Water in oil

Is Water Wrecking Your Engine?

Water contamination in automotive oil is a serious issue that can lead to severe engine damage if left unchecked. Whether you own a passenger car, a commercial vehicle, or manage a fleet, understanding the impact of water ingress in engine oil is critical for maintaining performance, reliability, and longevity.

In this blog, we explore the causes, signs, and symptoms of water contamination, as well as how to address and prevent the problem.

How Does Water Enter the Oil?

Water can enter the engine oil system through several pathways:

  • Condensation: When engines cool down after operation, condensation can form inside the engine, particularly if the vehicle is used for short trips where the engine does not reach full operating temperature.
  • Coolant Leaks: A blown head gasket, cracked engine block, or a faulty oil cooler can allow coolant to mix with oil.
  • Environmental Exposure: In some cases, particularly in off-road or heavy-duty environments, water can enter through poor seals or during deep-water wading.

Regardless of the entry point, water in oil reduces lubrication effectiveness and can cause serious internal damage if not promptly addressed.

Signs and Symptoms of Water in Oil

Early detection is crucial. Here are some common signs that water may have contaminated your oil:

  1. Milky or Frothy Oil: One of the most obvious indicators is a milky, frothy, or creamy appearance in the oil. Water mixing with oil creates an emulsion that looks like a light-coloured sludge, often found on the underside of the oil filler cap or the dipstick.
  2. Elevated Oil Level: If you notice the oil level rising without having topped it up, it could indicate that coolant or water is leaking into the oil system.
  3. Engine Overheating: Contaminated oil loses its ability to lubricate and cool engine components effectively, leading to overheating.
  4. Poor Engine Performance: A rough idle, misfiring, or reduced power could be symptoms of internal issues caused by poor lubrication and corrosion.
  5. Unusual Exhaust Smoke: White, sweet-smelling exhaust smoke can indicate coolant entering the combustion chamber — a strong sign of head gasket failure that may also mean water has entered the oil system.
  6. Rust or Corrosion: Internal engine components may develop rust or corrosion if water remains present, leading to increased wear and potential failure.

The Consequences of Ignoring Water Contamination

Ignoring water contamination can be catastrophic. Water reduces the oil’s film strength and viscosity, leading to metal-on-metal contact. Over time, this can cause:

  • Severe bearing damage
  • Camshaft and crankshaft wear
  • Corroded internals
  • Engine seizure

In commercial applications, such failures can result in costly downtime and major repair bills.

How to Confirm Water Contamination

Laboratory oil analysis is the most accurate method for detecting water contamination. Regular oil sampling and analysis can detect water at low levels before visible signs appear, allowing corrective action to be taken early.

Simple in-house tests, such as the “crackle test” (heating a small amount of oil on a hot plate to see if it crackles), can indicate the presence of water, but professional analysis is strongly recommended for a definitive assessment.

Solutions and Prevention

If water contamination is suspected:

  • Stop operating the engine immediately to prevent further damage.
  • Drain and replace the oil and filter.
  • Identify and repair the source of the water ingress.
  • Flush the engine if necessary to remove residual contamination.

To prevent water contamination:

  • Ensure regular servicing and inspections.
  • Monitor coolant levels carefully.
  • Use quality gaskets and seals.
  • Avoid deep-water driving without appropriate vehicle modifications.
  • Conduct regular oil analysis for early warning signs.

Conclusion

Water contamination in automotive oil is a hidden enemy that can lead to devastating engine damage if left untreated. By recognising the symptoms early and taking swift action, you can protect your engine, extend its service life, and avoid costly repairs. Regular maintenance, vigilance, and oil analysis are your best defences against this often-overlooked threat.

If you suspect water in your oil or wish to implement a proactive oil analysis programme, contact your trusted oil analysis provider for expert advice and support.

air tool lube

Air Tool Lubrication

The Secret to Smooth-Running Pneumatic Tools

Air tools, also known as pneumatic tools, are a class of power tools driven by compressed air supplied by an air compressor. These versatile tools come in a wide variety of shapes and sizes — from small hand-held devices to jackhammers (paving breakers) and large, rig-mounted equipment used in mining and quarrying.

