Urea – More Things to Consider

Urea - More Things to Consider

I recently heard a new concern for those of you who will be storing and dispensing Urea for the 2010 diesel trucks. Urea is a very corrosive product that can quickly damage metal tanks, some types of seals, even dispensing nozzles.

Most fuel dispensing nozzles are made from nickel plated aluminum. When Urea is dispensed through such a nozzle, the nickel plating will react changing the Diesel Emission Fluid (DEF) to where it can cause damage to the SCR (Catalytic Converter) system.

The longer the Urea is in contact with the nozzle the more potentially damaging the fluid will become. What this means is that in high volume situations, the fluid will have limited contact with the nozzle and the likelihood of fluid being contaminated is significantly reduced. In lower volume situations where there may be extended periods of time between use, there is a higher likelihood of contaminating the fluid.

It may be desirable to go to a nozzle made of unplated metal or possibly even a composite material to prevent this contamination.

It is considered vital that a non-fuel nozzle be used to prevent the possibility of accidentally adding diesel to the DEF or DEF to the Diesel Fuel. Either mistake will likely cause rapid and catastrophic failure of the engine and or the SCR System.

In Europe a company called ElaFlex provides the defacto standard for AdBlue (Urea) nozzles that have a unique feature that prevents the AdBlue (Urea) from being added to the fuel tank.

ElaFlex has recently signed an agreement with OPW to provide these nozzles to the US and Canadian markets.

We will be providing a comprehensive list of suggestions on how to safely and cost effectively dispense Urea for your fleet operation.

Diesel Doctor

Copyright 2009 – William Richards

Coolant Problems in 2007 and Newer Diesel Engines

Coolant Problems in 2007 and Newer Diesel Engines

The 2007 and newer medium and heavy duty engines with the new emissions devices are creating new and potentially serious problems for cooling systems in general and coolants in particular.

With cooling loads increased by as much as 30% over the previous engines we are seeing issues that must be understood and addressed by users.

As trucks have become more aerodynamic the underhood area has been reduced and airflows restricted. At the same time we have larger displacement engines often with higher horsepower density, plus EGR systems recirculating greater volumes of very hot air together with other heat producing, exhaust restricting Emissions devices.

We have seen trucks with fiberglass hoods that have warped or melted from this tremendous heat load.

All of this places more heat into the coolant, and not only more heat, but higher average temperatures.

Many of today’s coolants are excellent products, however they need more monitoring and more maintenance than ever before.

In the past many fleet experts and OEM’s would recommend an annual check of the coolant. Today these high loads can use up the additive package found in coolants in weeks rather than months. We have seen instances where coolant is properly checked and found to be in good condition, yet in less than a month it can be worthless.

We have seen coolant actually turn black, not from contamination, but simply from continuous high heat loads. Silicate drop out and gelling is more prevalent than ever before.

When this coolant begins to deteriorate the cooling system can be damaged very quickly. We are seeing radiators and heater cores that the solder has been eaten away by the coolant. We are seeing far more liner and even block cavitation problems than ever before.

As a result we have some suggestion and recommendations to try and protect your engines and cooling systems.

Check coolant with fresh Test Strips or Refractometer at every oil change or quarterly, whichever comes first. (Note: Old test strips can give inaccurate readings)

Use only fully formulated coolants from reputable sources for top-offs, and replacement. There is now a huge problem where some suppliers are purchasing used ethylene glycol from manufacturers that had used it in the manufacture of made-made fabrics. They then try to filter out the contaminants and then they use substandard additive packages to make what they claim is new antifreeze from virgin product. This is usually a poor to very poor quality product. It will look OK and a level 1 or 2 test might not show a problem. However a level 3 or 4 test done by a reputable lab will show real and potentially damaging problems.

Never top-off with just water. Coolant works best at a 50%-50% to 50%-70% mix. If it gets out of spec, it will not work properly, and can actually cause expensive damage.

In our opinion all diesel engines in medium and heavy duty applications should have coolant filters.

