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
.