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N20 Timing Chain failure Drivetrain malfunction. BMW F25 X3 2013 53,000 miles

141731 Views 348 Replies 115 Participants Last post by  ExGMan
My wife's 2013 X3 just stopped and gave a drivetrain malfunction error in the middle of the road while she was driving.

I was unable to move it and could not push it.

I tried the emergency electronic release but after 20 minutes realized no matter what I did it would not work.

Then I remembered the manual release screw under the car!

This video helped.... But I had to remove the panels underneath with a 8mm socket to gain access to the Allen wrench screw.

Let me say..... what a pain in the ass!

Finally got the car out of gear and towed home. To make matters worse warranty just expired 3 months ago, car now has 53,000. I swear BMW does this on purpose.

No I am trying to diagnose the problem..

I am hoping its something simple... I have seen where the ignition coils have failed locking out the transmission to prevent damage...

ANy help would be appreciated. I cant believe how dangerous this car is designed. I was stuck in one spot for 1 hour trying to disengage the gear lock. I hope this helps someone else. The car was unable to be moved or towed until the lock is disabled.

Anyone have any idea on what it could be?...

The timing chain and or timing chain guards failed resulting in a total loss of the engine.

I have had many people with the BMW N20 issue email me of similar failures and am keeping a list here...

Please add your comments to this forum if you had a similar experience.


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That was oil filter housing. Some cars came with plastic version, which cracks letting coolant and oil to mix. Oil turns to slush, coolant gets dirty too.
Great BMW did the right thing.

Apparently, engine oil managed to 'break' through some part (made in plastic then but metal now) and went into the radiator causing the cylinders to seize in the engine.
Would you mind to elaborate on the above? What do you mean by "they broke"? If they break something they have to fix it. And how can one break a filter housing? Was it plastic version? Thanks
....oil contamination since I replaced the filter housing they broke during a routine oil change
Well, that might be because Magas was 53,000 miles - just a month or two after warranty ended. Now guess how that would turn if his car was 63,000, or better 73,000. That warm and fuzzy ""BMW stepped up and is completely covering the repair" most likely would not be there.
How long is pedal shoulder, about 6'', i.e. 1/2 foot, right? When you step on it with your 200lb body weight it generates 100lb/f torque. When you hit it hard, it make much more, maybe even 200lb/f that the chain should deliver to back wheel. Still, they work for long year...

All chain does in the engine - turns 2 cam shafts. Each cam is probably 1'' tall. Only 1 cam pair is engaged on each shaft at any point in time. That is it. RPMs are way higher, but torque is much less than in bicycle. Thus the chain has no reason to stretch beyond 0.01%.
This chain breaking issue reminds me alot of bicycle chains that stretches over time and then breaks.
No, do not warry.

Timing chain issue is simple to recognize by two symptoms:
1 - "Drive-train malfunction" message
2 - $20,000 check for engine replacement. (sometimes paid by BMW if in or close to warranty period)
is it something to do with timing chain?
Yardney, you are right with your notes. Percentage is low, I would even say very low. But percentage is statistics, and statistics is a science of large number. If you have 1 or 2 cars in garage, statistics do not apply to you. People above also in the same pool with same statistics, but guess what - their engines a ruined. This proves that whatever low percentage number is does not prevent you in particulate from having that catastrophic problem.

Another observation: I noticed that mostly N20 chains fail on a)X3 and for owners living in b)Canada.
It maybe that this is a function of temperature and engine load (X3 heavier).
If one has 328 in Florida, he may never see this problem. Same with mechanics: maybe Canadian dealers repair broken chains 3 a day, but Florida mechanics did not see any yet. Thus an opinion of a single mechanic is questionable.
1. I believe (almost) all recent failures are on X3. At the same time bunch of 320/328 are on the road with the same engine. So it is (may be) function of load.
2. As I notice, Most of X3 failures are from Canada. It might be because Canadians are all rich and more bimmers are sold there (Canada is probably 1/10 of USA population), or N20 is temperature sensitive as Canada is colder.

I have N55 and N20 in garage, interesting is that it takes N20 2 times longer to warm up to optimal temperatures than N55 when it is cold outside. Well, N20 eats less fuel, thus warms up slower. You know that VANOS and chain tensioners are oil driven, and when it is cold oil is thicker. So maybe that is the relation...
my question is does this problem occurs to all X3 (2012-2013) from mileage 50k - 100K ?

Here you go, 2014:
I have simply deduced that 2014 is likely not affected from the fact that every report is of a 2013, with no documented 2014s.
That is true. I already posted my observations: by stats N20 sedans are much large present than X3, but X3 show higher failure rate than sedans. Also I noticed that Canadian presence in X3 failures is quite significant. So it can be function of load and/or temperature.
Interesting. That thread, while long, has a much lower number of actual failures than are reported in this thread.
Last page of that bulletin: "Covered under term of the BMW New Vehicle Limited warranty... or CPO". So if you are out of original warranty - that is a useless paper. If in warranty - they would fix it with or without the bulletin. Thus no change to nothing, or correct me if I see it wrong.
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