BMW N20 Timing Chain

Updated September 29, 2026

The BMW N20 is a 2.0-liter turbocharged four-cylinder used in the 328i and other BMWs from 2011 into the late 2010s. Early builds had plastic timing chain guides that could break down and let the chain skip teeth, which can destroy the engine. BMW’s settlement bulletin covers cars built through February 2015. A chain job runs into the thousands.

Most pages on this topic sort N20 cars by model year. BMW’s own bulletin sorts them by production date and by VIN, and that difference decides which cars the settlement covers. Below: which cars, what the failure looks like, what it costs, and how to shop for one.

Which BMWs have the N20 engine?

The N20 went into the 2 Series, 3 Series, 4 Series, 5 Series, X1, X3, X4 and Z4, plus the X5 xDrive40e. Wikipedia’s N20 entry lists the Z4 (2011 to 2016), X1 (2011 to 2015), X3 (2011 to 2017), F30 3 Series 320i (2012 to 2015) and 328i (2011 to 2016), F32 4 Series 420i and 428i (2014 to 2016), F10 5 Series (2011 to 2016), F22 2 Series 220i and 228i (2014 to 2016), X4 xDrive28i (2014 to 2017), 3 Series Gran Turismo (2013 to 2016) and the X5 xDrive40e (2016 to 2018).

Wikipedia also lists the N20 in a Chinese-market Brilliance MPV for 2015 to 2017, which US buyers can ignore. Model year alone does not tell you the engine, so check the VIN or the engine label on the car in front of you.

What is the N20 timing chain problem?

BMW’s own bulletin says plaintiffs alleged the timing chain and oil pump drive chain modules could fail suddenly. The bulletin, SIB 11 02 21 (revision dated 2021-09-21), states that plaintiffs "alleged that the timing chain and oil pump drive chain modules in certain MY 2012 to MY 2015 BMW Class Vehicles’ are defective and could lead to sudden engine failure and a loss of power to the vehicles." It adds that BMW "expressly denied any wrongdoing," and that the bulletin is a notice of a settlement repair benefit, "NOT a notice of a Recall or Service Action."

Top Class Actions summarizes the allegation this way: "The polycarbonate guide assembly for the timing chain can become brittle and break apart, creating debris that can get lodged in the crankshaft drive sprockets." Wikipedia describes the same mechanism, with "defective polycarbonate compositions" letting guides "break down and deteriorate," slack in the chain, and "catastrophic damage to the engine."

The case was Gelis v. BMW. The bulletin says the settlement has the court’s final approval and took effect on June 30, 2021.

Which N20 build dates are covered?

The settlement covers N20 and N26 cars built through February 2015. The bulletin says: "The remaining vehicles that were produced on or after 3/1/2015 are not included in this Settlement." Cars produced on or after that date were simply outside the case. That is a coverage line, and it says nothing either way about how a later car will perform.

The bulletin also states that the model list is "for informational purposes only, it is not the only deciding factor," and it tells dealers to check a VIN-specific vehicle comment. Production windows in the bulletin run, for example, from September 13, 2011 to February 28, 2015 for the X1 xDrive28i and from October 19, 2011 to February 28, 2015 for the 328i sedan.

What did the settlement cover, and is it still available?

The bulletin’s repair coverage applies to a car with "less than 8 years or 100,000 miles in service," a rule that most covered cars have now passed. CarComplaints describes the terms: for repairs already paid for, reimbursement of "100% of the invoice amount" within 7 years and 70,000 miles, with independent-shop caps of $3,000 for timing chain repairs and $7,500 for engine failure, and a sliding scale "up to 8 years or 100,000 miles" that pays from 75 percent down to 40 percent. The BMW bulletin sets the limit for its repair benefit as "less than 8 years or 100,000 miles in service (whichever comes first)."

A car first put in service in February 2015 or earlier reached 8 years in service in February 2023 or earlier. By the bulletin’s own rule, that puts it outside the repair benefit. No page we read says the program has closed, so ask a BMW center to run the VIN and tell you what, if anything, applies.

What are the warning signs of a failing N20 timing chain?

The most consistent sign in the sources is a rattle or clacking from the front of the engine at start-up. FCP Euro’s N20 guide describes "a rattling or clacking noise coming from the front of the engine on start-up." YourMechanic’s general timing chain page lists a check engine light, a "rattle from the engine compartment at idle," "loss of acceleration and responsiveness," and an engine that will "turn over but not start."

A related item on RepairPal’s 2013 328i tensioner page: "A worn tensioner will give the timing chain too much slack, and this may lead to a slapping noise, especially when first starting the engine." RepairPal also warns that "the sound of timing chain slap is similar to a tapping lifter at startup, so many times they are not replaced because the sound goes away after a few moments." A noise that fades after a few seconds still deserves a look.

Not every failure announces itself. One NHTSA owner complaint for a 2013 328i says "Timing chain tensioner failed clogging the oil pump with plastic which in turn starved the engine for oil. We got a low oil pressure light in the Interstate at 70MPH." The same owner says the engine seized about 10 seconds after the low oil pressure light came on.

