Owners of a popular crossover Nissan Qashqai They are increasingly faced with the problem of increased engine oil consumption. This phenomenon, known among motorists as “oil burner,” can manifest itself both at 60 thousand and at 150 thousand kilometers. Ignoring the problem leads not only to financial losses on the purchase of oil, but also to critical wear of the cylinder-piston group, which is fraught with major repairs.
The situation is aggravated by the fact that the symptoms are often similar to other malfunctions. You need to be able to distinguish natural waste from serious damage, so as not to replace expensive parts in vain. In this article we will look in detail why Nissan Qashqai starts to eat oil and how to fix it.
The main reasons for increased oil consumption on different engines
The causes of oil burn strongly depend on the type of power unit installed. On gasoline engines of the MR family (1.6 and 2.0 liters), the problem often lies in the design features of the piston group, while diesel versions of the 1.5 dCi suffer from other nuances. Oil consumption higher than normal may be the result of both natural wear and tear and manufacturing defects.
The crankcase ventilation system is considered the most vulnerable point. If it is clogged, the pressure inside the engine increases and oil is forced out through the oil seals and oil seals. In addition, at high mileage, coking of the piston rings occurs, which impairs their mobility and tightness.
For owners Nissan Qashqai with the 1.6 engine (MR16DDT) there is a problem with scoring in the cylinders. This occurs due to overheating and insufficient lubrication in areas of maximum load. Cylinder seizure - this is a fatal malfunction that requires immediate stoppage of operation and serious repairs.
Diagnostics: how to understand that the engine is eating oil
The first signal is the need to add oil between scheduled maintenance. If you notice that the level on the dipstick drops by more than 0.5 liters per 1000 kilometers, this is an alarming sign. Do not wait until the oil pressure light comes on, as at this point the engine may already be irreversibly damaged.
The second indicator is the color of the exhaust gases. Blue or gray smoke from the chimney, especially during acceleration or after starting a cold engine, indicates combustion of oil in the combustion chambers. However, the absence of smoke does not guarantee the absence of a problem, since oil may escape through the ventilation system or external leaks.
It is important to visually inspect the engine for leaks. Owners often confuse oil leaks with a normal leak of crankshaft seals or valve cover. Check the condition of the spark plugs: if they have black oily deposits on them, then the oil is definitely getting into the combustion chamber.
⚠️ Attention: Do not try to diagnose oil burn immediately after an active trip. Allow the engine to cool and stand on a level surface for 10-15 minutes to accurately measure the oil level.
- ✅ Check the oil level on a cold engine using the dipstick.
- ✅ Inspect the exhaust pipe for oil leaks.
- ✅ Measure compression in all cylinders to assess the condition of the rings.
Problems with MR16DDT and MR20DD engines
MR series motors installed on Nissan Qashqai since 2014, have a number of specific diseases. The main reason for oil leakage here is a design defect in the piston rings. They are too narrow and prone to rapid coking when using low-quality fuel or oil.
When coking occurs, the oil scraper rings lose mobility and stop removing the oil film from the cylinder walls. As a result, the oil burns along with the fuel. This not only leads to increased consumption, but also clogs the particulate filter on hybrid versions and the catalyst.
Another major problem is bullying. Due to engine overheating, which often occurs during intense driving in traffic jams or at high speed, microcracks and scratches appear on the cylinder walls. Seizure of cylinder walls leads to the fact that the rings cannot provide a tight seal, and the oil goes into the combustion chamber.
- 1.6 MR16DDT
- 2.0 MR20DD
- 1.5 dCi K9K
- Other
Removing oil stains: repair and restoration methods
The solution to the problem depends on the degree of engine wear. If the problem is only ring coking, decoking can help. This is a chemical cleaning procedure for the piston group, which restores the mobility of the rings. However, in case of serious scuffing or wear of the cylinder walls, chemistry will not help.
If scoring or critical wear of the rings is detected, a major overhaul will be required. This includes boring cylinders for repair pistons or replacing liners. For engines Nissan Qashqai The honing method is often used, followed by the installation of new piston rings.
Also, we must not forget about replacing the valve cover gasket and valve stem seals. On runs over 100,000 km, rubber seals become tanned and cease to perform their functions. Replacing the caps is a cheaper procedure than replacing the piston group, and can sometimes reduce consumption.
☑️ Checklist before engine repair
⚠️ Attention: If there are deep scuffs on the engine, decoking can only worsen the situation by clogging the oil channels with decay products.
- ✅ Replacement of oil seals (valve seals).
- ✅ Decoking of piston rings using special chemicals.
- ✅ Replacement of the piston group and boring of the cylinders (overhaul).
The influence of the crankcase ventilation system on oil consumption
The crankcase ventilation (PCV) system plays a critical role in normal oil consumption. If the PCV valve gets stuck open or the diaphragm ruptures, the vacuum in the intake manifold begins to draw oil directly from the crankcase into the cylinders.
