BMW 320d 3 Series engine with timing chain
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BMW 3 Series Timing Chain: Replacement Interval & Symptoms

If you’re the proud owner of a BMW 3 Series or are simply curious about them, you’re in the right spot.

One component that’s crucial to your car’s health and longevity is the timing chain.

In this guide, we’ll tell you all you should know about the BMW 3 Series’ timing chain: from when it should be replaced to how you can recognize that it may be at the end of its life span.

Let’s get started!

Which BMW 3 Series have a timing chain?

First, does the BMW 3 Series use a timing chain or a timing belt?

The answer is quite simple.

Every single BMW 3 Series model from the E46 generation onwards has a timing chain. In other words, all BMW 3 Series produced since 1997 have a timing chain.

BMW E46 3 Series yellow 330i with a timing chain
BMW E46 3 Series (330i)

For the earlier generations (E21, E30, E36), things were a bit different. Most models had timing chains. But a few, like the BMW 325i (E30 generation), had timing belts.

Specifically, in the E36 generation, only the 316i and 318i models used timing belts, while the rest had timing chains.

In a nutshell? Modern BMW 3 Series (E46 and newer) = timing chains. Some older models = timing belts.

Replacement interval of a BMW 3 Series timing chain

Ever wondered, “How often should I replace the timing chain on my BMW 3 Series?”

Well, let’s address that.

BMW experts generally advise that the timing chain in your 3 Series should be replaced every 80,000 to 120,000 miles. That’s approximately 130,000 to 200,000 kilometers if you use the metric system.

Exposed timing chain in an engine

But what if I don’t clock in those high miles?

Great question!

Even if you’re not driving frequently, time can still wear out your timing chain. So, for those who prefer city drives or shorter routes, consider replacing your timing chain every 10 to 15 years.

Note: It’s fascinating how varied the lifespan of a timing chain can be. Some run smoothly for the car’s entire life, while others might fail way earlier. The secret ingredient? Maintenance.

So, especially after the 100,000-mile mark, getting periodic checks is a good idea. If you’re in doubt or hear any unusual sounds (a bit like a metal rattle), a trip to the mechanic is always a good call.

In the next sections, we’ll dive into how you can avoid untimely timing chain failures and keep your BMW 3 Series running beautifully.

The replacement process: What to expect?

If you’re planning to replace your timing chain or just like being in the know (knowledge is power, after all!), let’s break down what the replacement process looks like for your BMW 3 Series:

  1. Diagnosis: Before any real work begins, a good mechanic will usually run a diagnostic test. This confirms that the timing chain is the true culprit behind any issues you’re experiencing.
  2. Dismantling: The mechanic will need to remove various engine parts to access the timing chain. This includes the valve cover, timing cover, and sometimes even more, depending on your car’s model year.
  3. Replacement: Once they’ve got a clear path to the timing chain, they’ll swap out the old for the new. They might also replace associated parts like the timing chain tensioner and guides if they show wear.
  4. Reassembly: Everything that was taken apart gets meticulously put back together.
  5. Testing: Before returning the keys to you, the mechanic will test the car, ensuring the new timing chain works smoothly and the engine sounds healthy.

It’s a detailed process, and while it might sound a bit intense, in the hands of a skilled mechanic, it’s all in a day’s work.

How much does a timing chain replacement cost?

Ah, the golden question: “How much will this set me back?”

A timing chain replacement for a BMW 3 Series costs anywhere between £1,000 to £2,500. The costs can vary greatly based on your location, the model year, and the mechanic or dealership you choose.

Here are some factors that can influence the costs:

  • Labor costs: Mechanics charge by the hour, and this job can take several hours, especially if complications arise.
  • Parts: Genuine BMW parts might cost more than aftermarket ones. But remember, quality often goes hand-in-hand with price.
  • Additional repairs: If the mechanic spots other issues while they’re in there or if other parts associated with the timing chain need replacing, the costs can add up.

While it might be tempting to choose the cheapest option, remember: the timing chain is vital for your car’s health. Investing in a skilled mechanic and quality parts can save you money (and headaches!) in the long run.

Which BMW 3 Series have a timing chain issue?

Let’s move on to another important question in this article.

It’s pretty unpleasant to know that the lifespan of a BMW 3 Series timing chain varies so widely.

But if you want the lowest chances of timing chain problems, which models should you avoid?

  1. Pre-3/2013 models: If your BMW 3 Series was produced before March 2013, there’s a slightly higher likelihood of timing chain problems as BMW made a small update to the timing chain design afterward.
  2. N20/N26 engines: These engines, placed in BMW 3 Series models from 2011 to 2017, seem to be a touch more susceptible to timing chain troubles. One of the primary culprits appears to be the plastic timing chain guides. Over time, these can fail, which means trouble for the timing chain.
  3. The N47 recall: Then, there’s the infamous N47 engine. Many reports appeared of timing chain issues regarding BMW 3 Series with N47 engines produced between February 2007 and June 2008. In October 2016, BMW officially acknowledged this with a recall.

Learn more: BMW 3 Series: Which Years To Avoid & To Buy? (2024 Guide)

However, before panic sets in, remember: the overall failure rate remains relatively low.

Proper maintenance, timely checks, and addressing any concerns early on can go a long way in ensuring you and your BMW have many smooth rides ahead.

Timing chain in detail

Symptoms of a failing timing chain in a BMW 3 Series

Whether you’re just being proactive or you’ve got a suspicion about your BMW 3 Series’ timing chain, it’s always a smart move to be informed.

