Subaru EZ30 Engine Problems And Specs

This 3-liter engine was put into production in 1999 and was a successor to the EG33 engine. At the time of its production, EZ30 was the flagman engine in the lineup and was installed on the biggest cars. This motor has been designed completely from scratch, he used an aluminum cylinder block height of 202 mm, with cast iron sleeves 2 mm thick. Inside was mounted crankshaft with a stroke of 80 mm, crank length is 131.5 mm, a diameter of the piston 89.2 mm, the height of 30.3 mm, and a compression ratio is 10.7. All this is possible to obtain a 3-liter working volume.

Covered the block with an aluminum head with two camshafts, and 4 valves per cylinder. 254/226 camshafts, climbing 10.0 / 9.5 mm. The camshafts are driven via two timing chains. EZ30 intake manifold made of aluminum with variable geometry, its switching occurs at around 3600 rev/min.

This engine develops 220 hp at 6000 rev/min and torque of 289 Nm at 4400 rev/min. In 2003, there was a restyled engine EZ30D, which is informally called EZ30R. This engine differs a modified cylinder head with recycled channels added system AVCS variable valve timing and valve lift of the intake AVLS (adjustment range 50 °). Valve lifting height depends on speed and has 3 positions: up to 2000 rev/min, 2000-4000 rev/min, above 4000

In 2003, there was a restyled engine, EZ30D, which is informally called EZ30R. This engine differs from a modified cylinder head with recycled channels, added system AVCS variable valve timing and valve lift of the intake AVLS (adjustment range 50 °). Valve lifting height depends on speed and has 3 positions: up to 2000 rev/min, 2000-4000 rev/min, and above 4000 rev/min.

And also, on EZ30R appeared an electronic throttle valve with a diameter of 76 mm, a plastic intake manifold, the MAF is used instead of the MAP, a new exhaust manifold.

Such modifications yielded 245 hp at 6600 rev/min and torque increased to 297 Nm at 4200 r / min. The release of EZ30 continued till 2009, but since 2007 it began to replace

The release of the EZ30 continued till 2009, but in 2007 it began to replace with the EZ36 engine.

Subaru EZ30 Engine Specs

ManufacturerGunma Oizumi Plant
Also calledSubaru EZ30
Cylinder block alloyAluminum
4 valves per cylinder
Piston stroke, mm (inch)80 (3.15)
Cylinder bore, mm (inch)89.2 (3.51)
Compression ratio10.7
Displacement2999 cc (183 cu in)
Power output164 kW (220 HP) at 6,000 rpm
183 kW (245 HP) at 6,600 rpm
Torque output289 Nm (213 lb·ft) at 4,400 rpm
297 Nm (219 lb·ft) at 4,200 rpm
HP per liter73.3
Fuel typeGasoline
Weight, kg (lbs)180 (397)
Fuel consumption, L/100 km (mpg)
Subaru Tribeca
13.3 (18)
9.0 (26)
10.2 (23)
Turbocharger Naturally aspirated
Oil consumption, L/1000 km
(qt. per miles)
up to 1.0
(1 qt. per 600 miles)

Recommended engine oil

for Subaru Impreza

0W-30, 5W-30, 5W-40, 10W-30, 10W-40
Engine Oil Capacity5.7 quarts
Oil change interval, km (miles)5,000-10,000
Normal engine operating temperature, °C (F)90 (194)
Engine lifespan, km (miles)
-Official information

300,000+ (180,000)
Tuning, HP
-Max HP
-No life span loss

Subaru EZ30 Engine Oil Capacity

The Subaru EZ30 engine requires 5.7 quarts of 0W-30 oil with a filter replacement.

What Cars Have A Subaru EZ30 Engine?

  • Subaru Legacy
  • Subaru Outback
  • Subaru Tribeca

Subaru EZ30 Engine Problems And Malfunctions

  1. The noise of the timing chain. Most likely the chain tensioner is faulty and needs to be replaced, along with the timing chain and the entire set.
  2. Overheating of EZ30. Perhaps the problem is in the radiator, check its condition and, if necessary, replace it with aluminum, it will help. If all goes well, then the second option is punched cylinder head gasket. Even if this does not work, then see the pump, thermostat, or there is air in the cooling system.
  3. High fuel consumption. Fuel consumption in the EZ30 is also not the strength of his party.
    All of the above does not happen too often (except fuel) and for the most part, this is an excellent high-torque engine with decent power for normal daily operation. Regular maintenance and the use of normal oil with gasoline will extend the life of the motor to 150,000-180,000 miles (250000-300000 km).

EZ30 Tuning

This engine differs from the strangled exhaust, so by replacing the exhaust manifold and installing the direct-flow tube, you can get a small increase and significantly improve the sound of the exhaust system.

Building a powerful aspirated engine has no sense, so it is much more profitable to follow the path of turbo EZ30.

Good turbo project will also cost quite expensive, because you need to replace the pistons (compression ratio ~ 8.5), connecting rods Pauter, valves, valve springs, plates, buy ARP studs, and if you plan to power more than 400 hp, while highly recommended to buy a sleeve.

Then you need to find the turbine-like Garrett GT3582 and organized the oil flow on it and the oil drain. It is necessary to make the turbo manifolds or buy (if you find), you also need to buy brains VEMS, intake system like K & N, front-mount intercooler, Piping, nozzles by GTR or Tuned from the STI, the fuel pump Bosch 044, fuel regulator, blow off, wastegate, exhaust system 76 mm tube. Set up, by 1 bar of boost you’ll get about 500 hp on the flywheel, which is quite enough for a quiet ride to the store for bread.

You can inflate 400+ hp in the drain motor, not clenched it, but it is a risky business, and make better use of water and methanol injection.

It is possible to go in a simpler way and to order a compressor kit of Raptor, which inflates a 0.5 bar discharge piston and provides a 350+ hp.

Was this helpful?

Thanks for your feedback!

The information provided in this article is for general informational purposes only. The author and publisher make no representations or warranties of any kind, express or implied, regarding the accuracy, adequacy, validity, reliability, availability, or completeness of any information presented. The reader is advised to consult a qualified professional, such as a mechanic or dealership, before making any decisions related to their vehicle's engine oil or maintenance.

About The Author