2014 Flex Workshop Manual

SECTION 303-01A: Engine — 3.5L Ti-VCT	2014 Flex Workshop Manual
DESCRIPTION AND OPERATION	Procedure revision date: 05/02/2013

Engine

Overview

The 3.5L (4V) is a V-6 engine with the following features:

Dual overhead camshafts
Four valves per cylinder
Sequential Multi-Port Fuel Injection (SFI)
Composite upper and lower intake manifolds
Aluminum cylinder heads
An aluminum, 60-degree V-cylinder block
Timing chain driven coolant pump
Twin independent Variable Camshaft Timing (VCT) system
An electronic ignition system with 6 ignition coils

Engine Identification

For quick identification, refer to the safety certification decal.

The decal is located on the LH front door lock face panel.

Engine Code Information Label

Item	Description
1	Engine part number
2	Engine plant (Cleveland)
3	Engine displacement
4	Engine configuration
5	Twin independent VCT
6	Bar code
7	Bar code
8	Running number
9	Engine build date (DDMMYY)
19	Plant shift line
11	Derivative code

Engine Cylinder Identification

System Operation

Engine Oil Flow Illustration

Item	Part Number	Description
1	6600	Oil pump
2	6622	Oil pump screen and pickup tube
3	6K868	Piston oil cool valve
4	6303	Crankshaft
5	6C634	Engine main bearing cap support
6	6675	Oil pan
7	6714	Oil filter
8	6881	Oil filter adapter (without oil cooler)
9	9278	Engine Oil Pressure (EOP) sensor
10	6881	Oil filter adapter (with oil cooler)
11	6A642	Oil cooler
12	6049	LH cylinder head
13	6250	Exhaust camshaft
14	6250	Intake camshaft
15	6A258	LH camshaft cap
16	6K602	LH valve train oil feed tube
17	6K254	LH secondary timing chain tensioner
18	6B280	LH camshaft mega cap
19	6M280	LH intake and exhaust camshaft VCT oil control solenoid
20	6C525	LH exhaust camshaft VCT
21	6C524	LH intake camshaft VCT
22	6A280	RH camshaft cap
23	6K602	RH valve train oil feed tube
24	6C270	RH secondary timing chain tensioner
25	6B280	RH camshaft mega cap
26	6M280	RH intake and exhaust camshaft VCT oil control solenoid
27	6C525	RH exhaust camshaft VCT
28	6C524	RH intake camshaft VCT
29	6049	RH cylinder head
30	6010	Cylinder head
31	6K254	Primary timing chain tensioner

Lubrication System

The engine lubrication system is of the force-feed type in which oil is supplied under full pressure to the crankshaft, connecting rod bearings, timing chain tensioners, piston oil cooling jets and VCT solenoids. The flow of oil to the valve tappets and valve train is controlled by a restricting orifice located in the cylinder head, front camshaft cap.

Oil Pump

The lubrication system is designed to provide optimum oil flow to critical components of the engine through its entire operating range.

The heart of the system is a positive displacement internal gear oil pump.

Generically, this design is known as a gerotor pump, which operates as follows:

The oil pump is mounted on the front face of the cylinder block.
The inner rotor is piloted on the crankshaft post and is driven through flats on the crankshaft.
System pressure is limited by an integral, internally-vented relief valve which directs the bypassed oil back to the inlet side of the oil pump.
Oil pump displacement has been selected to provide adequate volume to make sure of correct oil pressure both at hot idle and maximum speed.
The relief valve calibration protects the system from excessive pressure during high-viscosity conditions.
The relief valve is designed to provide adequate connecting rod bearing lubrication under high temperature and high-speed conditions.

Valve Train

The valve train uses Direct Acting Mechanical Buckets (DAMB). The camshaft lobes are positioned directly above mechanical buckets which are positioned on top of the valves.

Twin Independent VCT System

The twin independent VCT system allows variable control of intake valve closing which optimizes combustion at full load providing improved power and low speed torque (broadening the torque curve) which enables variable valve overlap which provides better fuel economy and emissions and provides optimized cold start operation with improved exhaust emissions.