On engines Nissan Qashqai this system is often integrated into the valve cover. Replacing an entire vent assembly can be expensive, but sometimes a simple cleaning or replacement of the diaphragm will help. Ignoring a PCV malfunction leads to the fact that even new rings will not be able to retain oil.
The operation of the ventilation system should be checked at every oil change. If thick smoke comes out of the neck or a whistle is heard when the valve cover is removed, the system is not working correctly. Faulty ventilation system - one of the most common reasons for the false diagnosis of oil glutton.
Before changing the oil, check the operation of the PCV valve: remove the hose from the valve cover and check whether oil is leaking from there while the engine is running.
Sometimes the problem is solved by installing an oil separator in the ventilation system. This device separates the oil mist from the air before it enters the intake manifold. This is especially true for cars that are often driven in city traffic with frequent stops.
How to properly maintain an engine to prevent oil burns
Prevention is always cheaper than repair. For engines Nissan Qashqai It is critical to use only high-quality motor oils recommended by the manufacturer. The use of cheap analogs accelerates the formation of soot and coking of the rings.
Reducing oil change intervals is one of the most effective ways to extend engine life. If the factory recommends changing the oil every 15,000 km, then in city conditions it is better to do this every 7,000 - 8,000 km. Frequent replacement washes away wear products and carbon deposits, preventing them from settling on the rings.
It is also important to monitor the engine temperature. Overheating is the main enemy of the piston group. Checking the cooling system, replacing antifreeze and checking the operation of the thermostat should be regular. Engine overheating leads to expansion of the pistons and disruption of clearances, which causes scuffing.
| Engine type | Recommended oil | Replacement interval (city) | Critical consumption (l/1000 km) |
|---|---|---|---|
| 1.6 MR16DDT | 5W-30 / 0W-20 | 7,000 km | more than 0.5 |
| 2.0 MR20DD | 5W-30 | 7,000 km | more than 0.5 |
| 1.5 dCi K9K | 5W-30 (Low SAPS) | 8,000 km | more than 0.7 |
| 2.0 dCi R9M | 5W-30 (Low SAPS) | 8,000 km | more than 0.6 |
Regular oil changes and the use of high-quality lubricants are the most effective way to prevent ring coking on Nissan engines.
Specifics of diesel engines K9K and R9M
Diesel versions Nissan Qashqai are also susceptible to oil burn, but the reasons are different. The main enemy of a diesel engine is the diesel particulate filter (DPF). If the filter is clogged, pressure in the exhaust system increases and oil is forced out through the turbine and engine seals.
On 1.5 dCi (K9K) engines, a problem often arises with valve stem seals, which become tanned due to high temperatures and carbon deposits. A turbine malfunction is also typical when, due to shaft wear, oil goes directly into the intake manifold.
Particular attention should be paid to the exhaust gas recirculation (EGR) system. A clogged EGR valve promotes the rapid formation of carbon deposits on the pistons and valves, which accelerates coking of the rings. EGR and DPF cleaning should be part of routine maintenance.
Why does a diesel Qashqai eat oil when cold?
On a cold engine, the oil viscosity is higher, and if the caps are oak, the oil flows into the cylinder. When started, it burns, producing bluish smoke, which disappears as it warms up.
When diagnosing a diesel engine, it is important to check the turbine for play. If the turbine shaft has axial or radial play, oil will inevitably leak into the engine or exhaust. Replacing the turbine in this case is inevitable.
Why does Nissan Qashqai eat oil at idle?
At idle speed, the oil pressure in the system is minimal. If the oil seals are worn or worn out, oil flows down the valves into the cylinder. As the rpm increases, the pressure increases and the oil is retained better. This is a classic symptom of worn valve seals.
Is it possible to drive if the engine is burning oil?
Short-term - yes, but only if the oil level is constantly monitored. If the level drops below the minimum, the engine may seize. Regular oil loss leads to contamination of the ventilation system, catalyst and the appearance of scoring. You cannot drive with an oil burner without repairs.
What is better: decoking or replacing rings?
Decarbonization is effective only in the initial stages, when the rings are simply stuck. If there is scoring or wear on the cylinder walls, chemistry will not help, but will only worsen the situation. In such cases, mechanical replacement of the piston group is necessary.
Does driving style affect oil consumption?
Yes. Frequent hard acceleration and driving at high speeds increase engine temperature and crankcase pressure, which accelerates oil burnout. A calm driving style prolongs the life of the piston group and reduces oil consumption.
How much oil can an engine consume in 10,000 km?
Consumption of up to 0.5 liters per 10,000 km (or 0.05 l/1000 km) is considered normal. If the engine consumes more than 1 liter per 10,000 km, this is considered a malfunction that requires diagnosis and repair.
⚠️ Attention: The critical level of oil consumption is considered to be 1 liter per 1000 km., in which the operation of the vehicle is prohibited until the malfunction is eliminated.