Plz Help, s55 like noise on downshift

[Shadow125]

So randomly two weeks ago on downshifts,DCT, (and after let off throttle on medium-hard pulls) the car is making a f8x like blip noise. I considered it to be a misfire possibly so replaced a suspected troublesome coil & plug for good measure. No good. Retuned the MSS Tune & DCT tune. Can’t get any fault codes out of the car.

Really confused about this as it definitely doesn’t sound happy & I’m sidelining the car until this is fixed. Anyone who may have come across the same issue before please advise. Checked all over various forums and found nothing.

Here’s a link to the best video of the noise I could get, you’ll have to listen closely, in Aus there’s mobile phone cameras everywhere so I had to be very careful. The noise in the video is small & quiet, but in person it’s horrific.

https://youtube.com/shorts/Pqtyv7ZTqTM?feature=share

[RocketyMan]

If you're concerned about misfire, I would use ISTA D and run through the mis-fire panel. It's very helpful and cuts straight to the point for any cylinder suspected of misfire or such.

[Shadow125]

Update -
After using ISTA, nothing was obviously wrong. Since I’ve been on the warpath replacing every damn part known to cause issues. The only things I haven’t replaced now are the entire DCT or the fuel pump.

Really looking for any help here

[RocketyMan]

Originally Posted by Shadow125

Update -
After using ISTA, nothing was obviously wrong. Since I’ve been on the warpath replacing every damn part known to cause issues. The only things I haven’t replaced now are the entire DCT or the fuel pump.

Really looking for any help here

You could also use INPA to look at the shadow memory for any pending fault codes as well.

Did you use ISTA D and look at the misfire panel on a cold engine startup? The panel has a very nice graph feature that is immensely helpful. Otherwise, I'm not to sure what you're trying to describe on your video, or I'm not hearing what you're trying to describe.

I used it here:
https://www.m3post.com/forums/showpo...50&postcount=7

[Redd]

Originally Posted by Shadow125

Here’s a link to the best video of the noise I could get, you’ll have to listen closely, in Aus there’s mobile phone cameras everywhere so I had to be very careful. The noise in the video is small & quiet, but in person it’s horrific.

https://youtube.com/shorts/Pqtyv7ZTqTM?feature=share

Am I the only one who doesn't hear any weird sound? Is the sound before or after the downshift throttle blip?

[RocketyMan]

Originally Posted by Redd

Am I the only one who doesn't hear any weird sound? Is the sound before or after the downshift throttle blip?

I don't hear any weird sound neither...but am trying to offer ways to check/verify with data for the concern.

[spammysammich]

I think he’s complaining about a little afterfire after the blip and downshift? Really seems to be par for the course with aftermarket tunes. Especially if the cats have been deleted. My car does the same thing but I’ve never experienced a stock tune or stock E9X for that matter. Seems normal to me.

[drwankel]

I hear it as well. The aftermarket tune is a wildcard here.

My car usually doesn't make any popping noise, but every once in a while I'll get a very small one after a downshift. My tune is not stock, and does not have any burble tune options added.

I would honestly recommend reloading the stock tune and see if the issue persists. It would help you eliminate the tune as a culprit if nothing else.

[Shadow125]

Well this took off since I last checked.

I've had multiple tunes on the car & stock tune now trying to see if it is tune related.

Still has the damn misfire. I've driven this car for around 70,000km now & I'm very in tune with all the noises it can make. This unfortunately isn't normal. It's a real shame I can't get a decent clip of it, I'll get a buddy to film from outside.

Since I last updated, I've had 3 shops look into it, & went on a very comprehesnsive part replacing journey. Still nothing.

Nothing provoked this, hence why its so confusing.

I'll get a better vid for everyone, I trust there's a hidden wizard with the answer on here

[Shadow125]

Originally Posted by RocketyMan

You could also use INPA to look at the shadow memory for any pending fault codes as well.

Did you use ISTA D and look at the misfire panel on a cold engine startup? The panel has a very nice graph feature that is immensely helpful. Otherwise, I'm not to sure what you're trying to describe on your video, or I'm not hearing what you're trying to describe.

I used it here:
https://www.m3post.com/forums/showpo...50&postcount=7

Damn when I attempted to use the misfire panel I had nothing like this, just a small live readout in a list for each cyl. Maybe finding this will help. Any clues as to where it's found ? I searched pretty deep through ISTA (or so I thought)

[RocketyMan]

Originally Posted by Shadow125

Damn when I attempted to use the misfire panel I had nothing like this, just a small live readout in a list for each cyl. Maybe finding this will help. Any clues as to where it's found ? I searched pretty deep through ISTA (or so I thought)

The misfire panel is on ISTA. I'm not sure what you're looking nor describing exactly. Maybe try "scrolling down" as it may not be intuitive. Maybe post a screenshot.