Using simple science you can easily extend lubricating oil life, plus significantly extend engine and component life.
Scientific oil analysis, preferably on a regular basis rather than a “one off”, allows you to take preventative maintenance measures well ahead of expensive repairs becoming necessary.
Regular oil analysis can save the life of your engine, transmission, or other components of machinery.
All lubricating oils change both physically and chemically during their service life.
Over time the following things can happen to lubricating oil:
- Accumulation of wear debris, in the form of various metals from lubricated components.
- Entry of external contaminants such as dust, water, coolant and even unburnt fuel.
- Build up of combustion bi-products, especially acids and carbon.
- Deterioration due to heat and physical sheer effects.
In the broadest sense, scientific analysis of used lubricating oil can tell you three things:
1. Is the oil condition OK for further use? Oil viscosity should still be within a satisfactory range. Contaminant levels should not be excessive. Oil additive packages, especially the acid buffering Total Base Number (TBN), should not be excessively depleted.
2. Are operating conditions normal? Entry of dust, coolant, fuel, soot, sulphur and high oxidation levels reflect a problem that if left unattended, will shorten the service life of the oil, but perhaps more importantly shorten the life of lubricated components.
3. Is excessive wear taking place? All wear metals are measured in parts per million (ppm). Where levels exceed a normal upper limit, wear is designated as abnormally high. These levels do vary with engine type. Some manufacturers can extrapolate the economic life of a diesel engine by plotting the wear rates from a series of oil samples.
By regular oil analysis monitoring, you’ll find that it is possible to set new standards (lower) for wear rates by using higher quality lubricants, anti-friction oil additives, combustion chemistry fuel additives, better air and oil filtration and even the latest in extending engine life, restorative ceramic metal nanotechnology.
How can oil analysis save the life of your engine?
Suppose your 4×4 does a lot of dusty outback work. Your next oil analysis alerts you to high silicone. Silicone is the major element in dust and points to a faulty air induction system. Quite likely, this will be accompanied with elevated iron (from cylinder liners), chromium (from piston rings), and lead (from bearings). If you correct the problem early, a catastrophic engine problem is avoided, so you would look for a poorly fitting air filter, or leak (pin hole) and any loose hose connection from your air cleaner to your inlet manifold.
A routine laboratory engine oil analysis on my Range Rover diesel engine identified elevated sodium, indicating coolant entry. The level was not large, but elevated and I was not losing excessive coolant. I re-tensioned the cylinder head and sent another sample for analysis on the next oil change. The problem was solved, well ahead of any damage to the engine, or even visible signs of water in the oil.
A very common problem with small pre-combustion diesels (especially Japanese) is high soot, derived from combustion. The oil change interval is generally recommended at 5000km, however, depending on operating conditions and quality of service, they may be well and truly be overloaded with soot by 5000km. Factors which can exacerbate this include engine sludge being re-suspended at the oil change. In severe cases, this can overload the fresh oil instantly!
Other problems, which can cause excessive soot include:
- Over-fuelling (fuel pump setting too high)
- Excessive idling
- Dribbling or sticking injectors
- Incorrect fuel injection timing
- Restricted air filter or air intake system
- Cool operation (eg stop-start, or sticking thermostat)
High sodium usually indicates a coolant leak, as sodium is a common element in cooling system inhibitors. High lead can indicate bearing wear. High aluminum can be from pistons.
The higher the wear metal value, the more severe the wear.
It sounds simple enough, but the interpretation of oil analysis results can be complicated by many factors, including:
- The sample taken should be representative.
- The oil should be hot and well mixed, and sampled cleanly.
- The oil service life must be taken into consideration, low contaminants at low oil hours/kms can mean things aren’t as good as it might seem.
- The amount of oil top up must be considered, since topping up dilutes the contaminants.
Development of trends over a series of oil samples, rather than a “one off” provides a much better idea of how an engine is performing.
Harmful oil contaminants, where they likely come from and what you can do about them.
Dirt .. External, enters past air filter or seals. Locate and repair fault
Coolant .. Cooling system leak, due to corrosion, faulty gasket, or cracks. Oil will disperse and control small amounts. Locate and repair the fault.
Water .. Cooling system leak (as above), condensation, combustion. Oil disperses small amounts. Minor water entry is removed by evaporation. Locate and repair fault. Change oil & filter. Flush system if severe problem.
Soot .. Poor combustion of diesel fuel. Oil disperses soot until additive package is exhausted (then sludge is produced). Check for over-fueling, injection timing wear (retarded), restricted air inlet, turbocharger, injectors sticking or worn, fuel quality. Change oil and filter. Flush if severe. Use FTC catalyst in the fuel and flush oil with DeSLUDGE.
Oxidation products .. High temperature operation, high temperature at lubricated points, other contaminants can accelerate oxidation. Oil disperses some contaminants. Go to a higher quality oil with more stable base oil stocks and anti-oxidant. Use of anti-wear will reduce high point temperatures .. SupaSLIP
Fuel .. Over-fueling, dribbling injectors, leaking fuel line, worn cylinder liners, sticking piston rings. Oil disperses, but loses viscosity rapidly, increasing wear. Change oil more frequently until fault repaired. Use high quality flushing oil concentrate to free sticking piston rings. DeSLUDGE.
Sludge .. Formed by soot, water, oil residues and dirt. Insoluble in oil. Use quality flushing oil concentrate to re-suspend and remove sludge. Go to higher quality oil. Check as per soot. Use FTC catalyst in the fuel and flush oil with DeSLUDGE.
Gum, varnish & lacquer .. Fuel, fuel + oil and baked varnish respectively. Use high quality crankcase oil. FTC catalyst decarbonizer will burn off from combustion spaces, where a glaze is formed.
Ash .. Fuel and additive packages from crankcase oil. Control fuel quality. Additional finer filtration of fuel may be necessary. Reduce oil burning. Use of FTC catalyst decarbonizer will burn the carbon from the deposits, that is the binder for the ash, allowing it to deplete.
Carbon .. Fuel & oil Check as for soot. A detergent/dispersant type fuel additive with upper cylinder lubricant is recommended to deplete inlet port deposits for carburetor and port fuel injection systems, and to correct fuel spray patterns CP. FTC catalyst decarbonizer should be used to burn off carbon from cylinder heads, piston crowns, top lands and top ring grooves, turbochargers, exhaust manifolds, etc.