[BunkerJ]

Originally Posted by rjdnyy224

That's what I would've guessed as well, but I would have figured BMW would've designed the chain and it's path to make as little contact with the guides as possible, for longevity purposes.

Well, that's the point of the guide... Haha. It's there to guide the chain and provide the path, while the tensioner helps to remove slack. The issue isn't that it's supposed to last for 200k+ miles, but it going prematurely under 70k is pretty bad. If the car has been turned off for awhile (which it should be since you're going to touch the chain), the oil should be mostly gone from the tensioner and thus giving slack. The noise is pretty loud and best assessed without the belts as well. At least for me, the turbo noise would likely mask it while driving, so no load is also the best way to assess it. While some do just go without any warning, most will give that "dying cat" noise. The best thing you can do right now is to continue to check and ensure AS/S is turned off manually or coded out, as it rapidly accelerates this issue.

[Hammer Werke]

Wouldn't scoring just be caused by the chain running over metal gears/cogs?
Just like a bike chain.

[rjd_F30]

Originally Posted by BunkerJ

Well, that's the point of the guide... Haha. It's there to guide the chain and provide the path, while the tensioner helps to remove slack. The issue isn't that it's supposed to last for 200k+ miles, but it going prematurely under 70k is pretty bad. If the car has been turned off for awhile (which it should be since you're going to touch the chain), the oil should be mostly gone from the tensioner and thus giving slack. The noise is pretty loud and best assessed without the belts as well. At least for me, the turbo noise would likely mask it while driving, so no load is also the best way to assess it. While some do just go without any warning, most will give that "dying cat" noise. The best thing you can do right now is to continue to check and ensure AS/S is turned off manually or coded out, as it rapidly accelerates this issue.

Fair enough lol. I guess it just doesn't seem like the best idea to have the chain constantly rubbing up on the guides, but I guess that's the only way to guide the chain haha.

Upon further review, like I said before I'm definitely not experiencing the dying cat noise. From here on out I'll do a thorough check for noise every 1k miles or so, hood open, out in front, having a friend or whatever rev for me. I've never used AS/S ever since I've owned the car (forgot to turn off here and there, rarely, but YKWIM). Hopefully previous owner didn't either.

[BunkerJ]

Originally Posted by rjdnyy224

Fair enough lol. I guess it just doesn't seem like the best idea to have the chain constantly rubbing up on the guides, but I guess that's the only way to guide the chain haha.

Upon further review, like I said before I'm definitely not experiencing the dying cat noise. From here on out I'll do a thorough check for noise every 1k miles or so, hood open, out in front, having a friend or whatever rev for me. I've never used AS/S ever since I've owned the car (forgot to turn off here and there, rarely, but YKWIM). Hopefully previous owner didn't either.

I got mine at 55k and was likely owned by just a casual driver who used it. Ever since owning it, I've had it coded out with no issues thus far.

[rjd_F30]

Originally Posted by BunkerJ

I got mine at 55k and was likely owned by just a casual driver who used it. Ever since owning it, I've had it coded out with no issues thus far.

Same here, got mine at 46k. Likely was used before, just judging by typical 328i buyer demographics. Didn't code it out but turn it off everytime I step in the car. My mom's E84 X1's AS/S stayed off even after leaving the car, only had to turn it off on delivery day and never worried about it since. I wish

[BunkerJ]

Originally Posted by rjdnyy224

Same here, got mine at 46k. Likely was used before, just judging by typical 328i buyer demographics. Didn't code it out but turn it off everytime I step in the car. My mom's E84 X1's AS/S stayed off even after leaving the car, only had to turn it off on delivery day and never worried about it since. I wish

Videos are (slowly) going up. I'll edit with links in probably 15 min.

Edit: Audio:

Visual/Physical Inspection:

[lonecitizenfour]

your car sounds fine to me. the cars with issues sound like they have a supercharger on them...

[BunkerJ]

Originally Posted by lonecitizenfour

your car sounds fine to me. the cars with issues sound like they have a supercharger on them...

Exactly. Dying cat is the term I like to use lol.

His car is good ATM.

[rjd_F30]

Thanks for all the input guys and for calming my timing chain paranoia lol. BunkerJ thanks for the vids

[DBU]

Well, I am going to disagree with the majority here. The scoring marks on his TC are indisputable and of concern. As to whether or not we can hear the whine (dying cat is a good analogy) probably depends more on the cell phone(?) microphone being able to pick it up or not. But the marks are there and OP is close to 70K, so absolutely no doubt he should go to the dealer ASAP. If for no other reason to document his concern BEFORE 70K in case the motor goes bad at, say 75K and he then is looking for BMW goodwill.

On one occasion, I have observed the seemingly excessive slack on my cold (N20) engine. At several other checks, the slack has been minimal.

