Egr coolers, Diesel Engines, Natural gas engines, and Westport Innovations

One of my first jobs at a dealership in Ontario was to replace EGR coolers.   EGR coolers are found in pretty much every diesel engine.  They are there only to reduce emissions.   I'll try to explain it as best i can, EGR stands for exhaust gas recirculation.   It simply recirculates exhaust gas that has been cooled in order to reduce NO2's. ( Nitrous Oxides)  The EGR is controlled by the engine ECM which controls the EGR valve that determines how much recirculated exhaust gas can enter the air intake.   During this process the exhaust gas is cooled
Imagine and egr cooler as one tube containing  two seperate  pipes; one pipe carries coolant; and the other pipe carries hot exhaust gas. the coolant pipe will cool the hot exhaust gas.

   Now egr coolers are constantly failing and a sign of this is coolant in the air intake.  A common sympton is white smoke or missing coolant.  You really should not lose any coolant at all; especially a new truck; so small amounts missing daily could be a possibility.

So why am i mentioning all of this, well on top of an EGR valve and EGR cooler to reduce emmisions in North America new trucks also must have either DPF (diesel particulate filter) or DOC  and they can range from large ceramic filters to  a huge assembly hidden underneath the passenger side step.

here is a great illustration of how it works

 http://www.freightlinertrucks.com/TruckInnovation/Clean-Drive-Technologies/Emissions-Technology

What they don't really tell you is that egr coolers fail alot.  Moreover,  the apparatus  that the diesel particulate filters come in are huge.  some of them weigh up to at least 500 lbs.  Its pretty ridiculous all the crap that's underneath the truck just to reduce emissions.

This phenomenon would also explain why the used truck market for trucks old enough that dont have this crap is really high.  Ive seen old trucks which basically are garbage get sold for ridiculously high prices because the buyer doesn't want any of the  hassles that are with emissions.  You don't have to pull over to the side of the road and do a regeneration.  A regeneration is basically the truck heating of the diesel particulate filters so hot that it burns out all the soot (inside the filter ) and at the end of this time consuming ordeal your filter dpf (diesel particulate filter ) should be unplugged.



Which leads me to Natural gas engines, why are they coming back in popularity ? Basically as everybody knows natural gas is very cheap now so there is a cost benefit. A Canadian company called Westport Innovations re-designed the fuel system of a diesel engine to run on Natural Gas.   I've seen some trucks already at the dealership, its a cummins ISX engine with a revamped fuel system.   I think the most important thing that a lot of people dont realize is; its such a clean burning engine that it doesnt even have an emission filter of any kind.   So not only have you eliminated at least 500lbs of emission related crap, that hangs off the bottom of the truck.   you will not have to pull over to the side of the highway and do a regen.  Nor will you have to pull into a dealership and have the diesel particulate filters get changed because they are all plugged up.
   So what is the downside to these engines?  Ive heard that they require valve adjustment more frequently (big deal)  more importantly would be the lack of re-fuelling stations but i believe that has been changing albeit very slowly.
  Basically Natural Gas engines are here to stay and its because engine manufacturers cannot reduce the emissions of a diesel engine.