Ford 3.5L Duratec/Ti-VCT Engine (Specs, Reliability & Issues)
Updated: May 2
The Duratec 35 is a 3.5-liter V6 natural aspirated gasoline engine used in the Ford Cyclone range. In 2006, the engine was initially installed in the Ford Edge and Lincoln MKX. The Ford F-150 received the 3.5L Ti-VCT engine in 2015, replacing the 3.7-liter Cyclone series 3.7L Ti-VCT V6 engine.
From 2007 to 2016, Mazda used this Ford 3.5l V6 engine in the Mazda CX-9.
Design
The Cyclone 3.5L engine is made completely of aluminium. It has a cast aluminium alloy open-deck cylinder block with cast-in liners that is completely floating at the top. It has the same bore and stroke combination as the popular 3.5L EcoBoost, other from the basic structure.
Like the 3.7L V6, the 3.5L V6 features a forged crankshaft (4130 alloy steel) that is held in place by 6-bolt billet steel main caps. The connecting rods are made of aluminium and the pistons have a low friction coefficient.
Cast-in oil squirters within the engine spray engine oil on the bottom ends of pistons, giving extra cooling. The Duratec 35 has aluminium cylinder heads with four valves per cylinder. Mechanical buckets that are actuated directly regulate the valves (DAMB).
The engine has chain-driven double overhead camshafts (DOHC) with variable intake timing (iVCT) or variable intake and exhaust timing (Ti-VCT - twin-independent variable cam timing, implemented in 2011).
A single roller timing chain drives the intake camshafts, while smaller chains drive the exhaust camshafts. In 2011, a silent form of timing chain was created to replace a single roller timing chain (small chains remain the same).
Previously, a water pump was located at the rear of the engine and was driven by a rubber belt from the intake camshaft pulley. A front-mounted chain-driven water pump is concealed beneath a front-end engine cover on Cyclone engines.
Coil-on-plug ignition is used, and a sequential multi-port fuel injection system is controlled electronically. Plastic makes up the intake manifold, which is divided into two sections: a lower intake and an upper intake. The exhaust manifolds are made of cast iron.
The 3.5L V6 engine was listed in Ward's "10 Best Engines" list. It has been used in a range of Ford and Lincoln vehicles since 2007.
Ford continues to offer this engine for many of them, but it has also manufactured a new Cyclone version - a normally aspirated 3.3L Ti-VCT V6 direct and port injection engine that was introduced in 2017 to replace the NA 3.5L V6s in the Ford F150.
Specs
Manufacturer: Lima Engine Plant, Lima, Ohio, the USA
Production years: 2006-present
Cylinder block material: Aluminium
Cylinder head material: Aluminium
Fuel type: Gasoline
Fuel system: Sequential multi-port fuel injection
Configuration: V
Number of cylinders: 6
Valves per cylinder: 4
Valvetrain layout: DOHC
Bore: 92.5 mm (3.64 in)
Stroke: 86.6 mm (3.41 in)
Displacement: 3,496 cc (213.3 cu in)
Type: Four-stroke, naturally aspirated
Compression Ratio: 10.8:1
Power: 262-290 hp (195-216 kW) at 6,250-6,500 rpm
Torque: 248-255 lb-ft (336-346 Nm) at 4,000-4,250 rpm
Firing order: 1-4-2-5-3-6
Engine oil weight: SAE 5W-30
Engine oil capacity: 5.7 litres (6.0 qt) - with oil filter
Oil change interval: 10,000 miles (15,000 km) or 12 months
Applications: Ford F-150, Ford Edge, Ford Flex, Ford Taurus, Ford Explorer, Ford Fusion Sport, Ford Taurus X, Lincoln MKX, Lincoln MKZ, Mercury Sable, Mazda CX-9
Problems & Reliability
The water pump failure in Ford's 3.5L V6 engines is a major worry. As previously noted, the water pump on the 3.5 is internal and is driven by the timing chain. There are two major faults with this concept.
For starters, a malfunctioning water pump might leak for a long time and go undetected until the coolant level has fallen significantly, resulting in overheating. Second, the leaking coolant reacts with the engine oil, generating an emulsion that dries out all internal components reducing the effectiveness of the oil.
The pulleys, front cover, and timing chains must all be removed before the water pump can be removed. As a result, replacing it is a labor-intensive and hence expensive task.
The Duratec 35/3.5L Ti-VCT V6 engine, on the other hand, is a perfectly suitable engine for light duty applications, with plenty of power and good gas mileage. The engine is expected to last 200,000 miles (300,000 km).