[rjd_F30]

Originally Posted by DBU

Well, I am going to disagree with the majority here. The scoring marks on his TC are indisputable and of concern. As to whether or not we can hear the whine (dying cat is a good analogy) probably depends more on the cell phone(?) microphone being able to pick it up or not. But the marks are there and OP is close to 70K, so absolutely no doubt he should go to the dealer ASAP. If for no other reason to document his concern BEFORE 70K in case the motor goes bad at, say 75K and he then is looking for BMW goodwill.

On one occasion, I have observed the seemingly excessive slack on my cold (N20) engine. At several other checks, the slack has been minimal.

Interesting. Wouldn't the scoring just be from the chain rubbing up on the guides like everyone said? Can you all post pics of your chain so I can see if you have the same marks?

Regarding the noise, I can assure you I don't have the dying cat. The noise I was hearing is the natural whine/whirr of the engine, but I was paranoid and misinterpreted it. After further listening and analysis, I am 100% sure I don't have the dying cat noise.

EDIT: this thread: https://f30.bimmerpost.com/forums/sh....php?t=1333666 also shows that almost all N20 owners (in that sample) had scoring on their chain as well.

[BunkerJ]

Originally Posted by rjdnyy224

Interesting. Wouldn't the scoring just be from the chain rubbing up on the guides like everyone said? Can you all post pics of your chain so I can see if you have the same marks?

Regarding the noise, I can assure you I don't have the dying cat. The noise I was hearing is the natural whine/whirr of the engine, but I was paranoid and misinterpreted it. After further listening and analysis, I am 100% sure I don't have the dying cat noise.

EDIT: this thread: https://f30.bimmerpost.com/forums/sh....php?t=1333666 also shows that almost all N20 owners (in that sample) had scoring on their chain as well.

That and the gears. Scoring has been normal for this engine. I mean, I'm at 90k and have had scoring since I bought the car 40k miles ago. Trust me when I say you'd know if you were one of the lucky ones that got the noise. It could be an old Razer phone and it'd pick up that screeching thing lol.

[DBU]

Originally Posted by rjdnyy224

EDIT: this thread: https://f30.bimmerpost.com/forums/sh....php?t=1333666 also shows that almost all N20 owners (in that sample) had scoring on their chain as well.

Old thread - probably from before we knew what those scorings really mean.
My N20 motor with about 18k miles on it has zero scoring marks.

[rak299]

I am not an expert on that engine or its timing chain problem, but the side-to-side movement is normal and necessary if the chain is to move over the sprockets. A loose timing chain has movement in the other direction. (the way the tensioner pushes).

[BunkerJ]

Originally Posted by DBU

Old thread - probably from before we knew what those scorings really mean.
My N20 motor with about 18k miles on it has zero scoring marks.

Because 18k miles...

[rjd_F30]

Originally Posted by BunkerJ

Because 18k miles...

+1 I'd hope you don't have scoring at 18k miles. That thread isn't that old. If we discount 1 year old threads as non-reputable, than we slice our wealth of knowledge on the forums into a fraction of what it really is.

[BunkerJ]

Originally Posted by rjdnyy224

+1 I'd hope you don't have scoring at 18k miles. That thread isn't that old. If we discount 1 year old threads as non-reputable, than we slice our wealth of knowledge on the forums into a fraction of what it really is.

Seems scoring starts to appear around 40-50k on most. I'm not saying it's great but it doesn't appear severe on most engines.

[F30ed]

1. 'Scoring' cause by traveling over the guides is normal, made by contact of 2 surfaces.
2. 'Scoring' cause by traveling over the guides can not be seen from the oil fill hole - it is on the inner edge of the chain (bottom if you look top down thru the hole)
3. Scoring on outer edge (the one you see thru the hole) is cause by 1 thing only (if I remember correctly) - tensionner boot. All it indicates that the tensioner works. If too much "scoring" - may indicate the chain is stretched.

[sspade]

Im going to inspect my chain for slack and scoring this morning... will report back.

Im at almost 57k miles.

[loggin]

Originally Posted by F30ed

1. 'Scoring' cause by traveling over the guides is normal, made by contact of 2 surfaces.
2. 'Scoring' cause by traveling over the guides can not be seen from the oil fill hole - it is on the inner edge of the chain (bottom if you look top down thru the hole)
3. Scoring on outer edge (the one you see thru the hole) is cause by 1 thing only (if I remember correctly) - tensionner boot. All it indicates that the tensioner works. If too much "scoring" - may indicate the chain is stretched.

I believe we do see the side of the chain that makes contact with the guides through the oil filler hole.. I will try to attach a photo and you can decide for yourselves..

[sspade]

My chain is as tight as can be and has ZERO play when ice cold as well as when hot. No visible scoring. 57k miles.

One thing I did notice was white smoke coming out of the opening when I went to check the chain after driving. Never done this before so not sure if that's normal or not?

[BunkerJ]

Originally Posted by sspade

My chain is as tight as can be and has ZERO play when ice cold as well as when hot. No visible scoring. 57k miles.

One thing I did notice was white smoke coming out of the opening when I went to check the chain after driving. Never done this before so not sure if that's normal or not?

Normal. That's just the oil. And are you sure? Maybe it's just the photo but looks like some on the center of the links.