In the tooling industry, general-grade air tools are relatively inexpensive, have shorter lifespans, and are often viewed as “disposable.” In contrast, industrial-grade pneumatic tools are among the toughest and most durable power tools available. Yet, even these can experience premature failure. To understand why, it’s important to first consider how pneumatic tools operate.

How Pneumatic Tools Work
An air compressor forms the heart of any pneumatic system, converting ordinary air into compressed air. This compressed air travels through a flexible hose to the actuator at the business end of the system. The actuator then converts this potential energy back into kinetic energy, producing useful mechanical work.

Actuators either move back and forth (reciprocating action) or rotate. For example:
• Percussion tools like jackhammers use piston-type actuators.
• Rotary tools such as air drills and grinders use geared or turbine motors.

What Causes Air Tool Failure?
Despite their rugged construction, many pneumatic tools fail before their time due to poor maintenance and operating conditions. The two primary culprits are dirty air and moisture:
• Contaminants like grinding dust can infiltrate the actuator and cause abrasive wear.
• Moisture promotes rust within the tool, especially if wet air is introduced into the system.
To combat this, it’s crucial to fit an airline filter and water trap between the compressor and the tool. This removes impurities and most of the moisture from the air supply — although achieving completely dry air isn’t always practical.

The Role of Lubrication
Just like engines, the moving parts inside pneumatic tools require consistent lubrication to prevent wear and ensure smooth operation. However, air tools lack a built-in oil sump, so lubrication must be delivered via the compressed air.

This is where airline lubricators come in. These devices inject a fine oil mist into the airstream, lubricating valves, cylinders, and motors, helping the tool operate efficiently and extending its service life.

Correct positioning of the lubricator is important, as is the oil quantity:
• Too little oil leads to excessive wear and early failure.
• Too much oil is wasteful and can contaminate the workspace, carried out with the tool’s exhaust air.

How Airline Lubricators Work
A typical airline lubricator features an oil reservoir that feeds lubricant into the moving airstream. As compressed air flows through a venturi inside the lubricator, it draws oil from the reservoir through a capillary tube, dispersing it as a fine mist into the air supply.

The system includes:
• An adjusting valve to control the oil flow rate.
• A sight glass for monitoring output.
• A filler plug for convenient in-place refilling.

Lubricators are usually specified based on pipe connection size, oil reservoir capacity, acceptable pressure drop, and flow rate. Most manufacturers also recommend a minimum air flow rate for the lubricator to function correctly.

Challenges in Pneumatic Tool Lubrication
Pneumatic tools are precision-built with close-tolerance components, often operating under demanding conditions. During use, internal temperatures can vary dramatically, especially in reciprocating tools. The combination of heat, high loads, and moisture makes adequate lubrication absolutely essential.

Lubricants for air tools must:
• Control wear.
• Protect against rust and corrosion.
• Resist foaming and water wash-off.
• Prevent sludge and deposit formation.
• Minimise fogging (especially important in mines and enclosed areas).

Protecting Seals and ‘O’ Rings
The most vulnerable parts of pneumatic tools are the internal rubber seals, typically ‘O’ rings. While lubrication is vital, the wrong type of oil can degrade these seals. It’s therefore essential to use a lubricant specifically formulated for pneumatic tools, typically blended with:
• Highly refined mineral oils.
• Anti-wear and tackiness agents.
• Emulsifiers, rust inhibitors, anti-foam and anti-fogging additives.

Selecting the Right Oil Viscosity
The oil viscosity affects how much lubricant is picked up by the airline lubricator — and this varies with temperature. Equipment manufacturers’ recommendations should always be followed, but in their absence, the following ambient temperature guidelines can help:

• Small hand-held tools: ISO VG 32
• Larger industrial tools:
o ISO VG 100 (below 20˚C)
o ISO VG 150 (20˚C to 25˚C)
o ISO VG 220 (25˚C to 30˚C)
o ISO VG 320 (30˚C to 35˚C)
o ISO VG 460 (above 35˚C)

When operator health and safety is a priority — such as in underground mines — greases or emulsions are often a preferred alternative for large tools like rock drills.

