F30POST
F30POST
2012-2015 BMW 3-Series and 4-Series Forum
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
BMW 3-Series and 4-Series Forum (F30 / F32) | F30POST > Technical Forums > N20, N26, B46, B48 Turbo Engine / Drivetrain / Exhaust Modifications > Clearing Up Timing Chain Inconsistencies
European Auto Source (EAS)
Post Reply
 
Thread Tools Search this Thread
      10-31-2018, 02:31 PM   #67
rjdnyy224
Brigadier General
rjdnyy224's Avatar
United_States
1548
Rep
3,205
Posts

Drives: 2013 328i xDrive
Join Date: Jun 2017
Location: New Jersey

iTrader: (0)

Quote:
Originally Posted by qualicas View Post
Got the valve cover off. Special thanks to BMW for putting the Vacuum pump at the back of the valve cover. Spent a long time finding the 3 bolts then getting an Allen key on them! Not looking forward to re-installing it as it has to line up with the cam shaft as well.
Things do not look great. The entire intake side retainer is gone and that is what was in last picture. Also you will note that the vanos alignment holes on the intake look out be a lot. It is looking like something got under the intake sprocket and the chain jumped a bunch of teeth. By the looks of it the intake cam is vastly retarded.
I have been thinking that should not bend valves? Maybe someone else can either confirm or explain if it would bend valves like this. Of course, I have not pinned the crank at TDC yet. I am assuming that the exhaust cam is correct. That could be out if the crank sprocket skipped teeth. Tonight I will check.
In any event, I did look with my borescope and I could not see any piston damage, they all looked evenly Black.
Once I pin the crank and see if the exhaust is correct, I will do a leak down test and see what is what.
The second picture looks like the vanos sprocket teeth are ground down! Surprising then I did not get any metal in oil pan.
Really informative post

Just so I'm clear: what caused all this is the timing chain guides, those broken orange pieces in your first post, just broke, right? Why exactly did they break? Because the chain skipped?
__________________
2013 328i xDrive N20 8AT | Bootmod3 Stage 2 OTS 93oct | Bootmod3 8AT TCU flash | VRSF Street 5" HD Front-Mount Intercooler | VRSF Catless Downpipe | 2.5" custom exhaust cutout | M Performance Exhaust | NGK L/I Spark Plugs | Dinan 20" Wheels Wearing Michelin PS4S's | Dinan Springs and Bumpstops | F80 Style Decklid Spoiler | Debadged | F80 Style Grille | Various Interior Bits |
Appreciate 0
      10-31-2018, 03:08 PM   #68
qualicas
New Member
33
Rep
18
Posts

Drives: 2010 135
Join Date: Jul 2015
Location: Calgary Alberta

iTrader: (0)

This might be a chicken and egg problem. Which happened first? Going to try to figure it out. If chain stretched first I would think it should have slipped over the exhaust teeth? The intake sprocket is a direct pull from the crank sprocket. On the other hand, the intake is only wrapped 90 degrees whereas the exhaust is something more. The chain jumping over the teeth would certainly make the chain hit the retainer and take it out. The pull on the exhaust would be constant since the lobes do not change. Maybe the valvtronic on the intake could vary the load quickly if one floors the throttle so the lobes/valve lift goes from almost nothing to full lift, if the chain is already stretched that might be enough to cause it to slip. Now that I am writing it would seem to me to be a good explanation. If the intake retainer just randomly broke it should have fallen outside of the chain and I believe that is what happened but there would be no way for a plastic bit to jump up and get under the intake sprocket.
Yeah, more I think about it, I would say my first explanation is probably correct.
So maybe do not floor the throttle if the chain is already stretched!
Actually, my chain seems nice and tight still.
If I find any other issues I will report back.
Appreciate 2
rjdnyy2241548.00
Stubok458.00

      10-31-2018, 05:10 PM   #69
BunkerJ
Colonel
BunkerJ's Avatar
1007
Rep
2,382
Posts

Drives: 2013 328i
Join Date: Mar 2017
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by rjdnyy224 View Post
Really informative post

Just so I'm clear: what caused all this is the timing chain guides, those broken orange pieces in your first post, just broke, right? Why exactly did they break? Because the chain skipped?
BMW has described the issue as a faulty polycarbonate that the guide was made of. This could have been two things from what I've seen: Either the guide couldn't withstand the heat and caused the chain to skip OR the lack of lubrication on the constant startup from Auto Stop/Start caused it to wear down much quicker, causing it eventually to skip and shatter the guide. The orange pieces are the guides and are like that because that chain went haywire and bashed them to bits.

