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DPF and Regen's

Posted on January 30, 2018 at 1:15 PM Comments comments (0)


By Joel Ilton on Friday, 24 February 2017

As diesel engines have evolved, and vehicle emissions have been monitored heavily, manufacturers have been employing more and more 

One of these systems is the Diesel Particulate Filter (DPF) which sits in the exhaust system and filters harmful carbon particulates produced in the combustion cycle, preventing these particles from being released into the atmosphere.

First fitted to diesel vehicles from 2007, the DPF has been causing confusion and, in many cases, expensive repair bills for drivers, due to lack of knowledge about the system.

The filter is designed to deliver an 80% reduction in diesel particulate and soot emissions and does this by trapping the particles in the filter itself.

The engine control unit (ECU) monitors the saturation level inside the filter, and when it reaches a certain percentage, increases the temperature inside the exhaust to ‘burn off’ the particles.

The procedure for your vehicle’s DPF regeneration process, as well as all the information on the system, will be located in your owner’s handbook.

DPF Regeneration Methods

There are three different types of DPF regeneration methods:

Passive Regeneration

Active Regeneration

Forced Regeneration

Passive Regeneration

Passive regeneration takes place automatically, with no warning lights coming up on the dashboard.

It mainly occurs on highways, when the vehicle speed and exhaust temperature is high.

Depending on how the vehicle is used however, this may not be possible. Stop-start driving, or around town trips will not allow the exhaust to get up to temperature to carry out this regeneration.

Active Regeneration

Once the ECU reads the soot loading has reached a certain limit (usually around 45%), it will instigate what is known as post combustion fuel injection.

This procedure injects a small amount of fuel into the engine after the main combustion cycle, to increase the temperature in the exhaust and trigger the regeneration process.

The ECU will usually flash the DPF light on the dashboard to alert the driver that the regeneration process is in progress.

Depending on your vehicle, you will need to keep your vehicle over a certain speed and engine RPM until the light has stopped flashing.

The procedure should be covered in your owner’s handbook, but a round guide is to keep the engine speed over 2,000RPM and the vehicle speed over 60km/h.

Depending on the saturation level, this process may take anywhere from 5 minutes up to 25 minutes.

You may notice increased fuel consumption, the cooling fans running constantly and a slight acrid smell from the vehicle during this period. This is normal, as the exhaust temperature reaches over 600 degrees to burn off the particles.

If the process is interrupted and the regeneration cannot be completed, the ECU will activate ‘Reduced Power Mode’ or ‘Limp Home’ mode.

This will limit power to prevent any damage to the engine or exhaust systems.

The DPF and Engine warning lights will both come on when the vehicle enters this mode.

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Forced Regeneration

If the DPF and Engine warning lights come on, the final regeneration will need to be completed.

This is known as a forced regeneration.

 The vehicle will need to be driven carefully or towed down to a manufacturer dealership to have the DPF manually regenerated.

 This process is carried out by connecting a diagnostic scan tool to the vehicle and forcing the vehicle to carry out a regeneration.

This can be a costly exercise as the oil and oil filter will require changing after the service has been completed. This is due to the extra fuel that is added after the combustion cycle, as some of it works its way into the sump, and dilutes the oil.

Prevention of DPF replacement

Depending on how blocked the DPF is, it may be the case that these regeneration procedures cannot clean the DPF completely.

The only way to carry out complete removal of particles is to remove the filter from the car and have it professionally cleaned, or replace the filter altogether.

This is an extremely expensive exercise, as replacement DPF units can cost many thousands of dollars!!

What can prevent normal regeneration taking place?

Frequent short journeys, such as stop-start city driving, that do not allow the engine to reach correct operating temperature

Using the wrong oil type – DPF equipped vehicles require oil of a ‘low Ash, low Sulphur’ grade, to prevent excess build-up occurring

An issue with another emissions control device, such as the exhaust gas recirculation (EGR) system, or a problem with the inlet or fuel systems

Low fuel level – most vehicles will not carry out a regeneration cycle if the fuel level is under ¼ of a tank

Overdue service interval – low oil quality or level will prevent regeneration from occurring

Engine warning light on – a warning light or a diagnostic trouble code stored in the ECU may prevent regeneration

DPF additives

Some manufacturers have special additive systems to supplement the DPF system.

These usually include injecting a small amount of liquid – usually Cerium Oxide – to the fuel mixture, to allow regeneration to occur at lower temperatures.

This additive is usually located in a separate tank next to the fuel tank and is usually topped up during logbook service operations.

If your vehicle is not fitted with this system, there are many aftermarket fuel treatments you can purchase and add to your fuel tank to carry out the desired effect.