Conclusion
Pneumatic tools are designed for tough environments, but they rely on proper lubrication to perform well and last long. A well-maintained lubrication system, using the correct oil type and viscosity, not only protects your investment but also ensures a safer, cleaner, and more efficient working environment.

Blue Chip Lubricants (Pty) Ltd offers a full range of air tool lubricants for diverse operating conditions. To find out more, contact us at info@bcl.co.za — we’d be happy to assist.

Oil filter clogging

The Impact of a Clogged Oil Filter: Signs, Symptoms, and Why It Matters

When it comes to maintaining your vehicle’s engine health, few components play as vital a role as the oil filter. Often overlooked during routine maintenance, the oil filter is responsible for trapping dirt, metal particles, and other contaminants from the engine oil. Over time, however, the filter can become clogged — and the consequences can be far more serious than many motorists realise.

What Does an Oil Filter Do?

Before we look at the symptoms of a clogged filter, it’s worth understanding its job. Engine oil circulates throughout the engine to lubricate moving parts, reduce friction, and carry away heat. As it flows, it can pick up particles of dirt and debris. The oil filter’s job is to remove these impurities, preventing them from causing wear or damage inside the engine.

The Impact of a Clogged Oil Filter

  • When an oil filter becomes clogged, it can no longer effectively clean the engine oil. This causes several potential problems:
  • Restricted oil flow: The engine may not receive sufficient oil, leading to increased friction and overheating.
  • Contaminated oil circulation: Dirty oil continues to circulate, accelerating engine wear.
  • Bypass valve activation: Most oil filters are fitted with a bypass valve, which allows unfiltered oil to flow through if the filter is too clogged — better than no oil at all, but still risky for the engine.

Left unchecked, these issues can cause long-term engine damage, reduced efficiency, and, in the worst cases, complete engine failure.

Signs and Symptoms of a Clogged Oil Filter

Knowing what to look out for can help you act before serious damage occurs. Common signs include:

  • Oil Pressure Warning Light: A clogged filter can cause a drop in oil pressure, triggering the dashboard warning light.
  • Unusual Engine Noises: Ticking, metallic knocks, or increased engine noise may result from poor lubrication.
  • Dirty Exhaust Smoke: Excessively dark or dirty smoke may indicate that contaminated oil is circulating.
  • Overheating: Insufficient lubrication can cause the engine to run hotter than usual.
  • Drop in Engine Performance: Poor oil flow can lead to sluggish acceleration or reduced power.

Conclusion

While it might be a relatively small and inexpensive component, the oil filter plays a crucial role in engine health. A clogged oil filter can restrict oil flow, allow contaminants to circulate, and increase the risk of significant engine damage. Recognising the warning signs early — and ensuring regular oil and filter changes — is one of the simplest yet most effective ways to protect your vehicle and keep it running smoothly.

So next time you’re due for a service, don’t underestimate the humble oil filter. It could save you from a costly repair bill and extend the life of your engine for many miles to come.

Chain lubrication

Keeping the Links Alive: The Art of Proper Chain Lubrication

Chains are everywhere. From bicycle gears to forklift mechanisms, and from conveyor belts to the unmistakable whirr of a chainsaw — chains quietly keep industries and daily life in motion. Yet, despite their ubiquity, chains are often one of the most neglected components when it comes to maintenance. One of the main culprits? Poor lubrication.

Why Chains Fail – And It’s Not What You Think
Most people associate chain lubrication with slathering on heavy oil or grease. While that may protect the outer surfaces and sprockets, it does very little for the chain’s most vulnerable parts — the internal surfaces. In fact, over-lubrication with the wrong product can attract dust and sand, creating a grinding paste that rapidly accelerates wear.

Here’s the harsh truth: the majority of chains fail from the inside out.

They stretch, kink, or seize because of wear and corrosion inside the pin and bushing areas. And once that internal integrity is compromised, no amount of external oiling will save them.

