are formed in internal combustion engines, the formation of nitrogen oxides (NOx) during fuel combustion. NOx reacts with water in the crankcase to form nitrous acid (HNO₂), which can degrade the oil and increase oil viscosity, Nitration is a particular problem in gas engines due to relatively high combustion chamber temperatures.

Nitration products are formed during the fuel combustion process when combustion by-products enter the engine oil during normal operation or as a result of abnormal “blow-by” past the compression rings.  These products are highly acids, create deposits, and accelerate oil oxidation.  Infrared analysis represents the only method of accurately measuring nitration products in used oil. Results are reported on a absorbance scale.

 Nitration CAUSE

• Improper scavenge
• Low operating temperature
• Defective seals
• Improper air/fuel ratio
• Abnormal blow-by

 Nitration EFFECT

• Accelerated oxidation
• Nitrous oxides introduced into environment
• Acidic by-products formed
• Increased cylinder and valve area wear
• Oil thickening
• Combustion area deposits
• Increased TAN

 Nitration SOLUTION

• Increase operating temperature
• Check crankcase venting hoses and valves
•  Ensure proper air/fuel mixture

Perform compression check or cylinder leak-down test