Toyota is known for quite a few things. Among them is their capability to build excellent engines. Most Toyota engines don’t have the quickest acceleration times or the highest top speed. Sure, the likes of the 2JZ shatter this statement, but most engines Toyota makes are mainly focused on being reliable and efficient. Power comes first only in a handful of cases. While it depends on the vehicle, the company’s mass-market offerings are certainly aimed toward delivering a trouble-free, but competent ride.
The 3RZ engine from Toyota is one such case. Designed for use in the company’s off-road and commercial vehicles, it has made quite a name for itself. That being said, even the most reliable engines have a few problems. We’ll cover the ones that you should know about, especially prior to buying a car with the 3RZ engine. We’ll also discuss the 3RZ engine’s highlights and why it could be the ultimate Toyota truck powerplant.
Toyota 3RZ Engine — The Introduction
The 3RZ-FE or 3RZ engine superseded the company’s 22R-E engine in 1994. With a displacement of 2.7 liters, this engine was quite sizable when you consider its inline-four cylinder configuration. The higher displacement was a must because the vehicles this motor would fit were mostly utilitarian in nature. And it served this function incredibly well. So much so that Toyota used the 3RZ engine for 10 years (1994 to 2004).
This engine was manufactured by Toyota at their Kamigo Plant in Japan and would find its way into Toyota’s most popular offerings like the Tacoma, Land Cruiser Prado, and the 4Runner. All of these vehicles used the 22R-E up until that point and were in a dire need of an upgrade.
Interestingly, the 3RZ engine only made 150 hp at 4,800 RPM and 177 lb-ft of torque at 4,000 RPM. That isn’t much when you consider its size. However, this motor was never meant to be setting quarter-mile times. Instead, it was meant to be reliable to a fault. It was the Toyota Corolla of utility vehicles, and it performed just as well.
Which Vehicles Got the 3RZ Engine?
As mentioned earlier, Toyota designed this engine for heavy-duty vehicles and a lot of them can be seen plying the roads even today.
- 1995–2004 Toyota Tacoma
- 1996–2000 Toyota 4Runner
- 1995–2004 Toyota Hilux
- 1990–2004 Toyota Hiace
- 1994–1998 Toyota T100
- 1995–2002 Granvia
- 1998–2002 Toyota Touring Hiace
- 1996–2004 Toyota Land Cruiser Prado
What’s Inside the 3RZ Engine?
The 3RZ engine uses a cast iron cylinder block with a deep-skirt design. Toyota engineers went with the bore and stroke of 95.0 mm, making it a square configuration. Along with the forged crankshaft, the engine uses eight counterweights and carbon steel connecting rods that are also forged. These are paired with aluminum pistons that feature resin-coated skirts. This engine also accommodates four valves per cylinder and a dual overhead camshaft arrangement.
The 3RZ engine makes use of a timing chain and not a timing belt which increases its service life while decreasing major service cycles. However, this engine doesn’t have hydraulic lifters which means the valve clearances need to be adjusted every 25,000-30,000 miles. The engine also makes use of an intake manifold that’s made from lightweight aluminum. The manifold has been designed with the intent to increase torque. Toyota achieved this with the help of two intake runners per cylinder.
3RZ Engine Common Problems
Despite being super reliable, the 3RZ engine won’t be able to escape from a list of common problems. Here’s everything you need to know to keep your engine in the best shape possible.
Valve Adjustment
When it comes to the 3RZ engine, it is quite widely known that it needs a valve adjustment quite frequently – every 25,000-30,000 miles to be precise. While this is more a maintenance procedure than a problem, it has to be mentioned given its frequency. The need for valve adjustments occurs due to the camshaft, valve seats, and valve slowly wearing down.
When you ignore this part of maintenance, the exhaust valves move out of spec and end up not closing fully, which in turn causes them to burn. Proper clearance is a must as the only way to fix this problem would be by replacing the valves. That’s an expensive repair and one that can be easily avoided by carrying out timely valve adjustments.