It's definitely a low % chance of failure based on numbers of failures but I think the unpredictability is what causes it to be so worrisome. Even when we look at detecting it before failure, it's practically 50/50. Some have noticed that loud whine and some have noticed no changes. That may have to do with how/where it wears down. If it's a more consistent wear, maybe you get that loud whine as a result but if it's more anomalous, you just get unlucky when that small area causes the chain to go haywire.

It also mostly seems to be that those with unmodified (and possibly modified, who knows) may not have something to worry about as BMW seems to be mostly cooperative with people. That seems to vary from fronting a large part of the bill to fronting the whole thing. I think the more occurrences we have, the easier it may get for future failures.
__________________

2013 F30 328i: MHI Big Turbo, GFB DV+, Mishimoto CAI, ER TIC/CP/Catless DP, AWE Touring Quad Exhaust w/ Resonated Midpipe, NGK LI Plugs, BM3 with PTF Stage 2 91 AGG Tune, Fuel-it Stage 2 LPFP, Solowerks S1 Coilovers, and DEPO/M-Sport Retrofit
Appreciate 1
rjdnyy2241548.00

      10-31-2018, 07:48 PM   #70
meltbox
Private First Class
23
Rep
124
Posts

Drives: 2014 328xi GT (F34/N20)
Join Date: Sep 2018
Location: Michigan

iTrader: (0)

That is also an interesting question. If you flash the car or similar and the timing chain clearly failed wouldn't BMW still have to replace the engine...? It seems like it would be hard to argue that a flash put extra strain on a timing chain. This is all assuming you are within warranty/ELW.
Appreciate 0
      10-31-2018, 11:32 PM   #71
qualicas
New Member
33
Rep
18
Posts

Drives: 2010 135
Join Date: Jul 2015
Location: Calgary Alberta

iTrader: (0)

If BMW used polycarbonate for the chain tensioners, no wonder they break. I own an injection molding business. I would NEVER use Polycarb for an interior engine part. Polycarb is good for impact but bad with chemicals. I would start with nylon 66 at a min and work up from there. Now I am going to check my broken pieces, if it is Polycarb, clearly their engineers did not know their business. As well, if someone came to me to mold those parts in Polycarb, I would not do it. As well, now I will examine the design for sharp inside corners and just bad overall design. You would be surprised what a tiny increase in internal radius can do for strength.
We had company tonight so I did not get to have a look at the car tonight.
Appreciate 0
      11-01-2018, 08:04 AM   #72
rjdnyy224
Brigadier General
rjdnyy224's Avatar
United_States
1548
Rep
3,205
Posts

Drives: 2013 328i xDrive
Join Date: Jun 2017
Location: New Jersey

iTrader: (0)

Quote:
Originally Posted by meltbox View Post
That is also an interesting question. If you flash the car or similar and the timing chain clearly failed wouldn't BMW still have to replace the engine...? It seems like it would be hard to argue that a flash put extra strain on a timing chain. This is all assuming you are within warranty/ELW.
It would be a hard argument, a bad argument even, but I can say with confidence that BMW would make it. I'm sure if someone with a tuned N20 still under warranty tried to make a warranty claim on a busted timing chain and thus a (probably) dead motor, BMW would try not to cover it because of the tune. Maybe some cool SA's out there would work with you, but by and large, you'd be screwed.
__________________
2013 328i xDrive N20 8AT | Bootmod3 Stage 2 OTS 93oct | Bootmod3 8AT TCU flash | VRSF Street 5" HD Front-Mount Intercooler | VRSF Catless Downpipe | 2.5" custom exhaust cutout | M Performance Exhaust | NGK L/I Spark Plugs | Dinan 20" Wheels Wearing Michelin PS4S's | Dinan Springs and Bumpstops | F80 Style Decklid Spoiler | Debadged | F80 Style Grille | Various Interior Bits |
Appreciate 0
      11-01-2018, 09:41 AM   #73
kobluna
Private First Class
23
Rep
127
Posts

