diameter) and 255/35r18 (25.0 diameter).

Notice the stock sizes have the front tires rolling slightly faster, while the lower profile set I'm putting on has the front tires rolling slightly slower.

[Gamb1t]

Sure it's not the turbo whistle?

Not sure your car's mileage, but it's good to change the TC oil out if you haven't. It's tricky but not super hard.
Based on realoem, I deduced the BMW had a few revisions of the TC over the years.

[Musiclover1013]

Saw your post. I just had to have my front differential replaced due to the same sound. My 2013 X1 has 51,000 miles on it. Just noticed a whining sound late last week that only happened on deceleration at speeds 75 down to about 64. Thank God for my CPO warranty as the damage would have been about $2,900. My dealer said that this was the 2nd one they've replaced in the X1 in about 30 days. Good Luck.

[der_kommissar]

I had that sound in my '15 x28i earlier this year and had the transfer case replaced under warranty. Get it in ASAP and hope you can get it done under courtesy from the dealer.

[gettinOld]

Over 50k unfortunately.....

[der_kommissar]

If you are close to 50k and have a good relationship with your dealer, sometimes they will help you out anyway. Can't hurt to ask.

[Seagull]

Let us know how it goes! Hope it isn't too costly!

[mhx]

Could be a wheel bearing too. You can self check this at home by putting it on a jack stand and try to wobble the wheels

Sounds like a bad tired or a whooosh whoosh sound.
Also check your center diff as stated above.

prob one of the 3:
1. tires
2. wheel bearing
3. xdrive diff

[gettinOld]

not a wheel bearing.

[kiloTHREE]

Huh, just for giggles I priced out a new transfer case. Just a shade under 1k, so not too bad. That's not even reman'd, brand new.

[gettinOld]

well that's a relief to know.... i haven't heard the noise getting any worse, which is good news.

If you've ever heard a 911 GT3 Cup or any of the 911 based racecars, the transmission snouse is very similar to what I hear just not nearly as loud.

[kiloTHREE]

Originally Posted by gettinOld

If you've ever heard a 911 GT3 Cup or any of the 911 based racecars, the

Straight Cut Gears

[gettinOld]

👍🏽