Changing your car’s air filter is one of the easiest pieces of preventative maintenance you can perform to make sure your engine is running smoothly. Here, we will run you through replacing the air filter on a Volkswagen Polo 1.4 TDI 9N Twist. It should take no longer than 10 minutes and can be done by even the newest of beginner car enthusiasts.
There’s very little that can go wrong here, with the worst thing being dropping a screw and losing it, but they can easily be replaced with a quick shop online. The air filter is also shaped so that it will only correctly fit into the car, so let’s get stuck in, shall we?
If you’re performing a full service on your VW Polo 9n, you might need to know how to replace the fuel filter. We have a guide on that, too.
Tools you will need
The only thing you need is a good screwdriver and a replacement air filter, the screwdriver set I have is the Ifixit Manta Precision Bit set, it’s never steered me wrong when I needed a set of smaller bits.
The air filter I ordered from Euro Car Parts was the Audura Air Filter and only cost around £6.50. There are other brands of Air filters available to you, such as the Bosch Air Filter, if you fancy something a little more high-end.
If you are using a service like Euro Car Parts and you’re worried you are buying the wrong part, you can enter your car’s registration, and it’ll only display parts that fit it. Replacing air filters is very similar, no matter what your car is, so you can still follow along if you have a slightly different car and are confident you can adapt. But this is a very easy process, and you’re already smart enough to come to Cars For Beginners for help, so I’m sure you can manage.
Method summary
Should you be in a rush, we have condensed the whole process into a few easy steps. You can read on if you need us to expand on any of the steps.
Find the air box inside the engine, usually to the right on most Polo engines like the 1.4 TDI.
Use a Phillips screwdriver to remove the two screws, and unhook the left side of the cover.
Disconnect the MAF sensor connector if you need more space, though it’s not required.
Lift out the old filter and place the new one in the same spot; clean the air box if needed.
Hook the cover back on, screw it in place, and reconnect the MAF sensor if it was unplugged.
How to change the air filter on a Volkswagen Polo 9N
As we have mentioned, changing the air filter is a very easy process. It doesn’t require any kind of in-depth knowledge. If you know how to use a screwdriver and can manage to remove two scores, then you have this in the bag. We are a beginner-focused site, so I’m going to be explaining things along the way. You might just find yourself learning a little more about cars.
Locate the Air Box.
First, you need to locate the air box inside the engine. On the 1.4 TDI engine (and most Polo engines), the Air Box is to the right of the engine and has a long tube protruding from the left side heading into the intake manifold. Please excuse this particular Polo, which is disgusting; it is 20 years old, after all.
It’s worth noting that if your Polo’s air intake does not look like this, you may have an aftermarket air intake, but more on that later.
Unscrew the air box cover
This is exactly as simple as it sounds; there are two screws on the right side of the air box cover. You need an average-sized Phillips bit to get these unscrewed; there are plenty of bits that fit these screws in the Ifixit kit we mentioned earlier. Sometimes these screws can seize if they get too rusty; if so, apply some WD-40 or other penetrant to help loosen the screws.
Remove the air box cover
This step is also pretty self-explanatory; hooks hold on the left side of the air box, so you need to unhook them after you have removed the screws from the right side of the cover.
Remove the MAF sensor if you need more room
There’s no need to remove any of the air hoses that connect to the air box cover, but you can remove the connector for the MAF sensor if you want to give you some more room to push the air box cover over whilst you change the filter. Note that this is entirely optional.
Remove the old air filter from the air box
Insert the new air filter
Install the air box lid
Reconnect the MAF sensor if you previously unplugged it
Remember, if you unplugged your MAF sensor connector to plug it back in now, if you leave it out, it’ll cause a whole host of problems for your car’s engine. Mainly misfires, rough running, and low fuel economy. Some cars just straight up won’t run.
What if I have an aftermarket air intake?
If you find that the air intake and filter do not look like how they do in our photos, it could be one, that you have a different car, or you might have an aftermarket intake.
Aftermarket intakes or “Cold air intakes” are usually fitted to supply more air to the engine to increase its power. There is a lot of debate on whether or not cold intakes help with power, but that’s an article for another day. Your air filter may be in the shape of a cone. In that case, you may want to look for replacement air filters from Ramair or K&N if you want high-quality.
FAQs
Here we have outlined some of the most common frequently asked questions around replacing a VW Polo air filter.
You should change your car’s air filter annually, or every 15 – 30k miles, depending on what comes first. Generally, filters are part of a car’s annual service package.
The Air filter is located at the top right of the engine bay under its cover called the Air box. You can tell it’s the Air box because it has the word “filter” written on it, and it contains an air filter diagram with arrows indicating airflow. It’s pretty hard to miss, The Air box has a large pipe protruding from the left-hand side of the box to the engine’s induction system. This is also where the MAF sensor sits.
The air filter helps to filter debris and dirt out of the air going into your engine. If dirty air gets into your intake manifold or combustion chamber within the engine, it can cause a lot of problems. These can lead to engine failure if not addressed. So, it’s just best to keep on top of your air filter.
Dirty air filters become dense with particles and heavily restrict air flow to the engine, your MAF will try to compensate for this, but eventually, your engine will choke and become rich, and then you will notice misfires and rough idling. Inspecting your air filter is the best way to assess its condition, it’s not hard to get it out and take a look.
All finished
That’s it! That’s all you need to do to replace an air filter on a VW Polo 9N. Wasn’t hard at all, was it? If you want to know more about beginner-friendly car maintenance tips, we have a page on that. If you enjoyed this experience, we guarantee you’ll love that. Replacing your air filter is just one part of the general annual service that your car should undergo, if you want to perform this full service, you have to change other filters, as well as the oil in your car.