Lubrication That Works: It’s What’s Inside That Counts

For effective lubrication, the oil needs to:
• Penetrate into the critical internal contact points
• Leave behind a protective film that withstands pressure and temperature
• Provide rust and corrosion protection
• Resist being flung off during operation

In essence, you want a lubricant that’s smart enough to reach deep, strong enough to stay in place, and tough enough to perform in harsh conditions.

This is where specially formulated chain lubricants come in. They typically use high-viscosity index base oils that flow easily at low temperatures (to penetrate inside the chain), while still holding strong under high loads and heat. Additives like anti-wear agents, extreme pressure enhancers, rust inhibitors, tackiness agents, and more ensure the lubricant performs across a wide range of applications.

For chains used in food production, food-grade chain lubricants are a must — offering all the protective qualities without compromising safety

Suggested viscosity grades for various ambient temperature ranges are shown in the following table:

Application is Everything
Even the best lubricant in the world won’t do its job if applied incorrectly. The key is targeting the pin and bushing area — the heart of the chain’s movement.

Whether you’re using manual application, a drip feed, oil bath, brush, or an automated system, the timing and placement of the lubricant is crucial. Apply it just before the chain engages with the sprocket. As it wraps around the sprocket, centrifugal force draws the lubricant into the tight internal clearances — exactly where it’s needed most.

Lubricant spillage over the inner link plates also helps coat the rollers and their end surfaces. However, using grease (especially thick types) on chains in service is not recommended unless the chain is specifically designed with grease fittings that can inject lubricant into the joints.

Chain Care: A Matter of Detail
To get the most from your chains, you need to consider all operating conditions — load, speed, temperature, environment — and select a lubricant that’s tailored to that context.

At Blue Chip Lubricants, we understand that not all chains are created equal, and neither are their lubrication needs. With the right combination of expertise, products, and service, we help keep the chains of industry turning smoothly and efficiently.

Got a chain problem or unsure which lubricant to choose? Drop us a line at info@bcl.co.za — we’re ready to help you link up with the best solution.

Overheating

Can Low Oil Cause Your Engine to Overheat? Absolutely — Here’s Why.
When we think of engine overheating, we often blame low coolant or a faulty radiator. But low oil can be just as dangerous—and just as responsible for sending your temperature gauge soaring.

Why Oil Matters for Cooling
Engine oil isn’t just for lubrication. It plays a major role in temperature regulation by:
• Reducing friction between moving parts
• Absorbing and dispersing heat
• Flowing through the engine to prevent hot spots

Some engines even have oil coolers to help with this process.

What Happens When Oil Is Low?
When oil levels drop, things heat up:
• Increased friction creates excess heat
• Oil can overheat and break down, losing effectiveness
• Poor lubrication leads to hot spots and possible engine damage
• Over time, this strain can cause complete engine failure

Warning Signs to Watch For
• Rising engine temperature
• Burning oil smell
• Ticking or knocking noises
• Oil pressure warning light

Prevention Tips
• Check oil levels regularly
• Stick to recommended oil change intervals
• Fix oil leaks as soon as possible

Low oil might not boil your coolant, but it will cook your engine from the inside out. Keep an eye on that dipstick—it could save you thousands.

Base oils

Understanding Synthetic Base Oils: A Closer Look
Base oils form the foundation of all lubricants, making them a critical component in ensuring optimal performance across various applications. Given the number of new visitors to our website and the increasing enquiries we receive regarding base oils, we felt it appropriate to revisit this topic—particularly synthetic base oils.

API Classification of Base Oils

The American Petroleum Institute (API) classifies hydrocarbon-based oils into five distinct groups, based on refining methods and key properties such as viscosity index (VI), saturates, and sulphur content.

Group I: Conventional Mineral Oils

Group I base oils are the least refined and are produced through solvent refining—a process that removes undesirable compounds and impurities. These oils typically have a viscosity index of around 100 and are straw to light brown in colour. Although still in use, they are being increasingly replaced by higher-quality alternatives.

Group II: Highly Refined Mineral Oils

Group II base oils undergo hydrocracking, a process that removes most unstable aromatic hydrocarbons and sulphur. As a result, these oils are clearer, more stable, and have improved performance characteristics. They typically feature a viscosity index of around 110, with some high-quality versions exceeding 115. Due to their enhanced properties and competitive pricing, they are widely used in modern lubricants.