If you decide that have buy concentrate and mix it yourself, get a mixing system and install either a de-ionizing system for the water or use distilled water. Contaminants in some tap water can render the coolant useless. (See item 2)

You should use only the coolant recommended by the OEM. Do not mix colors especially OA (orange) and OAC (red) with anything.

If you have a failure where oil gets in the cooling system or where you have silicate drop-out or silicate gelling, you need to flush the system with an acid type cleaner and neutralizing agent. If you don’t spend the time to do this procedure, you will have continuing cooling system problems.

Use SCA additive as required to bring the coolant back to the OEM specification.

If you have a problem where you need to make the same repair over and over, get some help. Many of the old rules don’t apply anymore.

The 2010 engines are likely to be even hotter, get ready.

Root Cause Failure Analysis

Root Cause Failure Analysis

Diesel fuel has been identified by at least one OEM as a Root Cause of Engine Fuel System (pump and injector), EGR, EGR Cooler, Sensor, and Turbocharger failures.

Ford Motor Company recently issued a new TSB (Technical Service Bulletin) regarding vehicles using the 6.0 Liter PowerStroke engine.

TSB 08-2-7 stating that “Some vehicles with a 6.0L diesel engine may exhibit white smoke, black smoke, lack of power, exhaust odor, surges, or no start as a result of excessive coking deposits (un-combusted or incompletely combusted hydrocarbons). The root cause of the coking must be corrected or the coking may reoccur”.

They further state: “Coking deposits are generally un-combusted or incompletely combusted hydrocarbons and can form on system components such as the EGR Valve, EGR Cooler, EBP Sensor, EBP Tube, Intake Manifold, Turbo Charger, Catalytic Converter, and EGR Throttle Plate”.

“Un-combusted deposits can be linked to delayed combustion events. Delayed combustion events can be a function of hard to ignite elements (poor quality fuel, excessive fuel, engine oil, or excessive exhaust gas recirculation) in the combustion chamber or a delayed injection event (calibration, wire chafe, injector mechanical issue (Sticktion)).

“Un-combusted fuel is usually evident as a fuel scented white exhaust smoke. Un-combusted fuel may create coking which impairs system functionality eventually leading to black exhaust smoke/poorly combusted fuel”.

In situations where injectors have built up carbon deposits to the point of not being able to properly atomize the fuel, or EGR Valves that have coked or “carboned” up to the point of no longer being able to regulate the Exhaust gas Recirculation, or EGR Coolers that have plugged, to Turbochargers coked to the point of no longer being able to vary their geometry; common practice has been to replace very expensive parts.

Later some companies developed systems to “flush” the EGR’s and Coolers. Flushing will temporarily improve the operation of the engine, however this type of repair lasts only a short time and the initial problems usually reoccurs.

Oftentimes the same parts are replaced many times and then you have the problem where the one part that is not functioning correctly causes other related parts to fail.
In these instances it is vitally important to determine the root cause of these failures. There is a suggested method to do this:

1. 
   Define the problem.
2. 
   Gather data/evidence.
3. 
   Ask why and identify the causal relationships associated with the defined problem.
4. 
   Identify which causes if removed or changed will prevent recurrence.
5. 
   Identify effective solutions that prevent recurrence, are within your control, meet your goals and objectives and do not cause other problems.
6. Implement the recommendations.
7. 
   Observe the recommended solutions to ensure effectiveness.

Today the Root Cause of 80% to 85% of the diesel engine fuel system related problems is poor fuel quality and fuel characteristics.

In the case of the problems described above on the Ford 6.0L and most of the fuel system and related problems found with other diesel engines, the Root Cause of the Failure is poor fuel quality.

You can replace parts and flush till the cows come home and you will continue to have the same problems over and over and over again.

Note: Albert Einstein once described insanity as: “Doing the same thing over and over again and expecting different results”.

Ford has recommended the use of a Cetane Booster and Performance Improver to improve fuel quality and reduce coking and un-combusted fuel problems.

This is not a Ford only or PowerStroke only problem. Every engine manufacturer has to deal with these problems in one form or another.