Drives: 320i
Join Date: Jun 2016
Location: Finland

iTrader: (0)

One more theory for failing timing chain and guides could be that because chain can be very loose when engine is stopped, the chain will put more stress on the guides when engine starts to move again. So everytime that engine is stopped there is a chance that chain is loose (I don't have exact reason why it's sometimes loose and sometimes tight when engine is not running) and then it will rattle more against the guides. When this is repated enough the guides will broke and chain will skip a teeth. If chain is also little bit stretched it will be even harder to the guides.

So I would not use auto start-stop as it increases the strain to the chain. TBH, I don't use it for various reasons, it causes delay when I want to move again, it puts stress to the battery, start motor and bearings.

For the whining, what I've understood it comes from the oil pump chain. (Stretched) Timing chain makes more like a rattling sound which can be heard best when starting the engine. I actually do exhibit some weird metallic rattle when starting up the engine and also on certain rpm range. I will ask the dealer to measure my chain when I have next appointment there.
Appreciate 1
BunkerJ1006.50

      11-01-2018, 09:47 AM   #74
BunkerJ
Colonel
BunkerJ's Avatar
1007
Rep
2,382
Posts

Drives: 2013 328i
Join Date: Mar 2017
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by qualicas View Post
If BMW used polycarbonate for the chain tensioners, no wonder they break. I own an injection molding business. I would NEVER use Polycarb for an interior engine part. Polycarb is good for impact but bad with chemicals. I would start with nylon 66 at a min and work up from there. Now I am going to check my broken pieces, if it is Polycarb, clearly their engineers did not know their business. As well, if someone came to me to mold those parts in Polycarb, I would not do it. As well, now I will examine the design for sharp inside corners and just bad overall design. You would be surprised what a tiny increase in internal radius can do for strength.
We had company tonight so I did not get to have a look at the car tonight.
Here is where I read it from: https://www.carcomplaints.com/news/2...g-chains.shtml

"The lawsuit alleges the plastic guide for the timing chain is made with a defective polycarbonate composition that causes the guide to break apart and lodge in the crankshaft drive sprocket, causing the chain to damage the engine."

I remember reading the lawsuit and it goes through this pretty well. This coincides with them changing the composition of the guide following 2014.

As for the warranty claim, I think it'd be a more difficult battle but I think you'd have a chance still. BMW has often fronted the bill either partially or in full for even those outside of warranty. Now, don't get your hopes up thinking they will even do that but know that others have succeeded in circumventing that 20k bill (through the dealership, not 3rd party). Remember, BMW has to prove that your modifications caused the issue in order to deny your claim. So, if you do your research before and go in guns blazing (respectfully and tactfully), then I think you have a good chance IMO.
__________________

2013 F30 328i: MHI Big Turbo, GFB DV+, Mishimoto CAI, ER TIC/CP/Catless DP, AWE Touring Quad Exhaust w/ Resonated Midpipe, NGK LI Plugs, BM3 with PTF Stage 2 91 AGG Tune, Fuel-it Stage 2 LPFP, Solowerks S1 Coilovers, and DEPO/M-Sport Retrofit
Appreciate 0
      11-01-2018, 11:00 AM   #75
qualicas
New Member
33
Rep
18
Posts

Drives: 2010 135
Join Date: Jul 2015
Location: Calgary Alberta

iTrader: (0)

I had a closer look at the broken parts. I did my quick test and they are almost certainly nylon. BMW likes nylon. The valve cover is Nylon 66 with 35% glass filler. (It said that. I am good but not THAT good) The trick with molding plastics is to use the most cost effective material for the purpose. The lawsuit almost certainly did not question a plastic professional and a lawyer just named a plastic they thought sounded good. If in fact they did start out with Polycarb then wanted to switch to nylon, they would have had to change the mold as shrink for nylon is a lot compared to Polycarb so all dimensions would have been out.
I examined the broken bits and I didn't see any obvious bad design elements.

