Washing the engine with kerosene: is the game worth the effort?

The question of whether to use kerosene For the internal combustion engine, it's been a hot topic for motorists and service center geeks for decades, and it's a cheap solvent that can handle oily deposits very well, and it's available in any hardware store, and modern motors are precision machines, where the gaps between parts are measured in microns, and seal materials can be sensitive to aggressive chemistry.

Many owners of old VAZ or GAZEL This method is still being successfully used today, adding fuel or kerosene to oil before draining, but in modern foreign cars with turbines and complex lubrication systems, this approach can be fatal. Kerosene does not have oil lubricating properties, which when starting the engine for washing creates an oil starvation mode, critical for friction pairs.

In this article, we will examine in detail the chemical and physical properties of kerosene in the context of a lubrication system, assess the real risks for rubber seals and slip bearings, and compare the effectiveness of the “folk” method with professional washing fluids.

Chemical properties of kerosene and its effect on motor oil

To understand the mechanism of action, you need to consider kerosene It's a mixture of liquid hydrocarbons from direct distillation of oil, and unlike motor oil, which has additive packets (anti-friction, anti-corrosion, detergent), kerosene is chemically inert in terms of protection, but it's active in terms of dissolution.

When kerosene enters the crankcase, it dramatically reduces the viscosity of the base oil. If the standard oil has a certain density at operating temperature and creates an oil film, the kerosene mixture becomes too liquid. oil-pump begins to pump a substance that is unable to withstand high loads in friction pairs.

Technical details of evaporation

Kerosene begins to actively evaporate at temperatures above 40-60 ° C, but in the closed volume of the crankcase this process is slower, creating the risk of steam stoppers in the lubrication channels with a sharp increase in speed.

It is also important to consider the absence of kerosene. antioxidantWhen heated to operating temperatures (90-105°C), it can oxidize faster than specialized formulations, forming resins if the washing process is delayed, which is why the engine should run on such a mixture at a minimum.

• 🧪 A sharp decrease in the viscosity of the working fluid to water level.
• 🔥 Lack of thermal stability during prolonged heating.
• 💧 High penetrating ability, washing out even protective films.

Risks for rubber seals and glands

One of the main arguments of opponents of kerosene washing is its aggressive effect on the skin. rubber products (RTI)Crackshaft oils, valve cover gaskets and oil caps in modern engines are made from various polymers such as fluoro rubber or acrylate rubber.

Kerosene is a strong solvent and can cause swelling or, conversely, drying and cracking of certain types of rubber. If the engine has already installed non-original seals of questionable quality, contact with an aggressive environment can provoke a sudden sudden sudden sudden dislocation of the engine. oil-flowIt's not going to be possible to restore the elasticity of the dried-up oslc anymore, it's going to need a replacement.

⚠️ Attention: If your car is over 15 years old and has a mileage of more than 250,000 km, using pure kerosene can finish off the sulphured oils that have been kept for decades by swelling from old oil.

However, it is worth noting that short-term exposure (5-10 minutes of idling) rarely leads to instantaneous destruction of quality seals. The main danger lies in prolonged contact or use of technical solvents with unknown chemical composition, which are sold for spilling and may contain acetone or other caustic components.

Comparison: kerosene vs. specialized washes

On the shelves of auto shops there is a wide range of flushing-oil What's the difference between them and kerosene? Specialty tools are developed by chemical engineers with the engine under load and at high temperatures.

Professional washes contain detergents and dispersants that not only dissolve the sludge, but also keep it suspended, preventing it from settling back into the channels or clogging the oil receptacle net, but also simply washing away the dirt, which can then rush into the filter or, worse, to bearings with large flakes.

Below is a comparative table showing the key differences in specifications:

Parameter	kerosene	Special washing (5 min)	Washing oil
Lubricating capacity	Missing.	Low.	Medium
Aggressiveness to rubber	High.	Moderate.	Low.
Price per litre	Low.	Medium	High.
Safety for the turbine	Critically low	Low.	High.

As can be seen from the table, the savings on kerosene look questionable against the background of potential risks, especially for owners of turbocharged engines, where the lubrication of turbocharger bearings requires exceptional oil quality even at the time of washing.

