The 5 Most Common Toyota 3RZ-FE Engine Problems

Toyota’s 3RZ-FE engine is a 2.7L inline-4 which was produced from 1994 until 2004. The 3RZ was replaced with the 2.7L 2TR-FE. Producing only 150hp and 177lb-ft. of torque, the engine was over engineered in a good way. Featuring a forged crank and rods, the strength of this engine combined with its modest power levels results in a highly reliable engine. Then again, all engines are prone to issues and there isn’t an exception here. In this article, I discuss Toyota 3RZ-FE engine problems and reliability.

Toyota 3RZ-FE Engine Problems

• Timing Chain Failure
• Squeaking Serpentine Belt
• Bad Water Pump
• Valve Adjustments (causes burnt exhaust valves from lack of adjustments)
• Balance Shaft Bearing Failure

Before we dig into the common problems on the 3RZ I wanted to reiterate the reliability of this engine. Not all of these problems are necessarily common, some are maintenance items that need to be replaced eventually.

1. Timing Chain Failure

The 3RZ engine is timing chain driven instead of timing belt driven. Timing chains open and close the exhaust valves via a set of gears connected by a chain. The timing chain connects to the cam and crank via a set of gears that sit on the front of the engine block. A timing cover protects the chain and provides oil lubrication.

In addition to the chain itself, the 3RZ-FE also has timing guides and tensioners. The guides prevent the chain from falling off of the gears. Tensioners use springs to prevent slack in the chain. The tensioner in this Toyota engine is hydraulically actuated by oil pressure, meaning a drop in oil pressure will cause tensioners to stop working.

Timing chain failure isn’t necessarily a common problem but more of a maintenance item. Toyota claims the chain is intended to last 150,000 miles before it should be replaced. We recommend inspecting the chain if you are above the 100,000 mile mark.

Since chains are made of metal they naturally stretch over time from constant expansion and contraction from heat cycles. This stretching can cause the chain to loose and jump gears. When the timing chain jumps gears it throws all the timing off which can cause misfires, poor performance, and even catastrophic engine damage.

Symptoms

• Cylinder misfires
• Metal shavings in the oil
• Rattling noise from engine
• Poor idling and performance

While the timing chain naturally stretches over time, there are two other things that can cause premature failure. Engine overheating can cause premature stretching which can lead to failure. Secondly, low oil pressure can cause the timing chain to be starved of lubrication which also causes failure.

We have seen 3RZ timing chains go beyond 200,000 miles without any issues. So while 150,000 miles is the recommended service interval, our recommendation is to have it inspected frequently and replace it when it needs replacing. Timing chains usually fail slowly over time and not instantly so you should have some warning signs before things get too bad.

2. Squeaking Serpentine Belt

A serpentine belt is a long rubber belt that supplies power to various engine systems. Using pulleys and a tensioner the serpentine belt transfers power to things like the power steering pump, alternator, air conditioning compressor, and water pump. The rotational power comes from a pulley that is attached to the crankshaft. As the crankshaft turns, so does the pulley which rotates the belt, driving the other systems.

On the 3RZ-FE engine, the serpentine belt is known to begin squeaking around the 80,000 to 100,000 mile mark. While a squeaking serp belt isn’t necessarily a problem, it does forewarn us that the serpentine belt is on its way out the door. Therefore, when the belt begins squeaking we recommend replacing it.

Serpentine belts are rubber and have grooves on them. Over time the friction wears down on these which can loosen the fit. When the belt is loose it begins to slip which is what causes the squeak. Additionally, a bad pulley or tensioner can also cause the squeak. Fortunately, the belt is usually the reason for the squeak.

Replacing the belt is the simplest way to fix the issue. While you might be able to live with the squeak, it means the belt is about to completely fail. Serp belts are like $10 so just replace it before it takes out all of your major engine systems.

Bad Serpentine Belt Symptoms

• Squeaking or squealing
• AC doesn’t work
• Car doesn’t have power steering
• Battery is low
• Belt is visually worn or frayed
• Overheating (from water pump not working)

3. Water Pump Problems

Again water pump failure is less of a common problem and more of a regular maintenance item. Water pumps are responsible for circulating coolant throughout the engine. The pump operates under high pressures which mean its internal components are prone to normal wear and tear and deterioration.