Interesting my chain is tight, not a bit of slack at all. The tensioner on the exhaust side is all still intact. All the more reason for me to say in my case the chain slipped over the intake sprocket causing the intake tensioner to break.
I had not thought of the start-stop "feature" I would turn it off on any car I owned.
Appreciate 1
Stubok458.00

      11-01-2018, 11:37 AM   #76
BunkerJ
Colonel
BunkerJ's Avatar
1007
Rep
2,382
Posts

Drives: 2013 328i
Join Date: Mar 2017
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by qualicas View Post
I had a closer look at the broken parts. I did my quick test and they are almost certainly nylon. BMW likes nylon. The valve cover is Nylon 66 with 35% glass filler. (It said that. I am good but not THAT good) The trick with molding plastics is to use the most cost effective material for the purpose. The lawsuit almost certainly did not question a plastic professional and a lawyer just named a plastic they thought sounded good. If in fact they did start out with Polycarb then wanted to switch to nylon, they would have had to change the mold as shrink for nylon is a lot compared to Polycarb so all dimensions would have been out.
I examined the broken bits and I didn't see any obvious bad design elements.

Interesting my chain is tight, not a bit of slack at all. The tensioner on the exhaust side is all still intact. All the more reason for me to say in my case the chain slipped over the intake sprocket causing the intake tensioner to break.
I had not thought of the start-stop "feature" I would turn it off on any car I owned.
Interesting. Thanks for that. I know that they did replace it with a different composition but I'm not 100% sure what design changes there were.
__________________

2013 F30 328i: MHI Big Turbo, GFB DV+, Mishimoto CAI, ER TIC/CP/Catless DP, AWE Touring Quad Exhaust w/ Resonated Midpipe, NGK LI Plugs, BM3 with PTF Stage 2 91 AGG Tune, Fuel-it Stage 2 LPFP, Solowerks S1 Coilovers, and DEPO/M-Sport Retrofit
Appreciate 0
      11-01-2018, 10:48 PM   #77
meltbox
Private First Class
23
Rep
124
Posts

Drives: 2014 328xi GT (F34/N20)
Join Date: Sep 2018
Location: Michigan

iTrader: (0)

https://www.pacermonitor.com/public/...LLSCHAFT_et_al

I have been using this to follow the class action... The case is pretty early along though. At this point they're still sort of "setting up" so to speak. Might be a few years before anything comes of this.
Appreciate 1
      11-02-2018, 09:47 AM   #78
BunkerJ
Colonel
BunkerJ's Avatar
1007
Rep
2,382
Posts

Drives: 2013 328i
Join Date: Mar 2017
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by meltbox View Post
https://www.pacermonitor.com/public/...LLSCHAFT_et_al

I have been using this to follow the class action... The case is pretty early along though. At this point they're still sort of "setting up" so to speak. Might be a few years before anything comes of this.
Yeah, they haven't hit trial yet but it seems the judge is already dismissing part of the case, so we'll see who remains on.
__________________

2013 F30 328i: MHI Big Turbo, GFB DV+, Mishimoto CAI, ER TIC/CP/Catless DP, AWE Touring Quad Exhaust w/ Resonated Midpipe, NGK LI Plugs, BM3 with PTF Stage 2 91 AGG Tune, Fuel-it Stage 2 LPFP, Solowerks S1 Coilovers, and DEPO/M-Sport Retrofit
Appreciate 0
      11-04-2018, 04:36 PM   #79
qualicas
New Member
33
Rep
18
Posts

Drives: 2010 135
Join Date: Jul 2015
Location: Calgary Alberta

iTrader: (0)

Update. Yesterday I was going to set the intake cam to the adjustment point. I turned the crank back about 30 degrees to keep pistons from hitting valves.
The timing chain was just jumping over the intake sprocket. I then just turned the cam back. Then I noticed some shinny bits by the cam bearings. I pulled one cam cap off. Totally galled away. Unfortunately, those bearings are just machined in the head no bearing inserts. So that means new head for sure! Damn
To make matters worse, now I think I had better pull off a main and rod bearing just to see if they are galled as well. My oil analysis showed okay but if oil wasn't flowing well it might not have flushed crap into the oil pan.

