Wastegate rattling noise between 1500 - 1700 rpm

[1000hp]

Holy shit. Is that what you guys are hearing?

[f80bm3]

Originally Posted by DrewDDS

Did you notice any soot buildup around the connection?

It's tough to say because I changed out the midpipe shortly after I got it back from the dealer but i do remember hearing that it was a little loose if sorta hit the midpipe around that connection

[papasmurf_m3]

Jeezus that sounded like a chop saw cutting through metal.

I get the tiny little buzzing kinda noise it's not super loud. You have to really pay attention. Nothing like that video.

1500 rpm under partial throttle. No codes no issues, logs are perfect.

No idea, maybe its the WG arm, or that rod. You an literally jingle that thing by hand so who knows if its vibration from the downpipes that cause that to jingle.

But, its nothing big and I forgot about till i saw this post.

[billypopo]

This thing is driving me crazy. Bmw replaced the crush washer between the mid-pipe and the down-pipes as someone here mentionned it fixed his issue, but it didn't fix it on mine. They did it under 'good will' as they say they don't hear anything…

I'm thinking of changing the exhaust just to fix this, but i'm unsure about which part I should focus on first; dp, midpipe or the muffler/cow belly?

With DP i'm concerned about having a cel, any good option out there to avoid it?

Any input is more than welcome.

[schlichtm3]

In the meantime, I have exchanged the original muffler for one from AC Schnitzer with new flaps, of course.

The rattling is still there, as described, because it also clearly comes from the front right.
I assume that it is the Wastgate flaps.

[papasmurf_m3]

That is not wastegate that's exhaust vibration. Probably world gaskets and metal to metal harmonic briefly you are hearing.

[billypopo]

Originally Posted by papasmurf_m3

That is not wastegate that's exhaust vibration. Probably world gaskets and metal to metal harmonic briefly you are hearing.

I tend to agree with you. Were you able to get rid of it? I see you had it also with MPE, so what's your best guess, is it the mid-pipe or the down pipes causing this?

[papasmurf_m3]

Originally Posted by billypopo

I tend to agree with you. Were you able to get rid of it? I see you had it also with MPE, so what's your best guess, is it the mid-pipe or the down pipes causing this?

Yes it's likely just some exhaust jingling at a certain rpm.

Doubt it's anything we need to worry about.

I push the car through it's paces and all is well.

[fanofbmwe46]

There are multiple rattles that folks have experienced and that are talked about in this thread. There definitely is a wastegate rattle slightly different from the last video posted in this thread. It drove me nuts for months… I actually ended up trading in the car because of it and because my AC evap and condenser were leaking.

[blumagic]

I’ve probably put 10 hours into the waste gate arms with no success

Car has to be warm, somewhere in the 1500 rpm range with load

The n20 actuator clip fits perfect (reversed) to remove slop - that did nothing

I was able to use a spring to get tension on the rear turbo (like the n54 fix) to see if it was the slop from the part that goes to the turbo housing - that did nothing, although I could not find a spot for the front, there was no change in sound, frequency, or anything at all

I was also able to get an e clip between the rear pin and arm, that did nothing.

Im starting to think it might be the down pipe to mid pipe connection or the flaps. Idk… out side of the car it sounds like it is underneath or at the rear… inside sounds like it is at the front

View post on imgur.com

[blumagic]

I think I may have found it, something is going on with the mid pipe and it doesn’t seem to come from the down pipe connection.

It would kind of make sense why someone who changed the mid pipe, fixed the noise. Where another who just changed the gasket stayed the same.

Here im just bumping the mid pipe with my hand… it’s the pipe itself making all that noise

View post on imgur.com

[Dotframe]

I get the exact same thing on my new to me '18 F82 ZCP. Car has around 20k miles and is bone stock. Rattle at 1500-1700 RPM under load. I pulled the plug on the exhaust valves while they were fully open but that had no effect. Will be climbing under the car this weekend to start the journey of identifying where mine is coming from.

[Shubacca]

Originally Posted by blumagic

I think I may have found it, something is going on with the mid pipe and it doesn’t seem to come from the down pipe connection.

It would kind of make sense why someone who changed the mid pipe, fixed the noise. Where another who just changed the gasket stayed the same.

Here im just bumping the mid pipe with my hand… it’s the pipe itself making all that noise



https://imgur.com/a/NRaD5F8

This has to be it, that sound you were able to make is very familiar. Heat shield? Exhaust hangar?

[Dotframe]

So I got under the car while it was cool and could barely hear a tinny rattle when hitting the downpipe/midpipe connection with a rubber mallet.

