'11 r60 sall4 117k mi, larger intercooler, deleted noise generators on intake, replaced with Borg Warner JCW model number turbo, ECU "stage 2" remap to 22psi bost (via Mario)


There's a few things going on here that I'll add in for context, but the issue I'm most concerned about is a LOUD knocking type sound that I do not believe is related to those other issues.

To get ahead of regular questions-
-I have been scouring the internet, watching youtube videos, and I looked at probably half a dozen posts here at NAM around the subject already
-no codes/check engine thrown, yes I have a foxwell scanner that reads/resets bmw/mini specific codes and does things like registers the battery/etc
-no smoke
-no smells
-no weird sounds prior
-shadetree style home mechanic here that has been messing with cars for the last 25 years


All dates approximate
3/1/2021 We'll start here. The only major/known issues I was having with Mistress was her clutch that was slipping, and what sounded like the starter motor getting ready to go out (or a bad bearing in it?). I also replaced her lower engine mount, and put 1 side in of the poly bushing insert because I couldn't get the dad gum thing in with both sides in! I knew my engine was moving a bit, and figured I'd knock that one out real quick.

3/9/2021 I had my clutch replaced at a -very- reputable local independent shop called Ferney's (which has the backing of the local Mini owners group, the mechanic owner used to work at the Mini dealer here) with a clutchmasters fx400 with aluminum single mass flywheel. I went easy on her for the first 500 mi as directed. I've read stories about clutch chatter, and I did have some of that. It's not any louder than the ambient engine noise, but you can def tell the clutch makes some "static" noise at idle. From the time I got her back she would "buck" when starting in first, but was fine in any other gear. The bucking got worse and worse, and I attributed it to me changing that lower mount, but not the upper two, thinking the lower was now not moving, but the uppers were allowing movement, which would "feather" the clutch in/out slightly, causing the buck. No issues with feeling anything "binding" when turning (I had already replaced the whole rear carrier, clutch pack & diff, so I know what that feels like), so I don't believe there was any issues with at least the rear drivetrain.

4/6/2021 Out of nowhere, the bucking decreased -significantly- on those 1st gear starts. But I did notice something -extremely- odd.....One day I could power through a corner, and the next day I have torque steer for the first time since acquiring the vehicle a year ago. I no longer had all4! No weird sounds/smells/vibrations/etc. I was without a doubt only getting power to the front, as I could now easily spin the front tires when taking off from 1st! I'd never done that before, or even spun all 4 tires outside of it being wet/snowy. With the car in gear and turned off, I can (barely) spin the rear drive shaft by hand, not that doing that specifically means anything, I'm sure the clutch pack between the transfer case/power take off and rear diff is not normally engaged when the engine is off, and/or the xfer case probably goes into some "neutral" equiv when the car is off.

4/29/2021 I start getting a very-very occasional LOUD knock sound. I thought maybe it could be an exhaust manifold gasket leak (since I was impatient and didn't change it when I replaced my turbo and mani about a year ago), or maybe the heatshield banging against something. I also had a feeling that maybe it could be the death rattle of the timing chain. I popped the valve cover and did find the exhaust side guide was missing a decent chunk out of the upper part, where it slightly curves inwards towards the cam gear. So, I thought this may be the culprit so I stopped driving her and I ordered a bunch of parts to replace that and a bunch of other things while I was at it (oil pan wasn't drip -leaking-, but was "wet" at the seams so I did the gasket; also found when I did the turbo I misrouted/crossed the oil line over the coolant return line, so they were touching and the oil line was burning through the coolant line; upper motor mounts; exhaust gaskets, etc.).

