The 90s and 2000s created a massive bridge for us to experience the best engines in that era. The JDM legend continues as these engines continue to top the engine charts even at their relatively decades-old engine production and release.
However, you cannot deny that they will still dominate and thrive, even competing with the recently developed engines. And one of those engines is the QR20 engine, the engine that replaced the legendary SR20DE motor.
So, let us talk about the QR20DE’s engine design, power output, abilities, tuning potential, aftermarket support, issues, problems, reliability, and many more.
What are QR20DE Engines?
Nissan QR20DE is an inline-four, water-cooled, four-cylinder, 2.0 L gasoline engine manufactured by Toyota from 2000. It first appeared in the Nissan X-trail.
QR20DE features a new aluminum cylinder block and modified cylinder head, double overhead camshaft design with four valves integrated with continuously variable valve timing (CVTC) on the intake camshaft, individual ignition coils, two balancer shafts for an even and smoother operation, electronic throttle body, and multi-point injection system.
QR20DE engines are part of the QR family of engines with different capacities ranging from 2.0 L to 2.5 L. QR20DE engines replaced the iconic SR20DE engines.
Engine Specifications and Design:
- Production Run: 2000 – Present
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Aluminum
- Configuration: Inline-4
- Bore: 89 mm
- Stroke: 80.3 mm
- Valvetrain: DOHC with four valves per cylinder
- Displacement: 2.0 L (1998 cc)
- Compression Ratio: 9.9
- Weight: 330 lbs.
- Max HP: 148 HP at 6,000 RPM
- Max Torque: 148 lb-ft at 4,000 RPM
The Nissan QR20DE engine has a lightweight engine design starting from its Aluminum cylinder block. It has an engine bore of 89 mm, piston stroke of 80.3 mm, and a 9.9 compression ratio.
The pistons are each fitted in a single oil ring and two compression rings. The connecting rods are made of high-strength forged steel that is 153 mm long. The crankshaft of the QR20DE is supported by five main bearings and two balancer shafts.
The engine’s cylinder head is made from Aluminum to go with the two chain-driven camshafts. It is also integrated with continuous variable valve timing on the intake camshaft.
The size of the intake valves is 35 mm in diameter, exhaust valves are at 30 mm, and intake duration of 236 degrees. The QR20DE engine uses special valve lifters to adjust the valve clearance instead of the hydraulic lifters.
This engine produces 138 hp at 6,000 RPM and 148 lb-ft of torque at 4,000 RPM.
There is a QR20DE variant under the QR20DD name. It holds similar attributes to the QR20DE engine but features NEO direct injection for an improved fuel economy and reduced emissions. QR20DD produces 148 HP at 6,000 RPM and 148 lb-ft of torque at 4,400. By the numbers, they are almost identical also, to add to that.
Applications of the QR20DE Engine:
- 2001 – 2007 Nissan X-trail T30
- 2001 – 2007 Nissan Primera P12
- 2002 – Present Nissan Serena C24
- 2003 – 2008 Nissan Teana J31
- 2001 – 2005 Nissan Wingroad Y11
- 2002 – 2005 Nissan Avenir W11
- 2001 – 2004 Nissan Prairie M12
- 2007 – Present Nissan Atlas F24
Engine Tuning, Upgrades, and Modifications
QR20 engine is a good platform for tuning and modifications. One of our main focuses in this tuning setup is to allow a steady stream of power gain for you to enjoy.
The first thing to modify is your cam profile, as it plays a critical role in determining the engine’s power output. The intake and exhaust duration will change depending on the cam profile chosen.
You can opt to use fast road cams which is to increase the hp but compromises the rev range and lower down torque. Competition cams, however, will increase the higher-end RPM range power band, but the downside is the car will idle smoothly, and the lower-end power band suffers.
Usually, there are three stages for modification. But the initial process always starts at ECU mapping that allows a tuner to unlock the tuning potential and of all the tuning parts of the engine, in this case, the QR20DE.
Typical stage 1 mods include panel air filters, drilled and smoothed airbox, performance exhaust manifold, fast road camshaft, intake headers, and remapping.
