Timing Chain Issue - Common or not

I saw the extended warranty info about the timing chain potential issue in the N20 engine. Is it common or rare? Not sure how the poll works but I will try.


1- Yes, it happened to me

2- If yes, what mileage?

3- No, it did not happen to me

4- What is your mileage?

Perhaps common only here. BMW X1 production through 2017 is a bit more than a million units. Fan forums are self-selected.

No. 65k miles on 2013 X1 sDrive28i M-sport

I've talked to techs at BMW dealers and independent shops who have commented on many failures of the earlier N20 black timing chain guides. The ones that didn't destroy the engine received the upgraded white guides. The later white guides seem to be less prone to premature failure.

No....137k

Mine was replaced on goodwill from my dealer. Paid 20% of the total invoice (around 800$). 108k KM x1 2012. It was starting to whine. Not like the videos you see online, but still noticeable.

2015 - 90k , no issues yet

No, 2014 with 48K miles

The million dollar question is does the chain fail then the guides or do the guides fail then the chain. Yes chains stretch but that is why they have a tensioner.

Timing chains are under very little relative stress, ie I seriously doubt it takes 5 or even 10 horsepower to open and close your valves under normal driving. My friends motorcycle puts out more horsepower than my last car and it all goes through that chain driven sprocket to the wheel. It also gets covered in dirt and everything else on the road. These are the chains you expect to break at some point right?

Now when I look at pictures of the N20 chain guides and especially where they break, they look extremely weak. In my humble opinion all chains will stretch, the tensioner will take up the slack provided it doesn't fail itself, but when the cheap plastic guide breaks it's game over.


I can think of 4 types of failure we need to distinguish:

1)design failure: the part has flawed design and all parts built to this design will fail as designed eventually

2)manufacturing failure: 99.9% reliability in manufacturing would mean 1 in 1000 will fail for example

3)maintenance failure: not changing the oil, using wrong type of oil, contamination in oil

4)secondary failure: chain driven oilpump fails and destroys timing chain and or guides.

I also wanted to add that this is something I also looked into extensively on this car and on my last Mercedes where a lot of hysteria around timing chains also existed.

In my opinion, the great thing about the chain is that even if you are a 1/1000 or whatever the actual statistic failure is, they chain does have tell tail signs for this engine if it is about to fail and thus you should be very concerned. A loud whining noise from the lower engine bay caused by the oil pump chain drive about to go is one, a chain slap in the crank case is another, it can set an engine code if the timing becomes incorrect from stretch or tension issues, if you change the oil yourself and you notice plastic in it from grinding chain guides, there are a lot of things and even when people say "it just failed without warning" does that sound like something you would tell your wife even when you kind of knew something was up. Perhaps.

This failure is very rare but also very devastating. The problem is that even being pre emptive like I like to be is extremely expensive for this job as well and you can really guarantee that the person doing the work doesn't brake something else or something goes wrong. As a DIY it is next to impossible unlike the belts which is unfortunate.

I guess for your poll all I an answer is that it has not happened to me and I have high mileage ~110k miles I believe the tensioner was updated and that might be a good idea to change before you are out of warantee

Nope, no problems. 110,350 km's on the dial.

Originally Posted by wvadam

I also wanted to add that this is something I also looked into extensively on this car and on my last Mercedes where a lot of hysteria around timing chains also existed.

In my opinion, the great thing about the chain is that even if you are a 1/1000 or whatever the actual statistic failure is, they chain does have tell tail signs for this engine if it is about to fail and thus you should be very concerned. A loud whining noise from the lower engine bay caused by the oil pump chain drive about to go is one, a chain slap in the crank case is another, it can set an engine code if the timing becomes incorrect from stretch or tension issues, if you change the oil yourself and you notice plastic in it from grinding chain guides, there are a lot of things and even when people say "it just failed without warning" does that sound like something you would tell your wife even when you kind of knew something was up. Perhaps.

This failure is very rare but also very devastating. The problem is that even being pre emptive like I like to be is extremely expensive for this job as well and you can really guarantee that the person doing the work doesn't brake something else or something goes wrong. As a DIY it is next to impossible unlike the belts which is unfortunate.

I guess for your poll all I an answer is that it has not happened to me and I have high mileage ~110k miles I believe the tensioner was updated and that might be a good idea to change before you are out of warantee

I was planning to write up a good long response, but this pretty much covered exactly what I was going to say. The issue is hype'd up because we will hear loudly about the 1 failure, and hear nothing from the 10,000 that don't.

No trouble yet, just hit 150,000 miles on our 2013.

No for me but only have 22,000 miles on a 2014 M Sport. Do you know what the cost would be to change out the tensioner at a dealership? If I don't hear back within a few days, I will give our local dealer a call.

It's funny, I just saw this which is not the same but similar and the way it is handled is certainly not the same.

American Honda Motor Co., is recalling 93,946 model year 2018-2019 Acura MDXs & Honda Pilots, and model year 2019 Acura RLXs, RLX Sport Hybrids, TLXs, and Honda Odysseys and Ridgelines.
The timing belt teeth may separate from the belt, which may result in an engine stall, increasing the risk of crash.
What to do
Honda will notify owners, and dealers will inspect the vehicle and replace any affected timing belt free of charge. Vehicles receiving a replacement timing belt will also have the engine inspected and any damaged components will be replaced for free.
The recall is expected to begin June 1, 2019.

Originally Posted by mickkassem

No for me but only have 22,000 miles on a 2014 M Sport. Do you know what the cost would be to change out the tensioner at a dealership? If I don't hear back within a few days, I will give our local dealer a call.

Not a direct answer to your question, but if you do it yourself, it will cost you about $65. DIY here. My guess is that it would be a one, MAYBE two-hour job for a trained mechanic. Would love to hear what the dealer quoted you.

My 2014 xDrive 28i has 52,000 miles and I haven't had any issues with the cam chain guides so far. Fingers crossed. . .

From what I understand of this failure mode, it's not the cam chain tensioner or the cam chain itself that fails. If that's true, replacing the tensioner as a preventative measure won't help. What fails is the plastic cam chain guides. Sometime around 2015 (there are other threads on this forum with the details), BMW changed the cam chain guides to a new part number with stronger plastic, and maybe a stronger design.

If it's anything like my Honda-built Integra was, you can inspect a Honda timing belt in a few minutes, and probably replace it before lunch, so that job isn't comparable to the difficulty or expense of replacing the N20 timing chain guides.