6/8/2021 Finally got everything changed out and got her put back together. It took awhile because of vacations, and parenting time. Mistress isn't my only vehicle, so it's not like I HAD to get her back up and running asap. She started -right- up on the first try, like she had not just undergone a bunch of repairs. But the LOUD knock was even worse now. When I drained the oil for the work, I did not see any metal bits anywhere (and I have a mag drain plug, no noticeable chunks, just a few very very fine shavings, like you'd see if you took a magnet to iron rich dirt, and what I would expect to and do see out of other cars. When I dropped the oil pan, I again didn't see any metal bits at all in the pan. And if you recall the drain is actually raised like 1/2in above the bottom of the pan, so you're always leaving a little bit in there without putting a vacuum line in there to suck up the rest. So if there were any shavings/bits, I would have for sure seen them. As for the timing chain guide piece, I never found it. But I know the oil pan has been dropped before (3 holes were already stripped. bleh), so a previous owner/shop could have already gotten that piece out. I did find the other small dime sized piece that was missing from the timing guide, and it matched up perfectly so I don't have any concerns that it disintegrated and put bits everywhere.

6/9/2021 I take the valve cover back off and take some time to go over each area, thinking that the "larger" plastic timing chain bit is bouncing around, but find nothing at all.

6/10/2021 Here I am, posting all this.


To recap, these are things I have cursorily ruled out-
-not the "regular" farm truck/sewing machine sound these direct injected n18's make. see videos below
-I don't feel like it's a spun bearing/rod knock, because I would expect it to have a chirp to it at some point (and there's been none), be -constant- with the engine running, not random as it is now, be -significantly- louder from under the car coming through the oil pan since it would be hitting in that area
-not belt tensioner pully/water pump wheel/dogbone-friction pulley. It seems like it's coming from the valve train, towards the driver side towards the back of the engine bay, almost like something is making contact with the plastic valve/pcv cover.....but when I removed it that second time I didn't see any areas that looked like something was hitting it. That said, I have not done a "screwdriver" or stetho test to really isolate where the sound is coming from yet.
-not clutch chatter. This is WAY louder and different than the chatter I noticed when I picked her up after getting the new clutch
-not timing chain/guides/tensioner, since these were just replaced
-I really don't believe it to be a timing issue, unless the crankshaft sprocket slipped somehow. I was able to get the flywheel locking tool in there, after rotating the engine a few times, and both cams had the labels facing straight up when I then put the cam locker tool on. So if all those lined up, I just don't see it being timing. That said, I did not measure to make sure I was TDC on any pistons, so, sure, there's a 1% chance this is the issue.
-I gave all the bolts under the valve cover a "hand tighten" to see if any were loose at all, and none seemed like they were loose when applying a very decent amount of pressure.
-It's not at least the upper heatshield, because putting a bar on it and pushing pretty hard doesn't change the sound one bit, and it doesn't sound like a heat shield rattling to me




And now for the real show, videos for sound comparison! Lets see if these link properly.


1. Here's one that was taken when my all4 went "missing". This is what I expect her to sound like, the farm truck/sewing machine sound, so this is the "base/normal" sound to compare the others to.

2. This one was 2nd start after I had finished putting her all back together. I hit my hand on the valve cover because that's where it seems like the sound is coming from. It definitely sounds like it's on top, and towards the drivers side for sure, not from the passenger side where the timing chain/belts/pulleys are. Kinda harder to hear in this video, but it also seems to -significantly- go away with a little throttle

3. in and out on the clutch from inside the cabin. note the difference in the sound and frequency it happens

4. a couple seconds in on clutch, a couple seconds out from under the car



I have a borescope on order that arrives on Sat so I can try inspecting some areas. And unless by some miracle i figure it out before hand, I'll be taking her back to Ferney's to see if they can figure it out. But if anyone else has seen/heard this type of sound, I'd appreciate any pointers!


(ps. dang good thing I saved all this typing before hitting preview....it made me re-login and everything was -gone-!)

 

Based on the noises changing with the clutch going in and out, I’d be thinking driveline related, but it’s really hard to tell spatial relationships over the internets

 

Yeah, that's why I put up a "before" video, so at least there'd be a base reference for the sounds I expect to hear versus this new one. And I'm also somewhat hoping it's more clutch related....and applying the logic I always use from my IT Career: "whatever the last thing to change is 99% of the time the cause of the new issue". Mainly I won't be too upset as long as it's not a spun bearing!

But if it is a spun bearing, I do have a (non-mini) ext warranty that I've already gotten my money out of, so this will be icing on the cake if they cover the named rod bearings that are listed in their definitions