BMW N20 Common Problems & Reliability Issues

The BMW N20 is a 4-cylinder, turbocharged engine produced from 2011-2017, and was BMW’s replacement for the naturally aspirated 3.0L 6-cylinder N52/N53 engines. As the outgoing N52 and N53 were reliable engines, the BMW N20 had big shoes to fill, especially given its turbocharged design. Turbo engines are more complex and require several additional components, which means there are more things to potentially go wrong. However, thus far, the N20 has proven to be a reliable engine without a significant number of common problems.

BMW N20 Common Engine Problems

Although the N20 is a reliable engine overall, the earlier models are plagued with timing chain issues that may be costly to fix. Simply because some engine problems are common does not mean they will indefinitely experience issues on every engine. Additionally, N20 engines are susceptible to many other issues that we will not classify as common issues, as they may only pop up on a small percentage of engines. So, what are the most common issues on the BMW N20?

1. Timing Chain

The timing chain appears to be the number one fault on the N20, however, this issue is mostly prevalent on engines and vehicles produced prior to 2015. In January 2015, BMW redesigned the timing chain components, which seems to have significantly reduced the chance of failure. For certain vehicles produced prior to 2015, BMW offered an extended warranty for 7 years/70,000 miles on the timing chain and components.

In the unfortunate scenario where your N20 was not offered the extended warranty or is outside the age or mileage of the warranty, then the timing chain replacement can be a significant cost. In the worst scenario, a complete timing chain failure could potentially lead to engine failure. Generally, independent repair shops charge $1500+ for parts and repair, while the cost at a BMW dealership may be nearly double. This is a relatively tough DIY job, however, the timing chain and components cost roughly $500.

Symptoms of BMW N20 Timing Chain Failure

  • Loud Whining from Engine
    • Typically, very loud and noticeable
  • Significant Scoring on Chain
  • Too Much Slack/Play

The most common symptom is a loud, noticeable whining sound from the N20 engine. Engines may make audible, but quiet whining noises under light revs/acceleration, however, this is unlikely to indicate a timing chain issue. An overwhelmingly loud whine may suggest the timing chain is beginning to fail. Additionally, significant scoring or scratching on the timing chain may point to an underlying issue. Although, some scoring is normal due to age and wear and tear. The same may be said for slack or play in the timing chain; small amounts are normal, while significant slack or movement in the chain may suggest an issue. You may inspect the BMW N20 timing chain by peering through the oil cap.

DIY Difficulty – Intermediate to Advanced

BMW N20 Timing Chain Kit

Cost to Repair N20 Timing Chain & Components - ~$200 DIY, $1000+ indy shop

Mileage – May fail earlier, but usually after 50,000 miles

Other BMW N20 Engine Problems

The timing chain seems to be the most significant issue on the N20, and primarily only affects vehicles produced before 2015. Apart from the timing chain it is tough to come up with any issues that are truly common to the BMW N20. Of course, as engines age and accumulate more mileage there may be some common issues that come up due to typical wear and tear. Here we will review a few issues that may be the most common “wear and tear” problems.

1. N20 Valve Cover and Valve Cover Gasket

As with its larger 6-cylinder turbocharged BMW siblings, the BMW N20 uses a plastic composite valve cover (VC) and a rubber valve cover gasket (VCG). With increased mileage and age the valve cover and valve cover gaskets may become brittle and begin cracking. This is mostly due to the nature of heat cycles where the engine and components heat up and cool down constantly as you drive the car and let it rest for long periods. Once the valve cover and/or gasket develop cracks they will begin leaking oil. Typically, this begins as a minor leak and may not be noticeable until it expands, or additional cracks develop.

Symptoms of Valve Cover and/or Gasket Leaks

  • Visible oil leak
  • Burning oil smell
  • Smoke

Due to the tilt of the engine, this is usually noticeable just below the engine cover on the left side of the engine, when viewing the car head on. Smoke coming from the engine bay will likely become prevalent as the leaking oil may drip onto the extremely hot exhaust or turbocharger. For the same reason, you may notice a burning oil smell inside the cabin with the A/C or heat turned on, without using the air recirculation.

It is unlikely a minor leak will cause any significant issues on the N20, however, over time the leaking oil may cause premature wear on parts such as engine or transmission mounts. Fire may also be a concern as the oil typically drips onto very hot components. The N20 VC and VCG are relatively inexpensive parts at about $300 for the valve cover, gasket, ball pin, shaft seal, 4 damping elements, and 20 bolts. Repairs done at a shop may add up as it is a labor-intensive replacement.

