For the last 5-10 years the topic of “oil addiction” of modern engines is on everyone’s lips. However, for some reason few people remember or know that among the simple old “time-tested” engines there are many “lovers” to eat oil. One of such “gourmets” is 1.8-liter atmospheric engine Nissan QG18DE.
1.8-liter engine Nissan QG18DE belongs to the QG family – this abbreviation can be deciphered as “quality and green”. That is, the entire family is a fairly ordinary motor designed to be installed on mass-produced Nissan models.
The power unit QG18DE was produced from 1999 to 2006. Engines of the QG family were produced from 1999 to 2006 at factories in Japan and, that particularly concerns the 1.8-liter engine, in Mexico.
In our latitudes this engine is found on imported from Europe cars Nissan Primera, Almera, Almera Tino and a little bit on arrived from the USA Nissan Sentra (models B15 and N16).
Nissan QG18DE 1.8 engine specifications
| Characteristics | Parameter |
|---|---|
| Exact volume | 1769 cm³ |
| Power System | Distributed injection |
| Engine power | 115 – 128 hp |
| Torque | 158 – 175 Nm |
| Cylinder block | Cast iron R4 |
| Cylinder head | Aluminum 16v |
| Cylinder diameter | 80 mm |
| Piston stroke | 88 mm |
| Compression ratio | 9.5 – 10 |
| Engine features | EGR |
| Hydrocompensators | No |
| Transmission timing | Chain |
| Fasoregulator | Inlet N-VCT |
| Turbocharging | No |
| Oil | 2.7 liters 5W-30 |
| Environmental class | Euro 3/4 |
| Example service life | 250,000 km |
Nissan 1.8 engine design features
The inline 4-cylinder block of the QG18DE engine is cast iron. The block head is aluminum, with two camshafts that drive the valve train, which has no hydrocompensators. Thermal valve clearances must be adjusted once every 100,000 km by selecting washers (shims).
On the intake camshaft of the QG18DE engine is installed phase shifter NVCT, although there are versions produced without it. The intake manifold is equipped with a mechanism for changing its length. A chain is used in the timing drive.
The timing chain
The timing chain on the Japanese engine is not eternal. In the course of operation, it stretches and begins to rattle. The more the timing chain is stretched, the “brighter” malfunctions in the engine. In particular, it begins to “float” revolutions. Usually the Nissan 1.8 engine chain has to be replaced by the mileage of 150 000 km. By the way, the Nissan engine uses a plate toothed chain (Morse chain).
Why does the Nissan engine consumes oil?
The family includes engines with a volume of 1.3 to 1.8 liters. And to be fair, we note that all of them are “lovers” to eat oil. It is interesting, whether we will find signs of oil addiction in our unit?
The thing is that restyled engines, released in 2003, were noted for their special “oil appetite”. At the height of the problem, cunning engineers and servicemen released information that oil consumption up to 500 grams per 1000 km is not a warranty case. If the engine started to consume more – it was replaced under warranty. However, even on a new engine the problem of oil consumption began to appear at a mileage of 15 000 km.
Decoction, replacement of the membrane (breather) of the crankcase ventilation system, replacement or cutting of the catalytic converter do not affect the oil consumption of QG series engines.
In general, the QG18DE motor is nothing special, and therefore it is difficult to expect big troubles from it. Nevertheless, some features of this motor entail a large investment in repairs.
Wear and galling of piston rings
On the disassembled Nissan 1.8 (QG18DE) engine, we found signs of oil glut. Firstly, the oil rings on all pistons have lodged. Secondly, on the heat belt and on the surface of the piston under the rings there are traces of burning oil.
“Cure” high oil appetite of all engines of QG series can be only one way – to replace the oil rings. And Nissan has not released any alternative improved rings, so the new ones will wear out, and the increased oil consumption will return.
However, among the QG engines there are some that have successfully passed more than 100,000 km without noticeable oil consumption. Thus, this problem is not systematic, but still occurs on most engines.
Other weaknesses of the engine
In the Nissan motor, other malfunctions occur quite often. For example, the block head gasket often burns through. In the plastic valve cover, the glands sealing the candle channels flow. The gasket of the idle valve located near the throttle valve leaks antifreeze, which drips directly onto the electronic engine control unit.