Group III: The Highest Quality Mineral Oils

Group III base oils are refined through hydrocracking, hydroisomerisation, and hydrotreating, making them significantly purer than Group I and II. They boast a viscosity index greater than 120 and, while derived from mineral sources, their characteristics closely resemble those of synthetic Group IV oils.

Group IV: True Synthetic Base Oils (PAOs)

Group IV oils consist of chemically engineered synthetic hydrocarbons known as polyalphaolefins (PAOs). These oils contain no unsaturated hydrocarbons, sulphur, nitrogen components, or waxes, making them highly stable with a viscosity index typically above 130. PAOs offer superior high- and low-temperature performance, excellent oxidation stability, and compatibility with mineral oils, making them the most common synthetic base oils in automotive and industrial lubricants.

Group V: Speciality Base Oils

Any base oil not classified within Groups I–IV falls under Group V. This diverse category includes esters, polyglycols, naphthenes, polybutenes, silicones, and biolubricants. These oils are often blended with others to enhance performance characteristics. For instance, PAO-based compressor oils are frequently combined with polyolesters to improve thermal stability and detergency.

The API categorizes lubricating base oils according to their chemical and physical properties as shown below:

PROPERTY Gr 1 Gr 2Gr 3Gr 4Gr 5
Saturates<90%
and/or
>90%
and
>90%
and
P
A
O
T
Sulphur>0.03%
and
<0.03%
and
<0.03%
and
OH
E
Viscosity Index80 – 12080 – 120>120>125R

The Debate Over Synthetic Lubricants

Rewinding to the late 1990s, a landmark legal battle unfolded in the USA between Mobil and Castrol over the definition of synthetic oils. Mobil contested Castrol’s claim that its Group III oils were synthetic. However, in 1999, Castrol successfully argued that their extensive hydroprocessing modifications qualified Group III oils as synthetic. As a result, the API removed ‘synthetic’ from its classification system, turning it into a marketing term rather than a scientifically measurable category.

Terminology in Today’s Market

Currently, hydrocarbon base oils are typically described as follows:

Mineral Oils: Group I and II oils are referred to as mineral base oils or highly refined base stocks.

Semi-Synthetic Oils: A blend of Group I and/or II oils with Group III and/or IV. These are also labelled as part-synthetic, synthetic-based, or synthetic technology oils.

Synthetic Oils: Following the 1999 ruling, Group III oils are commonly marketed as synthetic.

Full Synthetic Oils: This term is usually reserved for Group IV polyalphaolefin (PAO) base oils.

Group V oils are generally identified by their chemical names, such as polyolester, alkylbenzene, polyalkylene glycol, and polyisobutylene, sometimes prefixed with ‘synthetic’.

Conclusion

Understanding base oils and their classifications is crucial when selecting the right lubricant for your application. With the evolution of refining processes and changing industry definitions, synthetic lubricants continue to be a key area of discussion. If you have any questions about base oils or need assistance in choosing the right lubricant, feel free to reach out to our team—we’re happy to help!

Sludge

Understanding Engine Sludge: Causes, Fixes, and Prevention
Engine sludge is a serious issue that can cause major problems for your vehicle if left unchecked. It affects engine performance, reduces lubrication, and can even lead to costly repairs. In this blog post, we’ll explore what engine sludge is, how it forms, and most importantly, how you can fix and prevent it.

What is Engine Sludge?
Engine sludge is a thick, tar-like deposit that builds up inside an engine due to oil degradation and contamination. It can clog vital oil passages, leading to reduced lubrication, overheating, and even engine failure if not addressed promptly.

