Diesel Particulate Filter (DPF) Problems – Symptoms, Cleaning & Replacement Cost

See the symptoms of a clogged Diesel Particulate Filter DPF, how to clean it & how much it will cost to replace it if required.

How to unblock a diesel particulate filter that has a problem

Having a bad or blocked diesel particulate filter can result in various issues and can adversely affect the general performance of your car.

For those who do not know the function of a diesel particulate filter, or where it is located in the car, all that will be discussed in this article. We will also take a look at the symptoms of a clogged DPF, how to clean it and how much it will cost to change one if required.

What is a diesel particulate filter?

A diesel particulate filter (DPF) is a filter designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine in order to reduce emissions from diesel cars. They are sometimes referred to as soot traps.

The particulate matter referred to here includes ash and soot. By trapping these particulate matters, the DPF helps in reducing harmful exhaust emissions as well the black smoke that is common with diesel engines.

From time to time there is a regeneration process that kicks in when the filter is full and burns off accumulated particulate matter making it possible for it to be used again in powering the vehicle.

It has been made compulsory for cars to have DPFs so as to meet up to emissions standards. It is illegal to remove the DPF of your car and If you are caught driving around without one you will face the penalties for going against the law.

The DPF filter is placed in front of the NOx trap which is also referred to as the NOx storage catalytic converter, ahead of the exhaust pipe, but after the first temperature sensor.

If you want to take away the filter maybe to replace it with another one, you will have to remove the grills and plates around it using a screwdriver. When you have taken off the plates, you might also notice some O-rings or other clamps that you have to equally remove.

What are the Symptoms of a Blocked DPF

1. Check Engine Light Alert

If you have a clogged DPF, your check engine light should come on. The filter makes use of sensors to gauge pressure and temperature so if there is an issue, you will be alerted through your check engine light.

As a driver you should already know that if your check engine light should come on, what you have to do is to scan the trouble code memory using a code scanner. This way you can determine what the problem is and handle it right away.

In this case, if after reading the trouble codes you find out that the issue is with your DPF you will then have to decide on the appropriate course of action to take in order to fix it.

2. Increased Fuel Consumption

One sign that something is wrong with your engine is that it will have poor fuel efficiency, consuming more fuel than what would normally have been the case.

With the filter being clogged, more fuel will have to be used by your engine and your engine will burn through the fuel at a much faster rate. You will notice that you now frequent fueling stations unlike before and going by the current price of diesel, this is not a development you will be happy about.

3. Damage to the Turbocharger

Having a bad or clogged DPF can cause severe damage to the turbocharger. This is because the slowing down or the blockage of the flow of the gas can result in a fast rise in temperatures.

This only gets worse if not handled and the turbine housing equally becomes more heated. It can also lead to the carbonization of the oil in the turbocharger and this does not bode well for the motor.

In a situation where the housing gets damaged, it can result in leaks and lead to poor efficiency.

4. Poor Engine Performance

When your exhaust system suffers from a clogged or blocked DPF, your engine will be adversely affected. It will require more power to be able to remove the excess gases and will no longer be able to provide optimum performance because something is wrong.

Your engine will find it very difficult to get rid of exhaust gas and this will result in a build up. This build up will cause the engine to not deliver good performance and you may notice that you can’t accelerate as you normally would.

5. Difficult Startup

Like we already pointed out, a clogged DPF will cause a backup of exhaust and since this back up is not removed, there will be more pressure on the engine. This will make it difficult to start up or it might not even start at all.

The pressure has to be released because if your engine should start up that way, it could lead to serious damage. This is why it is advised that you clean out the DPF so as not to experience a blockage. The saying that prevention is better than cure really applies here.

6. Strange Odor

You may notice some strange smell as the exhaust gas keeps building up in the engine. Apart from the fact that this can be quite irritating, it can also prove to be dangerous to health as it is not safe to breathe in.

It can also be flammable and this poses a great risk of fire accident.

How to Clean a Diesel Particulate Filter

1. Using additives

This method is for those who want to clean their DPF by themselves. There are special additives that break drown soot and ash that can get the job done for you. There are various ones available in the market that you can choose from and a bottle goes for about $13 to $26.

They are not complicated to use,t]]t usually there will be directions on how to use them on the body of the container. What you have to do is to pour in the contents of the bottle into your fuel tank. It is advised that you drive around for about 15 to 30 minutes so that the additive can really get into the system and do its job.

If after using the additive the issue still persists then you should get professional cleaning.

2. Thermal Method

If you’d rather have a professional clean your DPF, the thermal method might be used. This method is also referred to as “bake and blow.”

How this technique works is that the DPF will be placed inside an oven and the heat cranked up. The heat oxidizes the soot and the airflow will expell the ash from the filter.

Diesel Particulate Filter Replacement Cost

Replacing a DPF can be very expensive as you will soon find out which is why it is advised that you maintain it properly. Most people will rather have it cleaned than spend so much in replacing it. But in a situation where it has been damaged, there is no other choice than to replace it.

That being said, replacing a DPF can cost you about $1,000 to $7,000.