Template:More citations needed Template:Infobox automobile engine

The Toyota MZ engine family is a piston V6 engine series. It was Toyota's second V6 engine after the VZ engine family, of which the MZ series succeeded it.

The MZ family is a lightweight V6 engine of an all-aluminium design, using lightweight parts than the previous heavy-duty VZ block engines in an effort to lower production costs and decrease engine and reciprocating weight without sacrificing reliability. Toyota sought to enhance the drivability pattern of the engine (over the 3VZ-FE) at exactly 3000 rpm, since that was the typical engine speed for motors cruising on the highway. The result was less cylinder distortion coupled with the decreased weight of rotating assemblies, smoother operation at that engine speed, and increased engine efficiency.Template:Citation needed

The MZ series has an aluminium engine block and aluminium alloy DOHC cylinder heads. The cylinders are lined with cast iron, and is of a closed deck design (no open space between the bores). The engine is a 60 degree V6 design. It uses multi-port fuel injection (MFI), four valves per cylinder, a one-piece cast camshaft and a cast aluminium intake manifold.

This engine has been phased out in most markets, replaced by variants of the then-new GR series.

1MZ-FEEdit

File:1999Camry1mzfev6engine.jpg
Toyota 1MZ-FE engine without VVT-i

The 1MZ-FE is a Template:Convert dual overhead cam (DOHC) V6 engine, replacing the 3VZ-FE as the standard 3.0 L V6 engine in North America and later worldwide. Bore and stroke is Template:Convert. Output is Template:Convert at 5200–5400 rpm with Template:Convert of torque at 4400 rpm. Horsepower ratings dropped after the Society of Automotive Engineers (SAE) implemented a new power measurement system for vehicle engines; Toyota engines rated on 87 octane dropped the most, compared to the same engines used by Lexus rated on 91 octane. It has bucket tappets and was designed for good fuel economy of Template:Convert city and Template:Convert highway without an overall performance trade-off.

Toyota Racing Development offered a factory supported bolt-on supercharger kit for the MY1997–2000 Camry, MY1998–2000 Sienna and MY1999–2000 Solara in North America. Power output was bumped to Template:Convert and Template:Convert of torque.

The 1MZ-FE was on Ward's 10 Best Engines list for 1996.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Applications:

Beginning in 1998, VVT-i was added. This increased the output to Template:Convert at 5800 rpm and Template:Convert of torque at 4400 rpm. It was used on later models of the Avalon, Sienna and Camry. Early versions of the 1MZ-FE with VVT-i used a dual throttle body while later versions used a drive by wire system (or electronic throttle control). It also contains an EGR block off plate on the exhaust manifolds.

Applications:

Excessive oil consumption issuesEdit

These engines are notorious for excess oil consumption, otherwise known as "oil gelling"<ref name="1mzlawsuit" /> or "engine sludge".<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name="valvolinesludge" /> This is caused by several factors, including problems with the engine's PCV system, worn-off parts, or a bad or leaking valve cover gasket. This allowed oil to leak into the engine bay, with symptoms ranging from blue-grey smoke, bad spark plugs and sludge buildup in cylinder bank 2, to low compression on the second cylinder. This issue is widespread in many 1MZ engines produced, especially in later models, and as such affected many vehicles that used this engine in their configurations. It is very important to the life of these engines that oil changes should be done on a regular basis.<ref name="valvolinesludge">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> A class action lawsuit was filed because of this problem.<ref name="1mzlawsuit">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> This particular issue remains a significant concern for 1MZ engines of that era.

2MZ-FEEdit

File:Engine-2mzfe.jpg
Toyota 2MZ-FE engine

The 2MZ-FE is a Template:Convert V6 engine, replacing the 4VZ-FE as the worldwide 2.5 L V6 engine. Bore and stroke is Template:Convert. Output is Template:Convert at 6000 rpm with torque of Template:Convert at 4600 rpm.

Applications:

3MZ-FEEdit

File:3MZ-FE in 2004 Lexus ES330.jpg
3MZ-FE in a 2004 Lexus ES330

The 3MZ-FE is a Template:Convert version. Bore and stroke is Template:Convert. Output is Template:Convert with Template:Convert of torque in the Camry and Template:Convert with Template:Convert of torque in the Sienna and Highlander. It also features VVT-i, ETCS-i (Electronic Throttle Control System — intelligent/DBW), PA6 plastic intake, and increased throttle body diameter over the 1MZ. The 3MZ uses a new flat-type knock sensor, which is a departure from the typical resonator type knock sensor used on the previous MZs. Previous MZs had poor knock control, or perhaps oversensitivity when detecting knock, and power loss up to Template:Convert may be realized due to erratic ignition timing when using an octane lower than 91. The new flat-type knock sensor is a completely different design and detects more frequencies than the traditional resonator type. This provides the ECU with more accurate data. A bolt goes through the center of the knock sensor, which then mates the sensor to the block on each bank.

Applications:

See alsoEdit

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ReferencesEdit

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