How is Engine Sludge Formed?
Several factors contribute to engine sludge formation, including:

  1. Poor Maintenance & Infrequent Oil Changes
    Failing to change engine oil regularly leads to oil breakdown, causing it to turn into a thick sludge.
  2. Short Trips & Stop-and-Go Driving
    Engines need to reach optimal temperature to burn off moisture and contaminants. Frequent short trips prevent this, leading to sludge buildup.
  3. Low-Quality or Incorrect Oil
    Using the wrong type or low-quality oil accelerates degradation and sludge formation.
  4. PCV System Malfunction
    A faulty Positive Crankcase Ventilation (PCV) system can trap moisture and contaminants inside the engine, contributing to sludge.
  5. Overheating
    Excessive heat breaks down engine oil faster, leading to sludge deposits

How to Prevent Engine Sludge
Prevention is key to keeping your engine running smoothly. Follow these tips:
• Regular Oil Changes: Follow manufacturer-recommended intervals and use high-quality synthetic oil.
• Avoid Short Trips: Drive long enough for the engine to reach optimal temperature and burn off moisture.
• Use the Right Oil: Always use the oil recommended for your engine type.
• Maintain the Cooling System: Prevent overheating by ensuring the cooling system functions properly.
• Check the PCV Valve: Regularly inspect and replace the PCV valve if necessary.

Final Thoughts
Engine sludge is preventable with proper maintenance and attention to oil quality. By following these steps, you can extend the life of your engine and avoid costly repairs. Don’t wait until it’s too late – stay proactive and keep your engine sludge-free!


Have you experienced engine sludge issues? Email us at info@bcl.co.za, and we’ll provide tailored solutions to keep your equipment running smoothly.

Aeration and foaming

Foaming and air entrainment in lubricating oil circulation systems are more common than you might think. Left unchecked, they can lead to serious operational issues such as fluctuating oil pressure, oil pump cavitation, excessive oxidation, and even machine breakdowns. Understanding the causes of foaming and how to manage it effectively is crucial for maintaining optimal lubrication and system performance.

Why Does Lubricating Oil Foam?
Most lubricating oils are formulated with antifoam additives to minimize foaming. However, contrary to what their name suggests, foam inhibitors don’t prevent air bubbles (aeration) from forming in circulating oil. Instead, these additives (often silicone-based) reduce the surface tension of air bubbles, causing them to rupture and merge into larger bubbles that rise quickly to the oil’s surface and dissipate, as illustrated below:

Measuring Foam in Lubricating Oil
The foaming tendency and stability of a lubricant are typically tested using the ASTM D892 test method, which consists of three sequences:
• Sequence I: Measures foaming tendency and stability at 24°C.
• Sequence II: Measures foaming tendency and stability at 93.5°C.
• Sequence III: Conducted at 24°C, but on the same fluid that was tested in Sequence II.

The results are reported in a two-number format, e.g., 20/0, where the first number indicates foam tendency (in milliliters) after five minutes of aeration, and the second number represents foam stability after a ten-minute settling time. Ideally, new oils should have a maximum foam tendency of 10 to 50 mL and 0 mL foam stability after the settling period.

This photo of two oils was taken during the five-minute aeration period of the ASTM D892 Foam Test. Excessive foam formation can be seen on the surface of the oil on the left which contained no antifoam additive. The oil on the right was fortified with a foam inhibitor and exhibits negligible foam formation. The photo also shows the larger oil bubbles (that migrate to the surface more readily) in the oil with the antifoam additive.

Although the majority of lubricating oils are formulated with antifoam additives, foam and air entrainment problems are quite common and are usually hard to treat. Traditionally the standard procedure was to run an ASTM D892 foam test on the offending oil, and then indiscriminately add an aftermarket antifoam additive. Generally, foam went away quickly, only to return shortly afterwards. More antifoam was added, and the cycle was repeated until the system became so overloaded with foam inhibitor that the oil had to be dumped. Today, there are more practical methods of establishing and treating the source of foam problems and it is therefore usually unnecessary to use aftermarket antifoam additives.

