Toyota Diesel OEM 2L 2L-T 2L-TE 3L 5L 82°C Thermostat HiAce Hilux Surf Land Cruiser Prado 16340-54040

Product Overview

Genuine OEM Toyota Thermostat compatible with 1984-2006 Toyota Hilux, Land Cruiser Prado, 4Runner, Hiace, Dyna, and Fortuner models with 2L, 2L-T, 2L-TE, 3L, and 5L diesel engines. This critical cooling system component regulates engine operating temperature and ensures optimal performance in Toyota's legendary L-series diesel engines. This OEM thermostat features an opening temperature of 82°C (180°F), providing superior temperature control compared to higher-rated alternatives for engines prone to overheating.

OEM Part Number(s):

• 16340-54040 (current - 82°C/180°F)
• 90916-03072 (superseded - 88°C/190°F factory spec)
• 90916-03099 (related application)
• 90916-03043 (previous)

 

Key Features & Benefits

• Cooler Operating Temperature: 82°C opening temperature helps prevent overheating in 2L, 2L-T, and 3L engines known for running hot
• Quality Construction: Metal construction with precision-engineered wax element for reliable temperature control
• Performance: Maintains optimal engine temperature for improved efficiency and reduced risk of cylinder head cracking
• Value: Prevents costly overheating damage while maintaining proper diesel engine operating parameters

 

Technical Specifications

Part Type: Engine Coolant Thermostat
Material: Metal construction with wax pellet actuator
Opening Temperature: 82°C (180°F)
Fully Open Temperature: 95°C (203°F)
Engine Compatibility: 2L (2.4L), 2L-T (2.4L Turbo), 2L-TE (2.4L Turbo EFI), 3L (2.8L), 5L (3.0L)

Fitment

Year Range	Toyota Model	Engine Options
1984-2004	Hilux / Pickup	2L, 2L-T, 2L-TE, 3L, 5L diesel engines
1988-2004	Land Cruiser Prado (70, 90 Series)	2L-T, 2L-TE, 3L, 5L diesel engines
1988-2002	4Runner / Hilux Surf	2L, 2L-T, 2L-TE, 3L diesel engines
1995-2006	Hiace (H100, H200)	2L, 2L-T, 3L, 5L diesel engines
1995-2004	Granvia / Grand Hiace	3L diesel engine
1995-2006	Dyna / ToyoAce	2L, 3L, 5L diesel engines (select models)

Important: This thermostat requires a separate gasket for installation. Two gasket types are available depending on your specific application: metal gasket (16341-54040, 16341-54030, 16341-54011) or rubber o-ring gasket (16341-35010). Verify your engine configuration and provide VIN information to ensure proper gasket selection. The 5L and 5L-E engines may utilize different glow plugs and some cooling system components; verify compatibility before purchase.

Installation & Maintenance

Installation Difficulty: Beginner to Intermediate
Tools Required: Socket set, drain pan, coolant, new gasket or o-ring, torque wrench
Professional Installation: Optional - DIY-friendly for mechanically inclined owners

Maintenance Tips:

• Always replace the thermostat gasket or o-ring during installation to prevent coolant leaks
• Drain and refill the cooling system with a fresh coolant mixture appropriate for your climate
• Bleed air from the cooling system after installation to avoid hot spots and ensure proper operation
• Monitor the engine temperature gauge closely during the first drive cycle to verify proper thermostat operation

 

Frequently Asked Questions

Q: What's included in the package?
A: This listing includes the thermostat only. The required gasket or O-ring seal is sold separately and must be ordered according to your specific engine application. Use your VIN to ensure the correct gasket selection.

Q: Why choose 82°C instead of the factory 88°C thermostat?
A: The 2L-T, 2L-TE, and 3L engines are known to run hot, particularly under load or in warm climates. The 82°C thermostat provides earlier cooling system activation, reducing the risk of overheating and cylinder head cracking, which are common issues with these engines. Many diesel specialists recommend the cooler thermostat for improved reliability.

Q: How difficult is installation?
A: Installation is straightforward for mechanically inclined owners. The thermostat housing is typically accessible from the top of the engine. Drain coolant, remove housing bolts, replace thermostat and gasket, refill and bleed system. Allow 1-2 hours for careful work, including proper bleeding procedures.

Q: Will this fit both early and late L-series engines?
A: This thermostat is designed for late-model 2L-II, 2L-T, 2L-TE, 3L, and 5L engines from approximately 1988 onward. Earlier 2L engines may use different specifications. The gasket type also varies between applications - metal gasket for most, rubber o-ring for some. Verify your specific engine configuration.

Common Symptoms of Thermostat Failure

• Engine overheating under load or in traffic conditions
• Engine takes excessive time to reach normal operating temperature
• Temperature gauge fluctuating between normal and hot readings
• Poor cabin heater performance indicating restricted coolant flow
• Coolant leaking from thermostat housing due to failed gasket or seal

 

Why Replace Your Toyota Diesel Thermostat

Critical Protection for L-Series Diesel Engines: Toyota's L-series diesel engines, including the 2L, 2L-T, 2L-TE, and 3L, are renowned for their reliability and longevity; however, they have a well-documented tendency to run hot. This characteristic makes proper cooling system maintenance absolutely critical for preventing the cylinder head cracking issues that have plagued these engines.

The factory 88°C thermostat specification was designed for moderate operating conditions, but real-world experience from diesel specialists worldwide demonstrates that the cooler 82°C thermostat provides crucial additional protection. By allowing the cooling system to activate earlier, this thermostat reduces peak operating temperatures and provides extra margin against overheating - particularly important when towing, operating in hot climates, or navigating steep terrain.

This is not merely a preventive measure - cylinder head replacement on these engines is an expensive and labor-intensive repair that can exceed the value of the vehicle. The 2L-TE and 3L engines are interference designs with bucket-and-shim valve adjustment systems, meaning any overheating incident that causes head gasket failure or warpage leads to catastrophic damage if not caught immediately.

Investing in genuine OEM quality with the proper temperature rating is the single most cost-effective insurance policy for your Toyota diesel engine. Combined with regular cooling system maintenance, including fresh coolant, proper bleeding procedures, and radiator cap replacement, this thermostat will help ensure your L-series diesel provides the legendary Toyota reliability these engines are capable of.

Don't wait for overheating symptoms to appear - replace your thermostat as preventive maintenance and protect your investment in Toyota's legendary diesel platform.