Alarm Limits for On/Off Highway Engines

Introduction

Engine design has rapidly advanced in the last decade, and that, combined with innovative uses of metals and ceramic components, has led to very low wear, and extended oil drain intervals. Engine manufacturers have recognized the advantages of oil analysis, and now produce bulletins on an annual basis which summarize oil analysis alarms. They are also very helpful for engine component metallurgy knowledge. These bulletins may be had by calling your local engine distributor, or by contacting the oil analysis laboratory. Many engines use a multigrade oil, designed to provide protection over the wide thermal variations that this equipment sees. These lubricants contain the most advanced lubricant additive packages available, and both these packs and the viscosity are highly regulated by such authorities as the API and SAE. The following table summarizes condemnation limits from three popular engines manufacturers.

Engine Manufacturer
Oil Analysis Test	Caterpillar (all models)	Cummins (all models)	Detroit Diesel (all models)
Spectroscopy, Iron	100 ppm	84 ppm	150 ppm
Spectroscopy, Copper	45 ppm	20 ppm	90 ppm
Spectroscopy, Lead	100 ppm	100 ppm	none specified
Spectroscopy, Aluminium	15 ppm	15 ppm	none specified
Spectroscopy, Chromium	15 ppm	15 ppm	none specified
Spectroscopy, Tin	20 ppm	20 ppm	none specified
Spectroscopy, Sodium	40 ppm	20 ppm	50 ppm
Spectroscopy, Boron	20 ppm	25 ppm	20 ppm
Spectroscopy, Silicon	10 ppm	15 ppm	none specified
Viscosity	+20 % to -10 % of nominal SAE grade	+/- 1 SAE grade or 4 Cst from new oil (Visc @ 100 ° C)	+40 % to -15% of nominal grade (Visc @ 40 ° C)
Water	0.25% max	0.2% max.	0.3% max
TBN	1.0 mg KOH/g min value	2.0 mg KOH/g min., or one-half of new oil value, or equal to TAN	1.0 mg KOH/g min value
Fuel Dilution	5% max.	5% max	2.5% max
Glycol Dilution	0.1% max	0.1% max	0.1% max.
Ferrography	on exceptions	on exceptions	on exceptions

Notes:

1. These values represent all models of engine for the manufacturers listed and serve as a guide only. Consult your distributor for specific requirements.

It is worth noting the condemnation limit variation by manufacturer in the above table. It proves that different companies use different criteria for normal operation. Use of these limits, combined with statistical trending, will catch any abnormalities that may arise.