Now I am thinking, maybe the oil pick up screen was plugged causing low oil pressure, maybe for a while and staving the cam bearings. Maybe that caused a much higher drag on the timing chain and that caused the chain to skip causing everything else.
Looks like I won't get away cheap on this fix, either a head or most probably entire engine.
Attached Images
 
Appreciate 2
      11-05-2018, 03:52 PM   #80
RMachuca3d
Lieutenant
RMachuca3d's Avatar
256
Rep
506
Posts

Drives: F30 328i Msport
Join Date: Aug 2018
Location: WA

iTrader: (2)

Garage List
Ouch
Appreciate 0
      11-05-2018, 11:48 PM   #81
canman111
Private
14
Rep
50
Posts

Drives: F30 328i RWD
Join Date: Apr 2018
Location: Australia

iTrader: (0)

Garage List
2014 BMW 328i  [0.00]
Does anyone have a pre 01/2015 n20 which doesn't have an orange/brown timing chain guide?

Or are they all that colour due to discolouration.
Appreciate 0
      11-06-2018, 12:10 AM   #82
qualicas
New Member
33
Rep
18
Posts

Drives: 2010 135
Join Date: Jul 2015
Location: Calgary Alberta

iTrader: (0)

The color of the tensioners is probably a function of how often oil is changed. I know insides of engines with 15K oil changes are almost Brown while 5000 mile changes are almost free of discoloring.
Appreciate 0
      11-06-2018, 03:09 AM   #83
canman111
Private
14
Rep
50
Posts

Drives: F30 328i RWD
Join Date: Apr 2018
Location: Australia

iTrader: (0)

Garage List
2014 BMW 328i  [0.00]
Quote:
Originally Posted by qualicas View Post
The color of the tensioners is probably a function of how often oil is changed. I know insides of engines with 15K oil changes are almost Brown while 5000 mile changes are almost free of discoloring.
Reason i ask is because im sitting at 2014 production year. Im hoping the new updates came in to effect 2013 as per service bulletin, but am doubtful as majority of people say 2015.

Real OEM when i change between e.g. 2012 and 2015 shows same parts so there is no way to no for sure whether you have the updated parts or not.

Considering whether its worth to have to pay my mechanic to pro-actively change out all the parts since the timing chain issue would lead to engine replacement. $$$
Appreciate 0
      11-06-2018, 09:52 AM   #84
BunkerJ
Colonel
BunkerJ's Avatar
1007
Rep
2,382
Posts

Drives: 2013 328i
Join Date: Mar 2017
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by qualicas View Post
The color of the tensioners is probably a function of how often oil is changed. I know insides of engines with 15K oil changes are almost Brown while 5000 mile changes are almost free of discoloring.
He's referencing the change in color. The pre-2015 guides appear much darker than the post-2015 ones. (Despite mileage) I think the pre-2015 ones either came as an orange or similar color or stained much easier.
__________________

2013 F30 328i: MHI Big Turbo, GFB DV+, Mishimoto CAI, ER TIC/CP/Catless DP, AWE Touring Quad Exhaust w/ Resonated Midpipe, NGK LI Plugs, BM3 with PTF Stage 2 91 AGG Tune, Fuel-it Stage 2 LPFP, Solowerks S1 Coilovers, and DEPO/M-Sport Retrofit
Appreciate 0
      11-06-2018, 04:16 PM   #85
qualicas
New Member
33
Rep
18
Posts

Drives: 2010 135
Join Date: Jul 2015
Location: Calgary Alberta

iTrader: (0)