Valve adjustment on the 3RZ engine isn’t too difficult, but you have to know what you’re doing. Feeler gauges alone won’t cut it. Knowing how much clearance each valve group needs is key.
Timing Chain Stretch
Several Toyota engines use timing chains instead of timing belts and the 3RZ engine is one of them. Timing chains work similarly, but make use of gears to connect the crank and the cam. The efficiency of the timing chain also depends on the other components like the tensioners and timing chain guides that it makes use of. All of these components also require a specific amount of oil pressure to work correctly, and any inconsistencies can lead to problems.
Like the valve adjustment requirement, timing chain failure is also a result of a lack of maintenance. The 3RZ engine has a timing chain that has a lifespan of 150,000 miles. However, it is recommended that you inspect it once you cross the 100,000-mile mark. Timing chains show signs of wear by stretching over time.
This is normal, and they usually need to be replaced before things get out of hand. An overly stretched chain will jump timing, at which point pistons shake hands with valves and no one has a good time.
Just like with most things automotive, preventative maintenance is everything. You can greatly extend the life of your timing chain by performing timely oil changes and using quality oil. Also, avoid lugging the engine as that puts a high amount of strain on the chain.
Serpentine Belt Wear
The serpentine belt is also known as the accessory belt. This belt is responsible for running systems like the power steering, alternator, and air-conditioning, among other things. As you can imagine, this rubber belt undergoes a large amount of stress and heat tends to wear out.
The serpentine belt on the 3RZ engine is known to last up to the 100,000-mile mark before failing. Naturally, we recommend replacing it much sooner than that as prescribed by Toyota. It’s a good idea to inspect the belt from time to time. If you see cracks, fraying, or lack of flexibility in the belt, it’s time for a replacement.
Bad Balance Shaft Bearing
The 3RZ engine makes use of two balance shafts. These shafts are used on inline-four cylinder engines to help cancel out the vibration made by the engine. They do this by rotating in the opposite direction at twice the speed of the engine. These shafts depend on bearings to carry out the high-speed rotation. These bearings tend to fail.
That said, this problem has been noticed more frequently on the 3RZ engine sold in Venezuela between 2001 and 2009. While the most common fix to this would be to replace the bearing, there is a company that offers a kit that deletes the balance shaft altogether. Symptoms of this problem include excessive engine vibration, as the functioning of the component becomes inconsistent.
Water Pump Failure
Like the majority of 3RZ engine common problems listed above, water pump failure is related to maintenance. Water pumps serve the all-important purpose of maintaining engine temperature. The water pump the 3RZ engine uses is belt-driven and powered by the serpentine belt.
While belt-driven water pumps are known to last long, they still wear out over time. Internal seals, pulley bearings, and other things will fail after a while. Once that happens, you’re risking overheating the engine. There are usually no symptoms of water pump failure which means it can suddenly fail without warning.
It’s also quite difficult to tell when the water pump on the 3RZ engine will fail as some tend to do as early as 75,000 miles, while some keep going till the 300,000-mile mark. The best way to ensure your water pump doesn’t fail is by replacing it when the service manual recommends doing so.
Why Buy the 3RZ Engine?
The main reason to buy the 3RZ engine is that it’s a tough little engine. It’s an economical workhorse that offers bulletproof reliability. The vehicles this engine has been used in are known to be amongst the toughest vehicles in the world.
The Toyota Hilux, for example, is a pick-up that’s being used in the deserts of Saudi Arabia and on the snow-clad mountains of Nepal. It’s taking on extreme temperatures while carrying a huge payload and its powertrain deserves a large amount of credit for this. Prices of used 3RZ engines are also quite affordable when you factor in its rock-solid forged crank and cast-iron block.
Get Your 3RZ Engine Parts at Newparts
Here at Newparts.com, we carry a wide range of spares for the 3RZ engine. We offer anything from Genuine Toyota to OEM and quality aftermarket. To find the parts that you’re looking for, head over to our store and select your vehicle using our vehicle selection tool. That way our system will only return products that are a guaranteed fit for your car.