Always check with your vehicle manufacturer before using these products, as some may not be compatible with your vehicle.

When purchasing a diesel vehicle, it is important to check and see if it is fitted with a Diesel Particulate Filter, and whether your driving style will allow the system to be used to its full potential, or cause you headaches and expensive repairs in the long run.


Posted on January 5, 2018 at 3:10 PM Comments comments (0)

Did you ever notice how nice people are during a snow storm?  

Happy New Year

Posted on December 29, 2017 at 6:45 PM Comments comments (0)

Happy New Year to all.  Please keep those diesel trucks running.  Add Total Power to your fuel and drain your air tanks (as per manufactuer).  Maybe it's time to check your air dryer too. Call us Tuesday.  We will be back to work at 7:30 AM.

Welcome Rony

Posted on December 27, 2017 at 3:50 PM Comments comments (0)

We have some new faces at K&M TRUCK and AUTO REPAIR.  Please welcome Rony Montero and Mike Gully to the light/medium duty division.  :)

Holiday Toy Drive

Posted on December 1, 2017 at 7:30 PM Comments comments (0)

K&M TRUCK and AUTO REPAIR has partnered with ECNY Foundation to bring a little joy this holiday season through the “Gifts on The Ground” initiative. Last year this program provided gifts for over fifty veterans and their families. In addition they were able to provide over two-hundred under privileged families with gift bags full of presents at a holiday breakfast event.

This year the goal is to provide gifts for over three-hundred children, teens and adults from the Sunshine Prevention Center and Kids Clubhouse of Suffolk.

We will have a donation box located in our customer waiting room until December 15th to accept toys, gloves, scarves, hats, socks or gift cards. If you have any questions about the Sunshine Prevention Center please visit www.sunshinepreventionctr.org and Kids Clubhouse of Suffolk at www.kidsclubhousesuffolk.com.

Thank you for your support.



Posted on November 28, 2017 at 3:25 PM Comments comments (0)

Did you know that K&M TRUCK and AUTO REPAIR is equipped to repair your light duty vehicles?  Building 1 holds 5 bays including geared to cars, light and medium duty trucks.  Our new techncian, Loren, is a master gasoline technician.  So whether it's part of your fleet or the family car why not bring it to K&M TRUCK and AUTO REPAIR?  

Welcome New Technician

Posted on October 31, 2017 at 11:40 AM Comments comments (0)

Please welcome James Stewart Sr. to the staff at K&M TRUCK REPAIR. James will be our 3rd technician in the heavy duty department. He comes to us with many years of experience in truck and bus repairs. DOT inspections are his forte and we hope that he will be a great asset to our customers in preventing unnecessary DOT tickets.

Daylight Savings Time Ends Sunday, November 5th

Posted on October 20, 2017 at 11:35 AM Comments comments (0)

It's time for K&M TRUCK and AUTO REPAIR to check these key maintenance items.  With winter coming, be sure to increase visibility and safety.  Change your wiper blades.  Check that all lights are working and that you have the appropriate reflectors.  Check that your coolant is rated for the type of weather you'll be encountering.  Check your antifreeze and coolant levels.  Change the coolant filter.  Add diesel therapy to the tank and change your fuel filter.  Air dryers and/or cartridges should be changed and conditioner added to the system.  Batteries, cables and terminals should be checked, cleaned or replaced.  K&M can help with all these items.  Call today for an appointment.  631-331-0066

Meet our new Service Advisor

Posted on October 13, 2017 at 10:00 AM Comments comments (0)

We would like to welcome Anthony Baiardi to the Service Department at K&M TRUCK REPAIR, INC. Anthony will be working alongside Ray Frey in the front office to help provide improved customer service. If your vehicle is light or medium duty, you will be working with Anthony.

Anthony comes to us from a local Dodge dealership and has been in the automotive field since 2013 working at both dealerships and parts distributers. Since starting at K&M he has been vigorously training on our policies, procedures and production software. His next phase of training will be in voice and facial recognition! He finds it amazing that our employees know our customers as soon as they walk in the door or call on the phone and he is determined to acquire that skill!

Anthony is committed to great customer satisfaction and will be focusing on preventing your fleet from unnecessary down time. As he becomes more familiar with our customers he will be reaching out to you by phone, email or quick visits to assure you are receiving the right services from K&M TRUCK REPAIR.

Please Welcome Anthony the next time you are in our office.

Light and Medium Duty Tech Wanted

Posted on July 12, 2017 at 8:30 AM Comments comments (0)

Help Wanted.  Looking for diesel techs, Light, Medium and Heavy Duty.  We offer really competivie salary, Simple IRA lot's of Paid Time Off.  Please come down and check us out.