4 Common Toyota Highlander Engine Problems and Fixes

The V6 Toyota Highlander engine has been manufactured since 2000. It features 3 different powertrain options: a 3.5-liter V6 engine, a 2.5-liter 4-cylinder engine with a generator, and a 2.4-liter 4-cylinder turbo engine.

Each Highlander engine is connected to an 8-speed automatic transmission. Highlander’s engines have had some issues over the years. I have discussed those issues in depth in this article.

There are four common Toyota Highlander engine problems: engine sludge, low oil pressure, leaking oil, and head gasket failure. I have discussed these problems and their solutions in detail.

Problem 1: Engine Sludge

Engine Sludge is a jelly-like substance that accumulates and builds up in the engine. It contaminates the engine oil.


Driving on dusty roads, using low-viscosity engine oil, or not changing the engine oil frequently can all contribute to engine sludge buildup.

Sludge can form when the coolant gets into the engine oil through a gasket leak or when the engine overheats.

4 Symptoms of engine sludge:

  1. You will see the engine light on.
  2. The engine will knock as movement is hindered.
  3. The engine will overheat.
  4. Engine performance, such as power and fuel economy, will decrease.


You can use engine flush. It is a chemical that, when mixed with engine oil, also washes away engine sludge while draining old engine oil.

First, add the engine flush with the old engine oil.

Then keep the engine on for 10–20 minutes, and do not drive the car at that time.

By doing this, the chemical will mix well with the engine oil, and the sludge from the engine oil will also mix.

Then, turn off the engine and change the oil filter.

In this way, the engine sludge will be removed.

Problem 2: Low Oil Pressure

Insufficient engine lubrication and cooling moving parts are the main causes of low oil pressure.

It can cause the parts to grind against each other and wear out prematurely.


If your car is low on engine oil, the oil pressure is low.

Even if the engine oil leaks, its quantity may decrease.

Engine oil pressure can be low if the oil pump is damaged or the oil filter is blocked.

Low oil pressure also occurs when the viscosity of engine oil is low.

In this case, there may be the new oil, or the viscosity of the oil may decrease even at high engine temperatures.

After a period, the loosening of moving parts due to engine wear can cause oil leaks and low engine oil pressure.

Similarly, the pressure sensor may be damaged with time.

4 Symptoms of low oil pressure are:

  1. You will see the oil pressure light on.
  2. The engine will knock due to a lack of proper lubricant.
  3. The engine will overheat.
  4. Engine cylinders will misfire.


First, check the engine oil level and refill if necessary.

Then inspect the oil pump and oil filter; if damaged or clogged, repair them.

Observe engine oil viscosity and change it if you notice thin oil.

Screw and tighten bolts related to the engine.

Replace the pressure sensor if it is damaged.

Thus, you can solve low oil pressure.

Problem 3: Leaking Oil

Leaking oil is a condition where engine oil drains out through a leak.

This can damage the engine and cause a fire hazard.


Damaged gaskets or cracked oil pans can cause engine oil leaks.

A loose or damaged oil filter can cause oil leaks.

An overheated engine can melt gaskets and cause oil leaks.

Driving in harsh weather affects the engine and gaskets and causes oil leaks.

6 symptoms of leaking oil

  1. You will see oil deposits on the underside of your car.
  2. The engine oil level will drop quickly.
  3. The engine oil light will come on.
  4. Bluish-gray smoke will be emitted.
  5. You will smell burned oil.
  6. The engine will knock and overheat.


You should check the engine’s oil pan, gasket, and oil filter. Change them if necessary.

Problem 4: Head Gasket Failure

Head gasket failure occurs when the thin metal covering between the engine block and cylinder head breaks or becomes perforated.

Coolant and engine oil will mix and adversely affect the engine if it is damaged.


The main cause is the head gasket melting when the engine overheats.

When the coolant level drops, the head gasket is stressed and damaged.

Debris entering the engine can also damage the head gasket.

Over time, gaskets get damaged.

4 symptoms of head gasket failure are:

  1. The engine’s exhaust system will emit white smoke.
  2. You will see milky oil in the engine.
  3. Engine cylinders may misfire.
  4. The engine may knock and overheat.


You can use a head gasket sealer immediately. But the permanent solution is replacing the gasket.

Toyota Highlander Engine Repair Cost

How many dollars would it cost to repair the Toyota Highlander engine? For your convenience, I have made a chart of possible costs.



Engine Flush


Oil Pump


Oil Filter




Oil Pan


Pressure Sensor


Head Gasket


In addition, the mechanic will charge you between $100 and $300, depending on your region.

How to Prevent Toyota Highlander Engine Problems in the Future?

I have mentioned some precautions to maintain your car’s engine health in the future.

  • Change engine oil every 4000 miles (6437 km).
  • Use a high-viscosity, good-quality engine oil.
  • Don’t let your engine overheat.
  • Avoid driving in rough weather, especially in dusty areas.
  • Check the oil level every 6500 miles (10,460 km).
  • Regularly clean the engine.
  • Use a high-quality fuel additive.


How fuel-efficient is Toyota Highlander?

The Toyota Highlander’s engine and motor determine its fuel efficiency.

The 3.5-liter V6 engine’s fuel economy is 21/29 mpg city/highway.

The hybrid variant achieves 29/36 mpg city/highway.

Does the Toyota Highlander have a turbo engine?

Yes, the Toyota Highlander has a turbo engine.

It has a 2.4-liter engine and gets 21/29 mpg city/highway.

It is more fuel-efficient than the main engine.

Why did Toyota change the engine in the Highlander?

Toyota modified the Highlander’s engine to increase power and fuel economy.

The latest engine is more effective and potent than the old one.

Does the Toyota Highlander have a good engine?

The Toyota Highlander indeed has a strong engine.

The engine is robust and trustworthy. It has decent fuel efficiency as well.

How long can a Toyota Highlander run?

A Toyota Highlander can usually run for 200,000 miles (321,868 km) without any issues.

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