DIY Difficulty - Intermediate

BMW N20 Valve Cover (for BMW N20B20A) - Full kit including valve cover, gaskets, and bolts

BMW N26 Valve Cover (for BMW N26B20A) - Full kit including valve cover, gaskets, and bolts

**We recommend replacing the entire valve cover, especially over 100,000 miles.

N20/N26 Valve Cover Gasket (gasket only)

Cost to Repair - ~$300 DIY, $500+ independent repair shop

Mileage – 6+ years, and 60,000+ miles. May be sooner, or may hold up well past 100,000 miles

2. Oil Filter Housing Gasket

We won’t spend much time discussing the N20 oil filter housing gasket (OFHG) issues. As you may have guessed, it is very similar to the valve cover and gasket. It is a rubber component that is subject to similar wear and tear with age, mileage, and heat cycles. The gasket may begin to crack over time, which will lead to the development of an oil leak. It is also possible the oil filter housing itself develops a crack and subsequent leak, but this is less likely than the gasket alone.

Symptoms of a leaking OFHG are like the VC/VCG, however, the oil leak will be observable in the area of the oil filter housing. The gasket is only roughly $10, while the oil filter housing runs over $300, including the cap, oil filter, and gaskets. The OFH/OFHG also are somewhat labor intensive, so costs may add up at independent repair shops or the BMW dealership.

DIY Difficulty – Intermediate

BMW N20/N26 Oil Filter Housing - Includes housing, filter, cap, and gasket

BMW N20/N26 Oil Filter Housing Gasket - Gasket only

Cost to repair - $10, or $300 to DIY, $500+ at independent repair shops

Mileage – 6+ years and 60,000+ miles. May be sooner, or may hold up past 100,000 miles

Final N20 Wear and Tear Items to Consider

Obviously, as cars age there is no way to tell what will end up failing in the long-run as wear and tear takes a toll on almost all components. However, a few other issues that are most likely include:

  • Coolant Hoses
  • Chargepipe
  • Vacuum lines
  • Vanos Solenoids

All in all, the BMW N20 is a reliable engine and does not have many common issues that warrant concern until higher mileage. For the DIY crowd, a lot of the repair jobs mentioned are not overly expensive as the cost of parts is not too high. For the shop goers, some of the repairs are lengthy and labor intensive so the costs may add up.

BMW N20 General Maintenance

As with any engine, the BMW N20 is also subject to standard maintenance items such as fluid changes and ignition components. We will not discuss vehicle maintenance such as tires and brakes, but rather focus on the maintenance recommendations for the N20 engine specifically. Below is a list, in no specific order, of general maintenance items to expect on your BMW.

1. N20 Spark Plugs & Ignition Coils

These components play an important role in gasoline engines as they are directly responsible for igniting the air/fuel mixture in the cylinder, thereby generating power. Ignition coils transform the car battery voltage into the thousands of watts required to send a charge to the spark plugs. The plugs then create the spark that is required to ignite the air and fuel in the cylinder. Each time a cylinder fires, the associated ignition coil and spark plug must do their jobs completely to generate a large enough spark to generate a full burn, otherwise the engine will lose power. Eventually, due to wear and tear caused by age and mileage, the plugs and coils will no longer work to the best of their ability.

It is recommended the spark plugs are changed every 50,000-60,000 miles on stock N20 engines, while modified or tuned N20’s may require replacement as often as 20,000 to 25,000 miles. On the other hand, ignition coils should be changed every 60,000-75,000 miles on stock engines and tuned engines may burn through them as soon as 30,000 miles.

Recommended Maintenance Interval

Stock Engine: Spark plugs every 50,000-60,000 miles; Ignition coils every 60,000-75,000 miles

Modified/Tuned Engine: Plugs every 20,000-25,000 miles; Coils every 25,000-35,000 miles

Maintenance Cost

Spark Plugs: $65-89 DIY, $120+ at an independent repair shop

Ignition Coils: $159 DIY, $250+ at a repair shop

BUY BMW N20 IGNITION COILS HERE

BUY BMW N20 SPARK PLUGS HERE

2. Engine Oil

Although it is obvious engine oil must be changed as a part of standard maintenance, it is relatively unclear how often. Browsing the forums, a lot of people will suggest 5-7k (thousand) mile oil changes, while others claim 10k, and some claim 15k is acceptable. For a while, BMW suggested changing the oil every 15,000 miles on their newer engines, however, this was revised in 2014 to 10,000 miles. Personally, we believe the cost of engine oil is relatively inexpensive compared to premature engine wear or failure, so we believe 5,000 to 8,000-mile oil change intervals (OCI) are best.