So, let’s dive into the signs of a failing timing chain:

  1. Unusual sounds: One of the most common symptoms of a timing chain issue is a rattling or ticking noise coming from the engine, especially during startup. If your car sounds more like a clattering old typewriter than the smooth machine it should be, it’s worth checking out.
  2. Engine misfires: A worn-out or stretched timing chain can lead to the engine’s timing being off. This can result in misfires, where the engine doesn’t run as smoothly as it should. If your BMW feels jumpy or less powerful, this could be why.
  3. Check engine light: Modern cars are smart! If the timing chain is failing, the engine’s computer might pick it up and light up the check engine light.
  4. Metal fragments in the oil: If there’s excessive wear on the timing chain and its components, tiny metal shavings might appear in the engine oil. If you’re getting an oil change and the mechanic spots this, it’s a potential red flag.
A stretched BMW 3 Series timing chain
Example of a (stretched) BMW 3 Series timing chain

Remember, these symptoms don’t automatically mean your timing chain is failing. However, they are signals that something might be wrong.

The best course of action?

If you notice any of these signs, head to a trusted mechanic or your BMW dealership. A little attention now can prevent bigger headaches (and bills) later.

Reader’s tip: BMW 3 Series: 16 Most Common Problems To Check Before Buying

How do you prevent timing chain issues on your BMW 3 Series?

To prevent timing chain issues on your BMW 3 Series, it is important to follow the recommended maintenance schedule for your vehicle and have the timing chain inspected and replaced if necessary.

Some specific steps you can take to help prevent timing chain problems include:

  1. Regular oil changes: Fresh, quality oil not only lubricates the chain but also helps reduce wear and tear. Make it a point to stick to the recommended oil change intervals and always use the type of oil specified for your model.
  2. Use quality oil: Investing in premium, high-quality engine oil can make a world of difference in maintaining the health of your timing chain and its components.

Tip: The 3 Best Motor Oil Choices For A BMW (+ How To Pick One)

  1. Early intervention: Heard a suspicious rattle or noticed any of the symptoms we mentioned earlier? Don’t wait! Addressing potential problems early can prevent more severe issues in the future.
  2. Use premium gas: It’s highly recommended for most BMW models, including the 3 Series.
  3. Periodic inspections: Even if you don’t notice any symptoms, it’s a good idea to have a trusted mechanic inspect the timing chain area during regular service intervals.
  4. Avoid overloading the engine: Overloading the engine can put extra strain on the timing chain, potentially leading to premature failure. It’s also crucial not to drive the car too hard when the engine and oil are still cold!
  5. Avoid running the engine low on oil. Low oil levels can cause the timing chain to run dry, leading to excessive wear and potentially causing the chain to break.
  6. Avoid exposing the engine to contaminants. Debris or contaminants can get into the timing chain area and cause the chain to wear out faster or break.
Filling up car engine oil

Tip: Read our article here to learn more about BMW’s reliability!

Why is the timing chain problem so infamous?

The timing chain is a common worry among BMW 3 Series owners. So, why is that?

Let’s take a look at how the timing chain works and what causes the problem:

Timing chain: A quick overview of how it works

A timing chain is a metal chain that connects the engine’s crankshaft to the camshaft(s). The crankshaft is responsible for converting the reciprocating motion of the pistons into rotational motion, while the camshaft(s) operate the valves in the engine.

The timing chain’s primary function is to synchronize the engine’s functions. It ensures that the engine’s valves open and close at precise times during each cylinder’s intake and exhaust strokes.

Engine timing chain CAD render

In a typical internal combustion engine, the timing chain is located inside the engine and is covered by a timing chain cover. It’s typically subjected to a lot of wear and tear due to the high speeds at which it operates and the heat and friction it is subjected to.

Timing chains vs. timing belts

Both timing chains and timing belts are used to synchronize the rotation of the crankshaft and camshaft(s) in an internal combustion engine.

The main difference between a timing chain and a timing belt is that a timing chain is made of metal and is typically more durable, while a timing belt is made of rubber and tends to wear out faster.

In general, timing chains require less maintenance than timing belts. However, timing belts can be more efficient, quieter, and generally easier to replace.

Why does a timing chain fail?

There are several reasons why a timing chain may fail prematurely. Some of the most common causes include:

  • Wear and tear. Like any other mechanical component, timing chains are subject to wear and tear. As they age, they can stretch and become loose, which can cause them to skip or jump teeth on the gears they are driving, leading to timing issues and engine damage.
  • Lack of lubrication. Timing chains require lubrication to reduce friction and wear. If the timing chain is not properly lubricated, it can wear out faster and fail prematurely.
  • Contamination. If debris or other contaminants get into the timing chain area, it can cause the chain to wear out faster or even break.
  • Poor manufacturing quality. Sometimes, timing chains may fail prematurely due to poor manufacturing quality or design defects.

Conclusion

The good news is that a failed timing chain doesn’t have to be a death sentence for your car.

As long as you maintain your car according to the service schedule, the chances of a failed timing chain will reduce significantly.

That being said, if you find yourself with a timing chain that’s in bad shape, it’s crucial to get it replaced as soon as possible to avoid further damage.

We wish you many more miles in your BMW 3 Series!

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2 Comments

  1. I there, iam wondering if you have heard anything about bmw 320i msport tourer, ihave one that the vanos unit failed causing upwards of 4000 pounds worth of damage to the engine, the car is a 2019 3 series with 33,000 miles on the clock with a full bmw service history.

    1. Hello!

      I’m sorry to hear about your vanos unit issue. It’s quite rare for such a problem to occur, especially with a car that’s well-maintained and relatively new. Unfortunately, I haven’t come across any cases like yours yet.

      Best of luck with the repairs!
      – Patryk

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