I recently added a new sound to my X1c in the form of a very loud POP, as if some sheetmetal is dented and popping back into shape. It is not that but it sounds like it.
every attempt on recording the sound has failed because I cannot reproduce it. It just happens now and then and I cant wrap my head arround on where is comes from, anybody an idea?
To me this sometimes happens if the print head is over the poop chute and afterwards directly goes to the right instead of going forwards first. Then the lever of the chute catches under the print head housing and the plastic of the print head gets yanked pretty violently. I think it mostly happens after the first layer inspection - after I turned that off I rarely encounter it.
Could be a stressed pannel on the right / left. On high temps the tape in the middle could have lost adhesion.
When during the print process does this occur? And does it happen every print, most prints, or just occasionally? Does it usually happen at the same time?
In the mechanical engineering world, this is sometimes called “Oil Canning” for self-evident reasons. 
But I’m going to vote for the poop chute wiping arm (not the wiper for the nozzle). Next time it happens look to the poop chute to see if that lever is moving back and forth, still, from being whacked by the print head.
noticed that too, seems only to happen when the head get’s cleaned after the first layer and then lidar scans it… didn’t get around to yet to see exactly what happens, but it’s worrying me… doesn’t sound “healthy”
It also happens when not printing, there is no exact time or moment when this happens. Sometimes it happens more often or sometimes not at all. Still have to pinpoint where it comes from
This description is the closest to what I think I’m hearing
Same issue here on my new X1C, is it normal ? I feel like it definitely is related to the cleaning in the initial stages of the print.
Can some one record the sound there hearing so we can play it might help to let you k.ow if its a problem or not.
I experience this exact same issue on my X1C, the chute lever seems to be caught inside the rear of the print head housing and when the head moves forward, the lever “snaps” with a pretty alarming pop. It doesn’t seem to cause any damage, but it has caused me to spill my coffee on more than one occasion!
Tolles Thema … this make my day 
+1 - this just started to happen to me as well. I notice it after the first layer goes on, but before the lidar scan.
Was this ever solved? I’m experiencing the print head catching the lever arm too. Was thinking about designing an extension for it
Looks like the latest firmware update fixed this. After wiping to begin scanning the first layer, the print head moves right first then proceeds forward to scan.
If you pay close attention, you will see the print head go first to the right and then to the front. The movement to the right is new.
This is 2024 in May and I just did the latest firmware update. Now I’m getting the loud pop too. MY AMS just failed. I’ve had the X1c for a little over a month. I have ordered a new AMS so we can tear this one apart and find what is wrong. The AMS in the #2 slot keeps saying it can’t retrack the filiment. I did open the AMS up and on a different slot gou out a broken off piece of filament but the #2 slot is still blinking red even when no spool is present. So I disconnected the AMS completely and put filament on the external spool holder. It is working fine. 25 min left on current print job. I know my AMS is under Warrenty but Bambu’s customer support is worthless. It is pretty much, "you bought it, you deal with it’.
They don’t respond to my messages.
I just did the firmware update too and the loud pop is louder than ever. Confirmed that it only happens when the print head moves forward from the chute rather than to the right first; it’s cleaning the print head and then before moving forward it moves back to the position directly above the chute and moves forward and CATHUNK! @BambuLab I think this should be addressed, it’s freaking some users out.
They really should fix this. I don’t own one of their printers yet but seeing posts like this on their own forum that are a year old and totally unresolved and unanswered by support does not make me want to own one.
@AeonJoey They’ve done that since forever, “its a feature not a fault” 
. The “POP” has become quieter over a few firmware upgrades but it’s a noise that is attention getting the first hundred times, these days I don’t hear it and my printer sits beside me.
@user_4059981107 Its unresolved because this particular noise is normal.