What happens if the N20 timing chain fails?

A skipped chain can bring pistons and valves into contact, and the engine can lose power or stall. CarComplaints’ report of the December 2020 settlement says the failure causes "the chain to skip teeth on the chain sprockets," and that "power will be lost or the engine’s pistons and valves will violently collide." YourMechanic notes that "if the timing chain is stretched badly, your vehicle can stall in traffic causing a hazard."

NHTSA’s complaint database for the 2013 328i lists 288 complaints in total across all systems, and several describe timing chain failures. One reads, "Timing chain guide assembly and oil pump drive chain failed catastrophically."

How much does an N20 timing chain replacement cost?

Published national data puts a general timing chain job at $2,120 to $2,764, and FCP Euro reports a dealer estimate for the N20 job of "upwards of $5000." RepairPal’s national timing chain estimate, updated September 3, 2026, shows labor of $1,334 to $1,957 and parts of $786 to $807. That figure covers all vehicles, not the N20 specifically.

FCP Euro’s guide says the job "requires several specialty tools and a wealth of wrenching experience," and that at a dealership the labor alone "will be between 10-15 hours, causing the cost of the job to be upwards of $5000." It adds that the dealer could have the car "upwards of a week." That is a parts seller’s estimate of dealer pricing, not a quote from a shop. The labor time explains why a BMW quote can sit above the national band.

A tensioner-only quote is a smaller job than a full chain, guide and sprocket replacement. RepairPal notes that when a tensioner has failed, "there may be damage to the timing chain guide rails or engine front cover." If a quote is close to the tensioner figure, ask exactly what is included. Our timing chain replacement cost guide explains how the scope changes the price.

What should you ask when buying a used N20 car?

Ask for proof that the chain, guides and oil pump drive chain were replaced, and get the VIN checked. Here is a short sequence:

1. Confirm the engine. Ask a BMW center to confirm the engine and the production date from the VIN. Cars built through February 2015 fall inside the bulletin’s coverage window.
2. Ask for service records showing a timing chain, guide and oil pump drive chain module replacement, with the date, mileage and invoice.
3. Ask a BMW center to run the VIN and report any settlement or warranty comment. The bulletin says eligible cars carry a VIN-specific vehicle comment.
4. Cold-start the car yourself and listen for a rattle or clacking from the front of the engine for the first several seconds.
5. Pull the codes and look at the oil pressure and check engine lights on the dash.
6. Pay for an independent pre-purchase inspection, and negotiate the price with a chain job in mind if no records exist.

Accelerate Auto Repair and Collision’s founder, asked what he would tell a niece buying a 10-year-old BMW, said unless it has ultra low mileage and a very good vehicle history report, the answer is no, that oil leaks are the first thing to check on older BMWs, and that a buyer should not trust the person on the lot. In one shop story he told, a 2011 BMW 3 Series had been quoted a timing chain for a check engine light; a second opinion found sensors unplugged or plugged into the wrong spot, no codes after they were rewired, and the chains were fine. A check engine light needs a real diagnosis before anyone replaces a chain.

Which N20 should you buy or avoid?

Pick a car with documented chain work, or one built on or after March 1, 2015, if you want the lowest paper risk. Skip an undocumented 2012 to early 2015 build unless the price covers a full chain job. The March 2015 line comes from the bulletin’s settlement scope, not from a finding that later cars are safe, so treat a later build as "outside the case," not "cleared."

Common questions

Is the BMW N20 a bad engine? The timing chain guide problem is the one covered by BMW’s settlement bulletin. BMW denied wrongdoing in the settlement, and the bulletin notes it is not a recall.

Is the N26 affected too? Yes for the settlement. The bulletin covers N20 and N26 cars, including PZEV/SULEV versions of several models.

Is a tensioner-only repair enough? Not always. RepairPal says that when a tensioner has failed, "there may be damage to the timing chain guide rails or engine front cover," so ask exactly what a quote includes.

Does a check engine light on a BMW always mean a chain problem? No. In the shop story above, a 2011 BMW 3 Series was quoted a chain for a check engine light, and the chains were fine once the unplugged sensors were rewired.

Can BMW dealers see whether my car is covered? The bulletin says eligible cars carry a VIN-specific comment in BMW’s warranty inquiry system, so a BMW center can look it up.

Do other N20 problems exist? Yes. Our BMW N55 reliability guide notes that a separate BMW bulletin, SI B11 14 17, concerns N20/N26 linkage pins.

Bottom line: If you are shopping an N20 built through February 2015, get proof the chain, guides and oil pump drive chain were replaced, or price the job yourself.

If you own or are buying a BMW around Rowlett, Accelerate Auto Repair and Collision offers BMW repair at 3002 Century Dr, Rowlett, TX 75088. The team includes ASE Master Certified and ASE-certified technicians. Call (469) 501-5115.