That being said, the oil is long-life approved (whatever that means) and is typically high-quality oil. If you extend a few oil changes to closer to 10,000 miles the engine is not going to suddenly detonate due to old oil alone. Additionally, gentle driving on highways at constant speeds will likely extend oil life, while aggressive driving and/or frequent city driving will likely shorten the life. Your driving style should dictate whether your personal OCI is on the higher or shorter end.

N20 Engine Oil Info

Weights: 5W-30 or 5W-40 recommended

Oil Consumption: ~1 quart per 850 miles

Oil Capacity: 5.3 Quarts (5L)

Recommended Maintenance Interval

5,000-6,000 miles for aggressive driving, or short trips/city driving

7,000-8,000 miles for gentle/moderate driving, or long trips/highway driving

**We highly recommend using LiquiMoly engine oils. It's excellent oil for the price, and is our oil of choice for all 3 of our BMW N54 engines as well as any other turbo BMW.

Maintenance Cost

DIY: Depends on brand, roughly $30-40

Shop: ~$100

BMW N20 LiquiMoly Engine Oil

BMW N20 Oil Filter Kit

**The oil filter should always be changed along with the oil**

3. Engine Coolant

BMW does not clearly state a coolant change interval for the BMW N20 as they claim the coolant is a “lifetime” fluid. Now I am not quite sure if BMW just expects the engine to explode before 100,000 miles so they consider it a lifetime fluid. We recommend flushing and replacing your N20 coolant every 60,000 to 80,000 miles or roughly every 5 years. The coolant itself is very inexpensive, and as such, the DIY crowd may want to change the coolant even sooner.

N20 Coolant Info

BMW approved coolant

Coolant Capacity: 7.1 Quarts (6.7L)

Recommended Maintenance Interval

60,000 to 80,000 miles

OR every 5-6 years

Maintenance Cost

$20 DIY

~$100 repair shop

Final Thoughts on BMW N20 Maintenance and Common Problems

As discussed throughout this article the BMW N20 is an overall reliable engine that does not have many common issues. The timing chain and components may be problematic on models prior to 2015, but has since been resolved with an updated design. Oil leaks from the valve cover/gasket and oil filter housing/gasket may begin to become prevalent prior to 100,000 miles due to wear and tear. Additionally, standard maintenance on the vehicle is pretty minor and inexpensive. Please do keep in mind – simply because something is listed as a common problem in this guide it does not mean it will indefinitely become an issue on every engine. Additionally, because something was not listed does not mean it may not become an issue on certain cars.

Often, reliability of each specific N20 engine may come down to how well it is maintained, as well as the luck of the draw. Some engines may make it past 100,000 miles without any significant issues, while others may cost thousands of dollars a year in repair bills. A well maintained BMW N20 engine should generally be a reliable, inexpensive engine to own, all while remaining enjoyable and sporty to drive.

What are your thoughts and experiences on the BMW N20 reliability?

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40 thoughts shared

  1. Hi
    I own a 2012 x1 powered by n20 -2L engine. The vehicle has poor acceleration from rest and shows a big half yellow engine check light. The engine has done 120 000km on the clock. There is black carbon soot on tail pipe but no visible smoking. What could causing this?

    Regards
    George

  2. Comment author image

    Carlos R Gachassin-Lafite

    says:

    I have a 2012 528i with 80k miles and timing chain colapse now at the BMW dealer they said I need a new engine $7,000 plus labor. Any suggestions . It can fix or I need to replace the engine

  3. I have a 523i am-sport Recently starting bringing up the drive train error on plugging the code error is Vanos exhaust camshaft position not reached,Mechanic suggested changing the vanos exhaust unit will that solve the problem?

  4. Hi my BMW 3201 2012 crank bearing blew, I have to replace the engine with a second hand one.. is it ok to reuse my existing turbo from previous engine?.. thanks Mick..

  5. Hello.
    Wife has a 2013 x3 turbo L4. Its an early model and the vacuum pump has gone out and alot of oil in the vacuum lines.

    The cover had oil in the resivour and was cleaned out. The issue is that there is a vaccume line that extends across the top of the envine and disappears into a wire wrapping with other wires i to the firewall. It is connected to the vaccume line via a tee connector on the turbo side of the engine.
    What is its function and where does it lead? I need to clean the oil out from it.
    Thank you.

  6. Comment author image

    Michael Wright

    says:

    Own a 320i, 2013 with 120,000 miles. Took good care of it, just had to replace the turbo charger then a month later a lower crank bearing appears to have blown. I can’t see spending $10,000 fixing the car but if I can find an engine would it be DIY do-able? I am told that the brand new turbo prob has metal in it because it uses the same oil as the engine so it will need to be replaced. So i would look for an engine with a turbo still attached.
    My main question is can a weekend mechanic pull and replace an N20 engine? 2, Can I replace the N20 engine with one from a 328i? Should it just be junked? Any help?