Then drove around until the car was good and hot and it was making the rattle sound as usual (only under load 1500-1700 RPM). Got home and hit the downpipe/midpipe connection again with the rubber mallet and sure enough it was rattling more.

I can't say yet if this is 100% of the problem, but definitely a similar sound. I think someone mentioned replacing the gasket there at that connection. I'm going to get new bolts and a new gasket and give it a shot.

Also, I am not getting much rattle at that same bracket as blumagic. I guess there isn't one solution...

[blumagic]

Originally Posted by Shubacca

This has to be it, that sound you were able to make is very familiar. Heat shield? Exhaust hangar?

I tried a couple things

Took off that bracket before the secondaries, noticeable wear from heat/vibration

View post on imgur.com

Tried driving with it off - no change

Put it back on but tried to slide it closer to where I heard the noise. Now it seems a little quieter and less frequent when reversing up my drive

I did this because when I put pressure on the pipes near the welded bracket the clanging/rattling was reduced when I tapped on the pipe

The noise sounds like it is inside the mid pipe, the one closer to the passenger side where the welded bracket is

It rained the other day and ambient temps were cooler, it was noticeably more quiet.

Makes me think the exhaust flow change when the waste gate is closed/closing mixed with heat expansion is causing this noise within the mid pipe at this specific rpm.


If the internal WG was rattling I would think it would be on throttle lift and would get worse up the rev range


I think I’m just going to go for a new mid pipe, I have all the hardware for the down pipe connection but the sound seems further down so I’d rather not waste the crush gaskets since I want a little more (good) noise anyway

[Shubacca]

That's interesting because I have, what I assume, is the same rattle as you based on your description and have an AA single mid pipe and otherwise stock exhaust system. The mid pipe went on so quickly after I bought the car that I never noticed whether the rattle was there before or not.

I also have been unable to replicate the sound when the car is in neutral. I hear the rattle only when in gear and under any load as RPM increases through ~1600-1800. I guess maybe I should put it on a lift and grab a hammer to see if my sounds emanates from a different location.

[billypopo]

Originally Posted by Dotframe

So I got under the car while it was cool and could barely hear a tinny rattle when hitting the downpipe/midpipe connection with a rubber mallet.

Then drove around until the car was good and hot and it was making the rattle sound as usual (only under load 1500-1700 RPM). Got home and hit the downpipe/midpipe connection again with the rubber mallet and sure enough it was rattling more.

I can't say yet if this is 100% of the problem, but definitely a similar sound. I think someone mentioned replacing the gasket there at that connection. I'm going to get new bolts and a new gasket and give it a shot.

Also, I am not getting much rattle at that same bracket as blumagic. I guess there isn't one solution...

I tried changing the downpipe/midpipe connection (dealer did) on mine and it didn't change anything

[Shubacca]

Everything is solid and silent on mine from the DP/Mid pipe connection back. I tapped every inch with a rubber mallet including the exhaust valves. I was able to create a tin-metallic rattle when I hit the DP/mid pipe connection and think I isolated the rattle to the gold heat shields on the stock down pipes. Either that or something inside the lower 1/2 of the DP. I pried on the left (inboard) down pipe heat shield a little, which did nothing to alleviate or worsen the sound. However, when I drove the car after, the rattle was much harder to produce and was a lot shorter in duration - hard to actually notice.

The rattle I created with the mallet either came from the accordion portion of the lower DP or the heat shield. I think it was either mostly or entirely from the left (circled) shield.

I think I may try and remove the OEM shielding and use a conventional heat wrap. I don't want to replace DPs because I'm pretty happy with my car's sound and have heard you get into a lot of rasp and other bs that I'm not trying to deal with. Could just be my ignorance talking since I ruled DPs out a while ago.

[blumagic]

Mine could be coming from that area too, went under again today and my rattles just reverberate through the pipes and make it difficult to pinpoint

Same rattle happens if I hit a down pipe with my hand. Maybe mine is crush gaskets? Idk I’ll keep chasing it and updating

[Stollywood]

Be interested to know if this sorts the problem. I am
having the same issue. Bought the car about 6-7 weeks ago and never noticed anything. Since the hotter weather has arrived and driving with the windows down this rattle has appeared and is doing my head in. Sounds like stones in baked bean can. Car is in with dealer next week but you can never guarantee they will do anything.

[blumagic]

Got it to rattle in neutral, put my head under the car and used the throttle by hand. It’s about 8-900 rpm and quieter but it’s there

Now it sounds like the damn secondary cats lol

I’m throwing a party when I get this figured out

View post on imgur.com

[Rokoz]

Thought this video might be of interest to some of this thread