What Causes Foaming and How to Fix It?
Even though most lubricants contain antifoam additives, persistent foaming issues can still occur. The root causes vary but often include:
✅ Water Contamination: Even small amounts of water in oil can promote foaming. ✅ Solids Contamination: Dirt and debris disrupt oil flow and encourage foam formation. ✅ Depleted Foam Inhibitor: Excessive fine filtration can strip oils of their foam inhibitors. ✅ Mechanical Issues: Leaks, excessive turbulence, and air leaks in pumps can aerate the fluid. ✅ Incorrect Oil Level: Overfilling or underfilling the sump can create foaming problems. ✅ Cross-Contamination: Mixing different lubricants can lead to foaming. ✅ Grease Contamination: Grease entering the oil can alter its foaming properties. ✅ Too Much Antifoam Additive: Overuse of aftermarket foam inhibitors can cause more harm than good.

How to Troubleshoot Foaming Issues
Traditionally, foaming issues were tackled by repeatedly adding aftermarket antifoam additives—only for the foam to return soon after. Today, a more strategic approach is recommended:

  1. Test the Oil: Conduct a foam test to assess the severity of the issue.
  2. Identify the Root Cause: Use a process of elimination to determine the likely culprit.
  3. Take Corrective Action: Address contamination, mechanical faults, or fluid compatibility issues.
  4. Avoid Overuse of Antifoam Additives: Instead of continuously adding foam inhibitors, resolve the underlying cause.

Need Expert Advice?If you’re facing foaming issues or any other lubrication challenges, our experts are here to help. Drop us an email at info@bcl.co.za, and we’ll provide tailored solutions to keep your equipment running smoothly.

Engine oil deterioration

Engine oil deterioration and deposits: what you need to know!

In our previous blog, we explored the issue of soot in engine oil, which sparked a wave of questions about engine oil deterioration and deposits—specifically sludge and varnish. Let’s dive into how these unwanted by-products form and how they impact your engine.

Why Are Engine Deposits Increasing?
Modern engines are all about efficiency and lower emissions, but these advances come at a cost. Engines now run hotter to improve thermal efficiency, oil drain intervals are extended, and sump sizes are reduced to make engines lighter and more compact. Add to this tighter aerodynamics that reduce airflow around the engine, and you’ve got a recipe for added stress on your engine oil.

Fuel economy demands have also led to the widespread use of lower viscosity oils. While great for efficiency, these thinner oils break down more easily at high temperatures. That’s where the NOACK Volatility Test comes in—it measures how much oil evaporates under heat. When oil evaporates, the remaining fluid thickens, leading to poor circulation, reduced fuel economy, increased oil consumption, and even more wear and tear on your engine.

Sludge vs. Varnish: What’s the Difference?

Both sludge and varnish are by-products of oil degradation, but they differ in appearance and impact.

Sludge is a soft, black deposit that forms in your engine’s oil system. It’s primarily made up of oxidized oil, water, and soot from incomplete combustion. As oil oxidizes—especially when exposed to heat and air—it thickens and forms acids. These acids corrode engine metals, while the sludge increases oil viscosity, eventually turning it into a gel-like substance that blocks oil flow.

Diesel engines are particularly vulnerable because soot from partially burned diesel mixes with the oil, accelerating sludge formation. Once the oil additives are depleted, the sludge hardens and sticks to engine components, restricting circulation and cooling. This can lead to excessive wear or even catastrophic engine failure.

Sludge often starts accumulating in the top end of the engine (under the valve cover) as shown in Figure1 and in the oil sump (Figure 2). If it clogs the oil siphon screen (Figure 3), oil flow stops, leading to inevitable engine failure. The oil level may look fine but the engine is actually being damaged with every revolution of the crank as the engine loses oil pressure and is no longer lubricated effectively. This is a serious issue for many cars built since 1996, hence the introduction of OEM oil specifications such as VW 505.00 and MB 229.3.

Figure 1

Figure 2

Figure 3

Varnish, on the other hand, is a thin, sticky film that forms on internal engine parts. Unlike sludge, varnish is hard and non-wipeable. It results from the gradual oxidation of oil at high temperatures. As oil passes over hot engine surfaces, it oxidizes a little more each time, depleting antioxidant additives and leading to the formation of insolubles. These eventually stick to metal surfaces, creating varnish. Varnish can cause moving parts to stick, leading to malfunctions, excessive wear, and even component seizure (see Figures 4, 5 and 6. It’s often referred to as lacquer, pigment, gum, or resin in the industry.