    Thanks Mike

  7. Comment author image

    Robert Adonizio

    says:

    I have a 2015 328dxdrive. When the car has been on the highway for about a half hour, it starts to shake on acceleration up a hill. When take my foot off the accelerator, it goes away. Around town, or at slower speeds it does not shake. It is not in the steering wheel It seams like the whole car is shaking or fluttering. I had the transfer case and flex disk changed. Did not help. Any thoughts??

  8. After 50000 km and 6 years of soft use my X3 28i 2012 mod. began to have the noise from the time chain. Replaced with a cost of 2000€ . Unacceptable for a car that supposed to be well build and premium .. Sold after a couple of months because temperature issues began to arise..

  9. 2013 328i xDrive purchased in June 2017 with 60 000 miles.. At 70 000 miles in December of 2017 the timing chain and components replaced, transmission oil cooler, thermostat. Now in 2020, the oil filter housing is leaking, as well as the valve cover. Extended warranty was a good investment…to date it cost them $7,300, and there will likely be another $2,500 to follow…Bought the car $22,400 in 2017, is now worth about $13,000, and will have cost about $10,000 in repairs to keep on the road for 3 years. So…the car lost nearly 10 000$ in value for 3 years, cost $10,000 in repairs, plus standard maintenance (brakes, spark plugs, tires, shocks)…NEVER own a BMW without some sort of warranty…Kind of wanted a 340i xDrive, but if I go down that road, I will have to purchase a costly warranty again.

    1. I traded in my 2011 328xi with 97k km for 6k CAD this January, sorry to break it to you,but a 2013 328xi with your mileage would only worth about 10k CAD retail, 8k whole here in Canada

  10. Comment author image

    Neil Woodward

    says:

    As it’s still under dealer warranty it’s going in on Monday for investigation. Oil level seems fine and as its only done 60k I don’t think it’s valve stem oil seals but drives very well so I don’t think the turbo is faulty. My money is on the turbo oil feed pipe (a known fault apparently) or its been over filled with oil and is burning off the excess. Given the smoke is at its worst if the car’s not been used for a while I still think its the oil feed line.
    Will post the investigation results /solution when I get it back.

    1. Have the same issue with my 2013 x1. When not driven for a few days a cloud of bluish smoke on start up. Otherwise don’t see anything.

  11. Comment author image

    Neil Woodward

    says:

    I have a 2013 320i xdrive with 66k on the clock, clouds of bluish smoke on start up if not used for a few days. Runs well so find it hard to believe valve stem oil seals would fail on such a relatively low mileage engine but can’t think of another cause.

    1. Neil ,
      Have you sorted out what was wrong with your BMW?

      Most people say its the oil seal in turbocharger shaft, or inlet/incoming oil pipe to the turbocharger,

      but bluish smoke generally has to do with fuel burning issue,

      As soon as you fix the issue, please share the solution.

      1. Comment author image

        Neil Woodward

        says:

        After 2 weeks at the dealer they cannot find any mechanical faults car drives well with expected power delivery but they did notice it had too much oil, so the level was reduced to just below the maximum and that seems to have cured the issue. Why oh why did BMW dispense with dipsticks. Old fashioned but reliable and easy to use.

        1. Comment author image

          Neil Woodward

          says:

          Dealer confirmed, as, I suspected, that during the pre-delivery service it was over oiled. Reduction of the oil level to the correct amount problem appears to have been resolved. There was a letter in the motoring section of last Saturday’s Telegraph from a guy describing an identical problem with his Porsche Boxster which also turned out to be from too much oil added at a recent service.

    1. Hi Ahmad,

      It’s a good idea to change the transmission fluid every 70,000-80,000 miles. BMW considers it a “life time” fluid which we don’t completely agree with.

      Best Regards,

  12. 2014 328i M-Sport: About 40,000 km DRIVETRAIN warning, during heavy acceleration in rainy weather. Able to continue home at reduced power and speed. Next day started car but warning was gone and engine power was back to normal. Still under warranty. Dealer checked electrical connections and suggested that there had been a contaminated or loose plug. No further problems. At 43,000 km left rear wheel speed sensor went on vacation and triggered ABS, stabilization and flat-tire monitor warnings. That was a $180 fix at the dealer post warranty.

