The turbocharged Nissan VQ30DET engine was produced from 1995 to 2007 and was installed in a number of premium models of the concern, including Nissan Cima, Cedric, Gloria and Leopard. The engine is characterized by powerful performance and modern at that time technical solutions, such as ECCS (Electronically Concentrated Control System) and NDIS (Nissan Direct Ignition System). There was also a twin-turbocharged version under the index VQ30DETT.
Main Technical Specifications
| Characteristics | Reference |
|---|---|
| Exact volume | 2987 cm³ |
| Power system | distributed injection |
| Power | 270 – 280 hp |
| Torque | 365 – 385 Nm |
| Cylinder block | aluminum V6 |
| Cylinder head | aluminum, 24 valves |
| Cylinder diameter | 93 mm |
| Piston stroke | 73.3 mm |
| Compression ratio | 9.0 |
| Features | ECCS, NDIS |
| Hydrocompensators | no |
| Transmission timing | three chains |
| Fasoregulator | no |
| Turbocharging | one Garrett turbine |
| Oil volume | 4.0 liters, 5W-30 recommended |
| Environmental class | EURO 3/4 |
| Example service life | 300,000 km |
| Weight | 230 kg |
Application of the Engine on Nissan Cars
VQ30DET was installed on premium Nissan models, providing them with high power and reliability. The main models equipped with this engine are:
- Nissan Cima: 3rd generation (Y33), production 1996-2001; 4th generation (F50), production 2001-2007.
- Nissan Cedric: 9th generation (Y33), production 1995-1999; 10th generation (Y34), production 1999-2004.
- Nissan Gloria: 10th generation (Y33), 1995-1999 production; 11th generation (Y34), 1999-2004 production.
- Nissan Leopard: 4th generation (Y33), production 1996-1999.
Main Flaws and Problems with Nissan VQ30DET
Elevated Oil Consumption (“Oil Hogging”)
Owners often complain of increased oil consumption, especially at high mileage. This is due to the fact that scoring can occur in the cylinders. The main reason is the ingress of crumbs from the deteriorating catalyst into the combustion chamber. The abrasive particles scratch the cylinder walls, causing wear and increased oil consumption.
Cylinder Head Crushing (CCH) due to Overheating
Overheating of the engine can cause warping of the cylinder head mating surfaces. This engine does not always cool easily under heavy load conditions, especially when operating at high speeds. If the cooling system is inefficient or there is a shortage of coolant, overheating will warp the cylinder head, requiring serious repair.
Stretching Timing Chains
By about 200,000 km, the timing chains begin to stretch excessively, resulting in a characteristic “rattle” when the engine is running. Loose chains reduce timing accuracy and can lead to engine malfunctions. Replacing the timing chain in this engine is a fairly expensive procedure, especially because of the complex triple chain design.
Swimming RPMs at idle
In some cases, the engine may run intermittently at idle, especially if the idle valve is contaminated. The contamination is caused by deposits from oil and fuel combustion and disrupts the valve, resulting in erratic engine idle speeds.
Plastic Valve Cover
The VQ30DET’s valve cover is made of plastic, which causes a lot of complaints from owners. Not only is the cover subject to wear and tear, but it also includes integrated plug well oil seals that are only replaced with complete disassembly of the cover. This approach makes servicing and replacing the oil seals more difficult, increasing the labor-intensive nature of the repair.
Inconvenient Maintenance
The design of the Nissan VQ30DET engine makes it difficult to access certain components, making maintenance inconvenient. For example, replacing the spark plugs requires removing the throttle piping, and getting to the starter requires lifting the engine, which almost equates to removing it.
Nissan VQ30DET Repair and Maintenance Features
Regularly check the catalytic converter and remove if necessary
To prevent cylinder scoring, it is recommended that the condition of the catalytic converter be checked regularly. If the catalytic converter begins to deteriorate, replacing or removing it (provided it meets environmental requirements) can prevent abrasive particles from entering the cylinders.
Cooling System Control
Given the engine’s tendency to overheat, it is important to keep the cooling system in good condition. Regular coolant changes, radiator cleaning and thermostat checks will help prevent overheating and reduce the risk of deformation of the cylinder head.
Replacing the Timing Chains
Routine replacement of timing chains is recommended at around 200,000 kilometers, especially if characteristic noises appear. Regular inspection and keeping the chain tensioning system in good condition will help extend the life of the engine.
Cleaning the Idle Speed Valve
To eliminate the problem of floating revs, you should regularly clean the idle valve of deposits. This can be done as part of a routine service to avoid unstable engine running at low revs.
Replacing Oil Seals and Valve Cover Maintenance
Because of the nature of the plastic valve cover, its inspection and maintenance is of particular importance. Replacing oil seals and adjusting the cover helps prevent oil leaks and avoids contamination of the spark plug wells. If necessary, the plastic cover can be replaced with an aluminum counterpart (if commercially available) to reduce the risk of wear.