The 3RZ-FE water pump is belt-driven, meaning it is powered via the serpentine belt. While this improves durability, the internal components can still wear down. Water pumps have what’s called a weep hole or vent hole in them. The weep hole allows either coolant or oil to seep out of it to prevent cross-contamination of these systems.

When the oil seal starts going bad oil will leak from the hole. When the internal water pump seal starts going bad coolant will leak from the hole. Unfortunately, on the 3RZ the water pump usually fails instantly instead of providing some warning signs that it is going out.

We have seen water pumps fail as early as 75,000 miles and last as long as 300,000 miles. However, most water pumps will likely fail around the 150,000 mile mark.

Water Pump Failure Symptoms

• Engine overheating
• Check engine light
• Coolant leaking from the water pump
• Whining noises from the pump
• Leaks from the weep hole

If you have a bad water pump, you can check out our guide on water pump replacement costs.

4. Valve Adjustment and Burnt Valves

The 3RZ engine requires valve adjustments every 25,000-30,000 miles per Toyota. Valve clearance changes over time as the camshaft, valve seats, and valves themselves wear down. On the 3RZ-FE the valve lash decreases which causes the exhaust valves to not close fully. When the exhaust valves don’t fully close it causes blow-by that enters the combustion chamber which then burns up the valves.

Therefore, the valves need to be frequently adjusted to maintain proper clearance and prevent burnt valves. Burnt valves will require the replacement of the valves which is a rather expensive repair. So while this isn’t a common problem if you have your valves adjusted, it is a common problem for those that don’t have them adjusted ever.

Valve adjustment requires a special tool and is a complex job so we recommend having them adjusted at a reputable shop. There are a few signs that the valves need adjusting but they aren’t always present or easy to pick-up on which is why it’s important to have them checked frequently.

Signs the Valves Need Adjusting

• Ticking noise at idle
• Lack of power, engine doesn’t hit redline
• Misfires (caused by blow-by in the combustion chamber)
• Exhaust smoke
• Increased fuel consumption

5. Balance Shaft Bearing Problems

As we mentioned earlier, the 3RZ uses two chain-driven balance shafts. Balance shafts are mostly used in inline-4 engines. The system has two shafts and each shaft has weights on it. The shafts then rotate in opposite directions and rotate at twice the speed of the engine. How they work is rather technical in nature but essentially the force caused by the rotation of the shafts cancels out vibration produced by the engine.

The balance shaft uses bearings which help reduce friction and ensure the balance shafts rotate properly. Bearing failure appears to be more common in 2001-2009 3RZ-FE’s sold in Venezuela. While this doesn’t appear to be as common in US markets there are a number of cases of this occurring. It is at least common enough for some companies manufacture a balance shaft removal kit.

Balance Shaft Failure Symptoms

• Lots of engine vibration
• Rough idling
• Overall rough running
• Rattling under acceleration
• Misfires or stalls

Balance shaft repair is quite expensive so a lot of people with this problem opt to just remove the balance shafts. Again, we don’t think this is a very common problem but it has been recorded enough for us to mention it considering the cost of the repair.

Toyota 3RZ-FE Reliability

Is the 3RZ-FE engine reliability? Yes, and it’s very reliable to that extent. Major engine components like the block, cylinder heads, and internals are extremely durable and likely won’t ever give you any serious problems. When you put forged components into an engine making 150hp you are pretty much guaranteed to have fantastic reliability.

The one caveat to my above statement is the valves. Valve failure isn’t a common problem but it can become a problem if valve adjustments aren’t made frequently. Be sure to check valve clearance and seating every 25,000 miles and adjust it as necessary.

Additionally, the 3RZ-FE timing chain problems are less of problems and more of maintenance items. Same goes for bad water pumps. The serpentine belt is probably going to squeak every 100,000 miles but it’s a $10 part so there is no heartache there. The last problem, balance shaft bearing failure, isn’t common enough to give us any concern over the long term reliability of the 3RZ.

The 3RZ-FE engine should easily last 300,000 miles. And it can usually reach those levels with very minimal amounts of maintenance.