    1. Drive train is a common issue & mostly caused by the fuel injectors leaks inside the engine due to the high pressure fuel pumping, specially it is occurs in the cold start or in the very cold climate, also the injector problems will leads to carbon build up problem,

      1. Hi EMZ,

        You’re right in that leaking injectors may potentially cause internal issues. It’s not good to have un-burnt fuel potentially wiping oil off. As long as the leak is minor and is addressed within a timely manner it is unlikely to cause any harm to the N20. Additionally, I am unsure why you believe a leaking injector would cause carbon build up. First of all, carbon build up occurs on intake valves and it is because N20s are direct injected and fuel is NOT sprayed into the intake ports/valves. Extra fuel would actually help wash away carbon deposits.

        Leaking injectors have absolutely nothing to do with carbon buildup. It’s simply a natural occurrence on direct injected vehicles.

        Best Regards,

        BMW Tuning

          1. Hi Michael,

            There are a few different potential methods to test. It would be a long explanation, so I’d recommend googling “n54 how to test injectors”. Leaking injectors are very common N54 problems so there is a plethora of information out there.

            However, you’ll likely notice when your injector(s) are leaking. Fuel mixture/AFR codes may pop up. You’ll like have a rough idle on cold starts. When a leaking injector is bad enough you’ll notice it in data logs, too.

            Best Regards,

            BMW Tuning

  13. My 2013 328i now has 97,500 miles on it. I bought it with 35K miles, and early in my ownership was the only issues I have had: Bad Fuel Injector, then subsequent Bad Cat. Both were covered on my remaining BMW warranty. Beyond that, I have been keeping up in the maintenance. I have been doing 5K mile oil changes with LiquiMoly 5W-40. My mechanic recently inspected my car and said everything looks good. I will be looking to DIY my coils and spark plugs.

  14. If you have to add a quart of oil every 900 miles then in 4500.00 miles you would have practically change the oil. I don’t get it. Why change the oil every 7k ?

  15. Comment author image

    Hazanizaini

    says:

    i have some problem until now not solve.. the problem is my bmw f10 engine n20 when i drive at 50mph its jerking, for your information i have change all 4 new ignition coil, new spark plug and, high pressure pump . but the problem still same, jerk and sometime drive train will appear on the screen.. and i also change the turbo solenoid. went i diagnos using autoland vedis 2, the fault come misfire cyilinder 3, serval misfiring.. i change 3 times spark plug but still problem…

      1. Assuming the injectors are ok, you need to set the spark plug gap to 0.5mm solved the issue from what we experienced. Recommended gap is too big and new genuine BMW plugs have been coming in at 1.2mm supposedly pre gapped

    1. You said you changed the turbo solenoid? Where is it located on the N20 engine? I cannot seem to find it on my 2014 X3 F25 N20.

  16. I have a 2015 328i xdrive sport wagon. I started doing the maintenance when the free services ended. I have 80k miles and have done everything recommended. I like the wagon bc of my dog mostly but for other reasons too. BMW stopped selling them in US this year so I plan to keep it 200k+ miles. I have heard so much conflicting info on timing chain forever fluids and maintenance intervals I take them all for what they are worth. IMO people who change the oil every 3k despite recommendations, etc do so to make themselves comfortable. This is fine but offers no benefit to the engine. Same with other fluids, things have changed. Also the name brands in most cases are literally identical to no names. I get it, I have a 1975 FJ40 with 22k original miles and I baby the hell out of it. Anyway, if you want it I wouldn’t hesitate bc of high miles.

    1. Comment author image

      Kevin Rainbolt

      says:

      hello everyone, I have a 2013 328i M-sport with the N20 engine. When I come to a stop(hard or slow) the car shakes really bad and will sometimes just shut off all together. With my MAF unplugged, it’ll bog down a little bit, but not shut off. I’m wondering if anyone is having this issue?(my valve cover gasket needs to be replaced and has leaked a substantial amount overtime. I’ve been working too much to have it taken to a shop or repair it myself) I have the valve cover gasket already and plan to replace it in about 2 days when im off work.

      My car has the auto stop/start feature. With that being said, with it turned off, the car still shakes really bad(when at optimal temperatures) and either shuts off entirely, or engages the stop/start. Any suggestions?

  17. Comment author image

    Richard Blais

    says:

    Great write up. Thank for this information. My wife got her sister’s 2013 x3 28i this week with 111,000 kilometers or about 70,000 miles. No whining noise or oil leaks. My BMW mechanic (we have a Z4) says that the chain will be a problem, not if. He did say to pay attention to new noises and then have the chain replaced for a cost of ~$4,000. He is a European shop. My local non-bmw car mechanic said he wouldn’t touch it.
    Thanks again from Ottawa Canada.