In which cases is washing with kerosene permissible

Despite all the risks, there are scenarios where using kerosene or its blend with oil is a justified step. archetypeThey're not equipped with sophisticated electronics, hydraulic compensators, phase changers, for example, classic motors. VAZ 2101-2107 or ZMZ-402 Often washed in this way when switching from mineral oil to semisynthetics.

And kerosene is also effective in mechanically cleaning the parts of the disassembled engine. overhaul And we removed the cylinder head or the pallet, and washing the inner cavities with kerosene with a brush is a great way to remove the residue of the soak and old lubricant before assembly, and in this case, the risk is minimal, because the engine does not start.

Another case is flushing the lubrication system before disposing of the car or before long-term storage of the engine in a warehouse, and if the goal is to remove the old oxidized oil from the crankcase as much as possible without any claims to further exploitation, kerosene will cope with this cheaply and angrily.

• 🛠 Major repairs and washing of removed parts (pistons, shaft).
• 🚜 Maintenance of old equipment without hydricos and turbines.
• 🗑 Preparing the engine for conservation or disposal.

The correct algorithm of actions during washing

If you have weighed the pros and cons and made a firm decision to use kerosene, you must strictly follow the technology to minimize damage.

The process should look like this: drain old oil, twist the cork, pour the mixture (usually 20% kerosene and 80% cheap mineral oil, or pure kerosene only for very dirty engines without pressure). single-turn 5-10 minutes.

After the flushing mixture is drained, be sure to replace the oil filter, as it will contain all the washed-out dirt and dissolved sludge, only after that new, high-quality oil is poured in, ignoring the filter replacement will reduce the entire procedure to zero.

⚠️ Attention: It is strictly forbidden to give the gas or increase the speed above 1000-1200 rpm during washing. The pressure in the system will fall, and the crankshaft inserts may turn due to the low viscosity of the liquid.

Consequences of improper washing for the engine

So what happens when you disrupt the technology, or if you use kerosene where it's not allowed? oil-pumpBecause of the low viscosity of the fluid, its gears can get increased wear and, in the worst case, bullies, which will cause the oil pressure throughout the system to drop in the future.

Second blow takes over hydrocompensatorThese devices work on the principle of precise oil dosing. A flush liquid with slurry particles (which kerosene has successfully washed off the walls but has not dissolved) can jam the plunger pair, resulting in the knocking of the valves and the need to replace the entire gas distribution mechanism.

Also worth mentioning is the risk of clogging the oil receiver: Large pieces of coarse, torn off by an aggressive solvent, may not pass through the filter and remain in the net, causing oil starvation at high revs. This is a direct route to twisting the liners and expensive repairs.

Can kerosene be mixed with diesel fuel for washing?

Mixing kerosene with diesel is a popular “old-fashioned” method, a little fatter than kerosene, but it is still fuel, not lubricant. It is a highly penetrating mixture that can flush the lubricant out of turbine bearings, and it can only be used on very old, simple engines, and then with great care. For modern diesels with pumps, this is strictly forbidden.

How long can I keep kerosene in the engine?

The engine operating time on the mixture with kerosene should not exceed 10 minutes. If you pour pure kerosene (which is extremely not recommended), the time is reduced to 3-5 minutes. Keep the mixture in the engine in the parking lot for hours or days can not be - the process of washing out protective films and possible corrosion effects on non-ferrous metals (sleeves, liners) will begin.

Should I change the oil filter after washing?

Yes, it's a must. The old filter contains a lot of old oil and washed-out dirt. If you leave it, you immediately contaminate the new pure oil. Moreover, when washing, you often use the cheapest temporary filter, which is thrown away with the washing fluid, and a new, quality filter is put under the clean oil.

Is kerosene dangerous for the catalyst?

Yes, it's extremely dangerous. The combustion products of kerosene and washed-off can quickly disable the catalytic converter and the lambda probes. If you have these environmental cleanup elements installed on your car, it's not advisable to wash the engine with any aggressive hot-start method. It's better to use soft oil additives before replacing.

Which is better: washing with oil or kerosene?

Washing with a special wash oil (which is poured for 15-20 minutes of operation) is significantly safer than kerosene. It has the necessary viscosity and additive package to protect the engine in the process. Kerosene is a last resort for very contaminated old engines when other remedies do not help, and the risk of mud jamming is higher than the risk of wear from washing.