Figure 4

Figure 5

Figure 6

Other Factors Accelerating Oil Deterioration
• Poor Filtration: Contaminants, wear particles, and water can build up, degrading the oil and accelerating additive depletion.
• Wear Debris: Metals like copper act as catalysts, promoting oxidation.
• Foaming: Contaminated oil can foam, reducing its ability to lubricate effectively.

The Solution: Advanced Lubricant Technology
At Blue Chip Lubricants, we understand the challenges modern engines face. That’s why our high-performance Q8 engine oils are formulated with cutting-edge additive technology designed to combat sludge and varnish. Our oils help minimize deposit formation, ensuring your engine stays cleaner and runs longer.

Need Expert Advice?
If you have questions about lubrication or need help selecting the right oil for your engine, reach out to us at info@bcl.co.za. Our team of experts is ready to assist you in keeping your machines running smoothly.


Stay tuned for more insights on keeping your engine healthy and efficient


Soot in engine oil

Soot is a by-product of combustion and is present in all used engine oils. Soot is generated as a result of incomplete fuel combustion in engines. When the air and fuel mixture that powers the engine fails to burn completely there is leftover matter – partially burned fuel which is generally known as soot. It is a common misconception that soot does not occur in petrol engines, but it does. Soot is, nevertheless, not such a big problem in petrol engines because they combust fuel more effectively than diesel burners. There are several reasons why soot is a serious problem in diesel engines.


To start off diesel fuel is ‘heavier’ than petrol and does not burn as readily as petrol. Secondly, the fuel/air mixture in a petrol engine is ignited by an electric discharge at the spark plug. In a diesel engine the fuel and air ignite spontaneously (auto-ignition) as a result of the high pressure and temperature in the combustion chamber. Furthermore, diesel is only injected into the compressed air in the combustion chamber towards the end of the compression stroke, resulting in poor mixing of the diesel and air. This creates fuel-dense, oxygen lacking ‘pockets’ that produce soot when ignited. Some of this soot comes into contact with the oil film on the cylinder liners. As the piston moves down, soot that is trapped in the oil film is scraped down into the oil sump by the oil control piston ring.


Soot can also reach the oil in the sump via blow-by, i.e. the leaking of partially burnt fuel and combustion gases past the piston rings into the crankcase. This occurs more frequently in engines with worn piston rings. Other factors that can lead to abnormal soot loading of the oil are:
• Frequent stop/start operations.
• Extended periods of idling.
• Incorrect injector spray patterns.
• Rich fuel/air mixtures.
• Blocked air filters.


Individual soot particles are minute and impose little danger to the oil and engine. The soot particles, however, have the tendency to agglomerate (clump together) and form larger clusters. These large clumps of soot can cause damage to the engine, but the dispersant additives in engine oil prevent them from agglomerating and keep them finely suspended in the oil.


When the soot concentration in engine oil reaches a level that can no longer be dissolved by the dispersant additive, the soot particles clump together to form sludge.


The sludge attaches itself to engine surfaces, impedes oil flow through the oil filter as well as the engine and increases oil viscosity with the following devastating results:
• Agglomerated soot negatively impacts the performance of anti-wear lubricant additives and leads to accelerated engine wear.
• Build-up of soot and sludge in the grooves behind piston rings causes rapid wear of the rings and cylinder walls.
• High viscosity results in cold-start problems and risk of oil starvation. This often results in premature engine failure.


Blue Chip Lubricants and Q8 heavy duty diesel engine oils are formulated with the latest generation dispersant additives to keep increased concentrations of soot in suspension for extended periods of time. The formation of soot in modern diesel engines is an ever-increasing reality but the advanced additive technology in our engine oils minimises soot induced wear, controls sludge build-up and resists oil thickening associated with high soot levels.


If you have any questions concerning lubrication, our experts are at your disposal and ready to provide you with advice and guidance. Simply mail us at info@bcl.co.za and put us to the test. You can trust us to take care of your lubrication requirements which will allow you to concentrate on your core responsibilities – managing your assets.