To proceed, stage 2 mods include fuel pump upgrades, fast road cam, high flow fuel injectors, induction kit, performance exhaust, performance catalytic converter, ported, and polished head.
The last leg for the upgrade is the stage 3 mode that includes: adding forced induction, competition cam, crank, and piston upgrades to change the compression ratio, bigger valves, engine balancing and blueprinting, and twin charging conversions.
In addition to the aforementioned guide, you can acquire more additional power by purchasing a balancer shaft removal kit, installing headers, a cat-back performance exhaust system, and adjusting the ECU.
This can give you roughly around 20HP. QR20DE engine can push it to 200 HP, but you need to install aggressive JWT S1 264/244-degree cams, larger valve springs, and do some head porting.
It is not recommended to bolt in QR25DE turbo in your QR20DE engine because it might just blow up.
Problems Surrounding QR20DE Engines:
The service life of the QR20DE is around 120,000 miles, and some owners experienced the least reliable engine in QR20DE.
Though some of them favor the predecessor over the present QR20DE engine, we cannot alter the fact that whatever engine you have, you have to take care of it to maximize its performance and longevity, which is not an easy task.
We want our engines to stay in peak condition and at best. But there are external factors that might affect that goal. In QR20DE machine, it does have some issues that need to be addressed to have a precautionary heads-up, especially if you want to own or purchase a QR20DE engine.
Here are some issues that might affect your QR20DE engine.
The first thing is the QR20DE engine is difficult to start. This issue is prevalent among engines that stay in colder areas. QR20DE spark plugs might be damp and have a hard time sparking due to this very reason as they have little to no resistance to the said problem.
In connection to the wet spark plugs, this component might also be frozen or faulty. So you might have to check that.
Next is the oil leak in the gasket. Oil leak in the gasket is mainly caused by worn out or loose gaskets.
Due to the harsh conditions that these gaskets undergo from high temperature and fluctuating cooling processes, some gaskets cannot withstand such states for a long time that causes them to be brittle and eventually be an avenue and passage for oil leaks. Always check the gaskets for this kind of issue and replace them immediately.
There are also reports that the QR20DE engine is an oil eater or consumes excessive oil. The age of the engine itself causes this. Since QR20DE machines are produced a decade or two ago, the piston rings, valve seals, and other moving components might be already loosed and needs some replacement.
If your engine oil consumption exceeds the 1qt per 1500 miles, then it is best to replace the parts mentioned above.
The QR20DE engine also has jerking and idle problems. First-generation machines are the most affected by this. This issue might be due to the situation in the stretched timing chain, dirty throttle valves, clogged air filters, and faulty spark plugs and wires.
To add, idle problems are due to inconsistent fuel combustion in the combustion chamber that causes shakes and rough idle in the engine.
Another issue to deal with, with the QR20DE engine is the thermostat. The thermostat in the QR20DE engine is like an eclipse waiting to happen anytime as their service life does not last long.
When a thermostat fails, it is highly detrimental to the engine as they are the indicator and teller of the operating temperature. So, when a malfunction happens, that can directly result in engine overheating, and worse, it might affect the engine’s performance that leads to engine failure.
QR20DE engine is commonly struck out due to its faulty thermostat, issues, and other significant problems. And it is also affected by the shared experiences of the owners because they can attest to the performance and ability of the engine.
It left some sour aftertaste due to its shortcomings, such as its tuning potential, aftermarket support, and general vital features. However, this is still a pretty solid engine, modern and producible at times that can satisfy your daily driving but, unfortunately, cannot be leaning more on the sporty side.
Though it is plagued more of a bad rap, with the proper maintenance, care, regular checking of the engine components, this engine delivers and can service you at least 160,000 miles. And QR20 won’t disappoint your driving experience; because the driving experience is more vital in opting for your engine choice.
I hope that this simple guide and discussion helped you understand the QR20DE’s engine design, power output, applications, tuning potential, aftermarket support, issues, problems, and overall impact on the automotive industry and community.