The N13 is a 1.6 l 4-cylinder turbocharged petrol engine with direct injection. It has an aluminium engine block, vacuum controlled turbocharger and variable valve timing – usual stuff. You can find it in the BMW 1 series F20 and in the 3 series F30. To top of that this engine was also available in some of the Mini Cooper models. In these cars its known as the N18 (or N14 which is the older version of it) and it has some minor modifications from which the most obvious is a different position of the unit under the hood.

To top of that as most of you already know, this engine was developed not only by BMW but also by the French PSA group. So, you can find this unit and its different variations in many different French cars as well.

But to simplify the things I will mention only the N13 BMW version of this French/German engine.


Removing engine plastic cover ? Take your time !

To look at the engine a bit more closely it’s important to remove the plastic engine cover. But! There is a small vacuum tank built into this cover and there is also a vacuum line which goes into this tank. This means that if you don’t unplug the line, you will break off the small connection piece on the tank and you will have to buy a new or a used engine cover.

Ignition coils, Spark plugs – who cares?

The ignition coils can of course fail together with the spark plugs causing misfires, but that’s nothing special.

In this engine it’s good to replace the spark plugs every 40 000 km!

Valve cover & PCV

Next there is the valve cover. The first issue related to this part is the valve cover gasket which can leak oil, but that’s again nothing special and it’s a cheap fix. 

The second issue on the other side is a bit special, since it’s related to the PCV system. The usual PCV membrane is basically built into the valve cover – the membrane will crack over time causing misfires and even excessive oil consumption, which is not good. But luckily you can buy an aftermarket PCV membrane and replace it separately. pcv membrane itself for sale This can solve the PCV issues, but sadly not always. Not always, since the valve cover has two additional small valves built into it – so even if you replace the main PCV membrane itself, you can still sometimes experience the same PCV related issues because the 2 valves can be faulty / or the channels in the cover can be clogged. In this case you will have to replace the whole valve cover anyway, so in many cases it’s simply not worth it to replace just the PCV membrane itself.

Turbo & related stuff

The turbocharger itself is not known for premature failure, but on higher mileage cars or on the more abused cars it can of course break. On the other side, what will definitely break prematurely is the stuff around the turbocharger! Specifically:

  1. The turbo intake hose often cracks – this can cause various symptoms but in many cases you won’t notice anything. However, if you are really unlucky then there is a possibility that a piece of hose gets sucked into the turbocharger and destroy it. (symptoms: uneven engine running, loss of power)
  2. The plastic pipe which connects the turbo intake hose to the PCV will crack too. This pipe gets brittle over time so it’s a good idea to replace it even preventively. (symptoms: vacuum leak/misfires, uneven idle)
  3. The turbo diverter valve can fail – this valve which is bolted to the turbocharger has a rubber membrane in it, which will crack over time causing various power related issues. But it’s very easy to replace it so you can consider replacing it preventively as well. (symptoms: loss of power/limp mode+boost related fault codes stored)
  4. Failure of the turbo vacuum solenoid can occur too – causing power related problems. This solenoid is located on the other side of the engine, it’s well hidden specifically under the intake manifold. So, it seems like the fastest way to replace it is from under the car. (symptoms: loss of power/limp mode+boost related fault codes stored) To top of that it’s also good to check the vacuum pipes for cracks!

Lastly there are 2 harmless but annoying issues related to the turbocharger:

Friction wheel – the hell is that?

On the front of the engine (between the crank pulley and the water pump) you can find a thing called the friction wheel drive or friction gear, whatever. All you have to know about this friction wheel thing is, that it drives the water pump and it can fail causing a specific metallic rattling noise.

Accessory belt & stuff – better to have that shit in good condition !

On cars which are equipped with an automatic gearbox its very, VERY important to have the accessory belt and the associated parts in good condition. Why? Because if the belt breaks or shreds, then it can easily damage the automatic gearbox oil cooler lines – which are positioned very closely to this belt. In this case the ATF fluid will obviously leak out and you will have to replace the expensive lines. To top of that, if you don’t notice this in time then you will damage the gearbox itself as well!

Electric coolant pump – no big deal

Next, it’s good to know that there is an additional electric coolant pump mounted in front of the engine which can fail or leak. So, check it and be ready to replace it. (failure symptoms: drivetrain malfunction message with a stored fault code: 20A608 / P15CD)

Timing chain

All of these engines are equipped with a timing chain which is mounted on the front. If you are lucky and if you don’t have an early production engine, then the chain can last even 200 000 km. But this is not a rule of thumb, so be ready to replace the whole mechanism at around 150 000 km or even earlier. Why? Well, because at 150 000 km:

  • the chain tensioner will be most probably pushed out too much already
  • the chain will be stretched
  • the plastic chain guides will start to wear out as well

If you ignore this, then the chain eventually jumps and in the worst case it destroys the engine, “no big deal”. (Also, if the chain jumps then you can get Vanos related fault codes too) But luckily, it is possible to actually measure the chain wear with a simple tool, which you insert instead of the chain tensioner. So I would highly recommend to measure the chain wear at least after 100 000 km or after buying!!!

tool to check chain

how to check timing chain wear video

As usual it’s also good to check for suspicious rattling noise from the chain.

on the next page: Oil Consumption, Oil & Coolant leaks + other issues


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