07-27-2019, 06:27 AM | #23 |
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The thing that comes up is that manual downshifting into too low a gear may have a bearing (pun not intended) on the whining. If it's not the missing foam noise insulator mentioned before then too much stress is being put on the dct with these sudden change downs. A race car with straight cut gears, which produce a fair amount of whine, can take this abuse but not an M for a prolonged amount of time.With seven gears and reverse the bearings themselves may be smaller than say a 5 speed s/auto in the confines of the casing and I believe it is the shaft bearings crying enough.Worn clutches wouldn't make this noise.
Personally I don't take the settings above Sport and prefer to keep it mostly in full auto where it changes down at the correct time without suddenly skipping to a lower gear. |
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07-31-2019, 12:08 AM | #24 |
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My car sounds the same under load, I suspect it's related to the dct oil pump. If you type "dct transmission oil pump upgrade" in the search bar of Bimmerpost, sspkris talks about an oil pump upgrade and stating that failing bearings will make a whining noise coming from the transmission. Just a thought.
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08-02-2019, 07:50 AM | #25 |
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I have a 6 speed car and have the same noise so I doubt it's the DCT's fault. The noise got slightly more audible after installing a Rogue shifter. I did reinstall all of the insulation but the first bottom piece is tough to remove/install so I broke the plastic part of the seal. I doubt it's totally sealing right now. A replacement is surprisingly cheap, ~$25 so I'm going to order one and see if it helps.
I will listen more closely now that I've seen this thread, but I also think my noise goes away in 5th! |
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03-07-2020, 10:18 PM | #26 | |
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03-08-2020, 07:21 AM | #27 | |
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03-08-2020, 07:57 AM | #28 | |
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After it started making noise I changed diff fluid also and it was already dark after only 3k miles. Guess mine never got the updated differential. |
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11-22-2021, 05:05 AM | #29 |
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Kar001 did you ever get to the bottom of this? Because last weekend I had my car mapped finally (to get rid of the CEL due to catless DP), on the first attempt of measuring power with a road dyno the clutch slipped in 4th (even though XHP was put on the DCT beforehand, it seems it was abused slightly by the previous owner). After that it behaved normally and I went for a "hard ride" on a mountain pass and after 1/4 of the climb it started making this NEW whine like a supercharger. It was never present before in any gear etc. Don't believe it's the motor since it doesn't happen in neutral when revving.. just under hard throttle/acceleration. Video taken as soon as it started occuring:
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11-22-2021, 05:48 AM | #30 | |
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03-21-2022, 09:43 AM | #31 |
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05-06-2022, 10:09 PM | #32 |
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The noise will be quieter or non-existent in 5th gear because that is the 1:1 ratio straight through the gearbox. Every other gear uses a lay shaft and it will be a gear mesh issue or a lay shaft bearing issue.
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05-01-2024, 09:32 PM | #33 |
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