N20 timing chain rail coming apart

 Here’s a hot topic with a lot of BMW owners,,,,this car came in with check engine light on and engine whine and rattle noise,,,,check engine light was low oil pressure and jammed oil pressure ,,,,,I noticed the timing chain whine but the engine was also rattling,,,,I removed the valve cover to inspect the timing chain,,,,you can see the chain rail missing and jammed under the vanos unit. So I removed the oil pan to see what’s going on inside and this is what I found at the bottom of the oil pan,,,,there was so much plastic from the timing chain rail,,,there was also a broken bolt and metal shavings in the pan. There was so much plastic in the oil pan that the oil pump was sucking up pieces of plastic causing a oil pressure issue and causing more damage.

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177 Responses to N20 timing chain rail coming apart

  1. concerned says:

    Hi Andraes, has BMW field engineers offer any explanation how this whole mechanism failed? Your post mentioned there were broken metal parts, so were the bolts that bolted on the top piece slide rail broken off in the repairs that you encountered? Or the failure started at the two snap-on tabs that connect top slide rail to the right-side guard rail?

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    • Most of the failures I have seen start with the two snap tabs for the timing chain rail breaks

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      • concerned says:

        The N55 timing chain rails have similar snap tab design too, and N55 timing chain has not quiet made the news all these days ….

        From the N20 parts diagram, the top slide rail is bolted on by two bolts, the right guard rail also has 2 bolts. So the two snap tabs should not bear weight/force, correct? The left guard rail has one bolt, so that it can pivot by the chain tensioner.

        Did most of the failures result in shattered top slide rail? One speculation is that the factory torque spec of the 2 bolts for top slide rail are incorrect, leading to the failure. Is that possible?

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      • We were told from bmw the problem is the timing chain weak link and the plastic was also weak,,,so they updated both and made them stronger

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      • Aaron says:

        Hi there. I’ve just gone through this painful experience myself. BMW offered me 20% off a brand new engine. Still $17,000 for an x1 thatvisnt even worth that. Anyways I spend 20 hours replacing the chain. Big job. Went well and all seemed good. The car ran for a mile or so then seized. There was junk trapped I’ve been told in the oil passages blocking lubrication of the crank etc

        Found a low mileage used engine for $4800. You suspect these class action lawsuits will come to fruition? BMW must be accountable for this. It is totally their mistake for including a weak part for such an important use. I will never buy another BMW as they have not helped me financially and refuse to take responsibility.

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      • You never know about these class action suits,,,I totally understand you leaving BMW

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  2. concerned says:

    So BMW knows all along the early N20/N26 has weak chain link and weak plastic …. BMW better makes things right for their customers.

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    • That why they did that 7/70 for certain models and years

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      • concerned says:

        A dealer foreman listened to my N26(almost 7 years and 60k+ miles) and said there was no whine. He also opened engine oil cap and checked that the timing chain + slide rail(engine just turned off) was tight with no snag. My trusted mechanic also listened to the engine and said it sounded quieter than other N20/N26 timing chains that he fixed. The cold chain + slide rail has a slight play, maybe 1-2mm.

        My 7 yr/70k will expire end of this Oct(in a couple of weeks). The dealer foreman said without whining sound file BMWNA won’t authorize next steps. He did suggest to authorize diagnostics($200) so that the shop can dump car data to BMW headquarter to further evaluate. Do you think it is worth paying $200 to do this?

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      • Nope,,,,I have never heard of car data for further evaluation,,,if they took a look and said everything looks ok,,,,I would hold on to my $200 dollars

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  3. concerned says:

    Thanks for saving me $200!

    I have told the SAs and foremen to check timing chain in the past dealer oil changes, they just informally listened and looked, and said all was good. None of my complaints was on paperwork, the SA said to get the complaint on record, I had to pay $200 diagnostics before they will put anything on paper. Oh well.

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  4. luigi Borgese says:

    Hi, This is a great site!! I have an april 2013 f30 320i m sport this is an N20 engine I believe. I’m a little concerned about an underlying knocking. The more you drive it the less you hear it but it’s mostly present on idle. Not sure if it could be chain issue or rod bearing or just the way the car is to be honest. The car has done just over 30K Motorway driving is absolutely fine and after a long drive you can’t usually hear anything. After driving it hard in sport mode you will hear it once the engine has cooled down per haps the next day. Interested in your thoughts. Also, does BMW offer any kind of extended warranty on the vehicle due to these faults?

