What to Do During Diesel Exhaust Fluid Troubles

March 22, 2017 - By 
def fluid

If you have a diesel vehicle, then it’s possible that you may run into DEF problems in the future.

Protect and prepare yourself by reading the guide below on DEF fluid troubles. From explaining the DEF mechanism to troubleshooting the most common problems, we can help you prevent any future problems that you may incur.

Diesel Exhaust Fluid Troubles

Use this guide to manage and treat diesel exhaust fluid troubles.

What is DEF?

Diesel Exhaust Fluid (DEF) is a solution made up of 32.5% urea and 67.5% de-ionized water that is added to a tank separate from the diesel fuel tank.

It is added to diesel vehicles to help them break down harmful emissions into nitrogen and water, through a Selective Catalytic Reduction system.

Due to EPA regulations, vehicle manufacturers have had DEF measurements in place for diesel vehicles since 2010, to help protect the environment and achieve fuel savings for drivers.

When to Add DEF

Make sure you pay attention to the alerts that arise on your dashboard. If a low DEF warning appears, make sure you add fluid as soon as possible.

When the DEF level drops below 10%, an amber warning will appear. At 5%, it will start flashing. If it falls below 2.5%, the engine power will be reduced and the vehicle speed will be stuck at 5 mph until you refill the DEF tank.

To prevent that mess, make sure you fulfill preventative care of your DEF tank and fill up as needed.

Common Mistakes & How to Fix Them

Of course, mistakes can occur when you’re taking care of a vehicle. Educate yourself and make sure you stay on top of preventing mistakes to help you survive future problems.

The top 3 DEF troubles arise from:

1. Putting DEF into Your Diesel Tank

Since DEF is made up of urea and water, putting it into your diesel tank can cause serious problems. That liquid combination can cause engine problems like causing fuel injector tips to explode or cause immediate cooling.

If you made this mistake, follow this protocol:

  • Shut off the engine and contact your engine service provider.
  • Drain the diesel tank and dispose of the fuel.
  • Drain the diesel fuel conditioning module.
  • Flush the fuel system.
  • Replace all filters.

2. Ignoring the Warning Signals for DEF

Again, if you ignored the warning signals for DEF that meant it was time for you add fluid, you will be in trouble.

Warnings traject from Exhaust Fluid Range to Exhaust Fluid Low-Speed-Limited Soon to Exhaust Fluid Empty-Refill Now. Each warning is important as it denotes when it is time to refill.

If you missed these warnings, your car will be limited to 5 mph so make sure you fill up immediately.

3. Putting Contaminated DEF into the System

Contaminated DEF can also create problems, most likely resulting from improper storage.

Symptoms of fuel contamination include:

  • an engine cranking, but won’t start
  • engine runs rough
  • low power
  • engine knocking
  • exhaust smoke
  • FRP slow to build

Contaminated DEF can cause severe damage to the fuel system, so the most recommended repair is to replace the entire fuel system, which can be a very expensive.

Posted In:  Automotive