By Dave Scott
The humble engine oil dipstick plays a crucial role in determining correct lubricant levels – especially in older trucks without electronic sump-level sensors and instrument panel signals.
Drivers’ daily checks include engine oil levels, but, unless the check is specific and limited to the engine only with training on how and when to read the dipstick, there is a danger that an ‘enthusiastic’ driver starts checking all the other dipstick levels that are best left to workshop technicians. Power steering, torque convertor automatic transmissions, and automated manual transmission (AMT) viscous couplings all require top-up techniques at operating temperatures with absolute cleanliness. Some systems – such as automatic gearboxes – require the lubricant level inspection while the engine is idling.
Checking procedures are often executed pre-dawn in poor light, making reading an engine dipstick a hit-and-miss procedure. Many drivers mistakenly err on the side of overfilling.
The problem is compounded with re-inserting the dipstick in the dark and missing the seating orifice – the bottom of the dipstick gets jammed into dirt around the dipstick entry point. The accumulated contamination is then inserted into the engine to initiate engine wear and premature failure – a disaster!
Engine lube levels must be checked when a vehicle is on a level surface.
Dipstick procedures must be cold checks
Top-up oils are mostly stored at the fuel pump, meaning vehicles drive there before checking the dipstick. Oil levels should be checked before engine start-up. When the vehicle arrives for refuelling, the engine is warm, with oil in the cylinder head and other galleys, giving a false dipstick reading.
Disaster warning – an increasing engine oil dipstick level
Drivers are untrained to track the severe warning signal of an increased dipstick level. Swift action must be taken to determine the root cause of elevated levels.
Drivers must be trained to read dipstick levels – halfway between the bottom and top marker on the dipstick is perfectly acceptable. What is unacceptable is several half-full containers lying around waiting to top up half-full engine sumps.
Distance is not a yardstick
A truck diesel engine will consume oil, but in relation to how hard the engine works and fuel consumption – not the distance the wheels have rolled. Variance in dipstick readings is relevant to fuel consumption and not distance. The most accurate ratio is a percentage of fuel consumption – a general figure across the board is around 0,6% of total fuel consumption. Exceeding a 1% benchmark on a truck means there’s something mechanically seriously wrong, or, either negligent dipstick-level reading, or fraudulent ‘skimming’ is occurring.
Conclusion – measure to manage
Measuring against an oil consumption database that tracks top-up lube used against individual vehicles provides a running cumulative fleet total. Here are some guidelines:
- Draft a lubrication policy in which top-up features, with its own standard operating procedures (SOPs).
- Arrive at individual and total fleet ratios of top-up to fuel consumed.
- Establish benchmark averages and trends – start with a ratio of 0,6% and manage by exception. Exceeding 1% needs serious investigation.
- Write dipstick management into a job description.
- Clean up all lube equipment.
- Make everyone aware of the environmental impact of dipstick and top-up control.
- Get lubrication reports into the monthly management operation accounts
Checking engine lubricant consumption is monitoring engine life – it starts at the dipstick What appears to be a simple, menial task is important, requires training and understanding, and must be executed in absolute cleanliness. Every day, millions of vehicles undergo engine lubricant checks, revealing much wastage, magnified by ignorance, and fraud, with a negative environmental impact. Let’s clean up!
The full WearCheck article can be downloaded here https://www.wearcheck.co.za/shared/TB80.pdf
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