One of the most commonly asked questions we get is regarding
the necessity of SCA (Supplemental Coolant Additive). It
is vital for the health and longevity of any diesel engine.
Diesels, particularly the Ford Powerstroke, are prone to a
problem called Cavitation (or liner pitting).
DCA4 is recommended for Ford Powerstroke, International
Truck, and Cummins engines. For GM Duramax, Caterpillar,
and Detroit Diesels, DCA2 is the required SCA.
Note: DCA4 is equivalent to Ford FW-16 (or new name VC-8)
The pistons in your engine move up and down about 2,000 times a
minute. While they move vertically, the crankshaft is performing
a completely different movement by rotating horizontally. These
contradictory movements will cause your engine’s liners to
vibrate a lot. Although the outer wall of the liner is
surrounded by cooling fluid, its inertia creates tiny vacuum
pockets, causing bubbles of vapor to form on the liner wall.
When the liner vibrates back, these bubbles collapse under an
enormous pressure of about 1,000 bar, and take small chunks out
of the liner. Eventually you will have block failure.
To prevent this, a supplemental coolant additive needs to be
added to the cooling system. To check the SCA level you
should periodically test your coolant using
Fleetguard 3-Way test strips.
What is the
proper chemical SCA
concentration for diesel engines? Basically a chemical
concentration of 1.5 - 3.0 UPG (Units Per Gallon) should be
maintained in your cooling system at all times. How do you
achieve that? Well, this depends on the capacity of the coolant
system. For a reference, a 1 pint bottle of DCA4 additive is equal to 5
We recommend that you add up to 2.5 UPG if you don't test the
SCA as often as you should. Keeping the level this high
will help ensure that the level is at least 1.5 UPG.
Ideally you should test the SCA every 4-6 months. If you
do, then you can keep the level at a lower level of 2.0 UPG.
The benefit of a lower level will help prevent the buildup of
particles that SCAs often cause. This buildup can become
loose or flake off the water jacket walls, and because it can be
abrasive, it will cause damage to your water pump or even clog
certain parts of the cooling system like the heater core. A
preventative measure that can be taken to eliminate this is the
use of a coolant filter.
Example of achieving the proper SCA level.
A 2001 Ford Powerstroke 7.3L has a capacity of 32.75 quarts or
8.2 gallons. To figure out how many units 1 pint of additive
will raise the coolant level, divide the 5 units (the amount
that 1 pint will give you) by the capacity
in gallons (8.2). So 5 divided by 8.2 = 0.61, so this tells you that
each pint of additive will raise the coolant level to 0.6.
So if your current level is now at 1.3 units of SCA (as tested
with the test strips) and you wish to reach a level of 2.5 you
would need to add 2 pints (2pts x 0.6 = 1.2, 1.2 + 1.3 = 2.5)