    Thanks

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    • Ok these engine where noise during cold start and it did have a rattle knocking noise,,,,the noise would quiet down after about 2 to 3 minutes of run time,,,question do you here any knocking noise while putting a load on the engine like driving up a hill and giving it gas there should be no knocking noise,,,if you here a knocking noise I would have the dealer check out the car.,,,BMW does sell a extended warranty it is not cheap.

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      • luigi Borgese says:

        Thanks.. I’ll check this but whilst driving it’s fine I don’t think there is any knocking going on when i’m driving but only on idle Sometimes mostly after a decent drive say 45mins you can hardly hear anything.. I checked the chain from the oil filler cap and was able to move the chain side to side on the chain guide about 3-4mm it doesn’t seem overly loose. Is that slack normal? Can’t see any signs of metal filings in the oil either.

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      • Yes that slight movement in the timing chain is normal

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    • Nathan says:

      I’ve got exactly the same issue with mine, yet to be found by several mechanics, I’m unsure what it is

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  5. luigi Borgese says:

    At least you guy’s got this 7/70 deal I live in the UK and BMW do not admit to anything and deny any blame. We do not have any 7/70 come back at all. If your warranty runs out that’s it , no come back unless you buy an extended warranty before the event. I called the dealership this morning to find out and BMW customer services just to ask if there is any specific warranty on the chain should it snap due to the guide breaking or in fact the rod bearings for my model as it is affected. They denied that there was any such problem and also told me that the chain and guide is not part of any service schedule at or before 70K I guess we should all wait until it snaps and destroy our engines before we have it done….. very surprised at their reply I must say.not sympathetic in any way.

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  6. Sean Warner says:

    Hello I have a 2013 328i xdrive(72k) that I just had the timing chain, guides etc. Replaced proactively by BMW(was not having any issues), and I think they put 0w30 oil in my engine instead of the 5w30 I’ve been using, do you think that’s better for the engine, I live in upstate ny, thanks alot

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  7. Luigi borgese says:

    I’m wondering if this thumping could be the clutch or flywheel. It sounds like that’s where it’s coming from. Is it possible at this mileage?

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    • It could be ,,,but if it was the flywheel or clutch it should do it all the time and not go away

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      • Luigi borgese says:

        Yes, tricky to work out. But it sounds just like that kind of ping. Clutch seems fine no vibration or variation in noise with clutch engaged or disengaged . I was thinking play in the flywheel. Strange also noticed if the car is parked on a upward gradient the noise is slight. If it’s level then it’s likely to be a bit louder. But the more you drive it the less you gear it.

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      • Does the noise go away when you depress the clutch pedal,,,,because that would put pressure on the flywheel.

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  8. Luigi says:

    No, depressing the clutch has no effect at all. I think i’m Barking up the wrong tree . I took the car out yesterday and couldn’t hear a thing. I am wondering if fuel pressure has anything to do with it. When the fuel tank is full it seems to dissapear.

    I could hardly hear it even when the engine was cold. Could it be the high pressure pump on the head?

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    • It could be,,,they do make a knocking noise normally.

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      • Luigi Borgese says:

        I actually think that’s causing the noise. You can here that soft kind of cam noise at the same frequency on all the N20’s for some reason on mine there are times when it’s harder and louder when i’m lower on fuel.
        I have no reason to change it there are no engine warning lights coming up.
        Wasn’t there a re-call on these?
        If you replace one does it need pluging into for a valvetronic re-learn update or is it just a like for like mechanical replacement including the relating fuel lines?

        Apart from warning lights how can you tell if this is running propert? Can this make acceleration less smooth?

        Would be interested to know. Thanks…

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      • No there was no recall on the high pressure fuel pump on a N20,,,the only way to know if it is going bad would be because of a check engine light coming on for the high pressure fuel pump,,,replacing it is just straight replacement no programming.

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  9. Luigi borgese says:

    Thanks, i’ll keep my eye on it . Think this is causing the pinging i was concerned about

    Like

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