Quote:
Originally Posted by BunkerJ View Post
He's referencing the change in color. The pre-2015 guides appear much darker than the post-2015 ones. (Despite mileage) I think the pre-2015 ones either came as an orange or similar color or stained much easier.
Have a look at my pictures on page 3. The parts look dark yet when you look at the broken part you can see White inside. They all started as "natural".
There was no reason to color the parts. In the molding business, we usually buy resin either as natural or Black. They just picked up the color as time went on.
Appreciate 1
sspade1553.50

      11-06-2018, 04:23 PM   #86
rjdnyy224
Brigadier General
rjdnyy224's Avatar
United_States
1548
Rep
3,205
Posts

Drives: 2013 328i xDrive
Join Date: Jun 2017
Location: New Jersey

iTrader: (0)

Quote:
Originally Posted by qualicas View Post
Have a look at my pictures on page 3. The parts look dark yet when you look at the broken part you can see White inside. They all started as "natural".
There was no reason to color the parts. In the molding business, we usually buy resin either as natural or Black. They just picked up the color as time went on.
So the whole "later models have white guides" is bogus? I've also seen people mention that they only started implementing the "revised guides" in 2015, but by that time the N series engines were being phased out in favor of the B series. Not sure what to believe, and honestly, part of me is skeptical they revised the guides at all lol. I'm sure there's a document somewhere that will quickly disprove that, but it's just what pops into my head when reviewing the forums for the timing chain stuff.
__________________
2013 328i xDrive N20 8AT | Bootmod3 Stage 2 OTS 93oct | Bootmod3 8AT TCU flash | VRSF Street 5" HD Front-Mount Intercooler | VRSF Catless Downpipe | 2.5" custom exhaust cutout | M Performance Exhaust | NGK L/I Spark Plugs | Dinan 20" Wheels Wearing Michelin PS4S's | Dinan Springs and Bumpstops | F80 Style Decklid Spoiler | Debadged | F80 Style Grille | Various Interior Bits |
Appreciate 0
      11-06-2018, 04:26 PM   #87
BunkerJ
Colonel
BunkerJ's Avatar
1007
Rep
2,382
Posts

Drives: 2013 328i
Join Date: Mar 2017
Location: San Diego, CA

iTrader: (0)

Quote:
Originally Posted by rjdnyy224 View Post
So the whole "later models have white guides" is bogus? I've also seen people mention that they only started implementing the "revised guides" in 2015, but by that time the N series engines were being phased out in favor of the B series. Not sure what to believe, and honestly, part of me is skeptical they revised the guides at all lol. I'm sure there's a document somewhere that will quickly disprove that, but it's just what pops into my head when reviewing the forums for the timing chain stuff.
If that's the case that they're white, then they must stain easier. BMW revised the guide and chain supposedly.
__________________

2013 F30 328i: MHI Big Turbo, GFB DV+, Mishimoto CAI, ER TIC/CP/Catless DP, AWE Touring Quad Exhaust w/ Resonated Midpipe, NGK LI Plugs, BM3 with PTF Stage 2 91 AGG Tune, Fuel-it Stage 2 LPFP, Solowerks S1 Coilovers, and DEPO/M-Sport Retrofit
Appreciate 0
      11-06-2018, 04:29 PM   #88
sspade
Brigadier General
sspade's Avatar
United_States
1554
Rep
4,035
Posts

Drives: F30
Join Date: Oct 2017
Location: Folsom, California

iTrader: (2)

Garage List
2014 BMW 328i  [5.00]
Quote:
Originally Posted by canman111 View Post
Reason i ask is because im sitting at 2014 production year. Im hoping the new updates came in to effect 2013 as per service bulletin, but am doubtful as majority of people say 2015.

Real OEM when i change between e.g. 2012 and 2015 shows same parts so there is no way to no for sure whether you have the updated parts or not.

Considering whether its worth to have to pay my mechanic to pro-actively change out all the parts since the timing chain issue would lead to engine replacement. $$$
Im in the exact same situation. 62k miles currently and counting... fast.
__________________
BMW 328i FBO, Bootmod3 Stage 1
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 03:26 PM.




f30post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST