A Critical Guide: FAW Exhaust Manifold And Intake Manifold Assembly for the CA4251P66K24T1A3E5 Tractor

Welcome to this advanced technical guide for the FAW Exhaust Manifold And Intake Manifold Assembly, a critical system for the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is responsible for the engine’s entire “breathing” process, from routing clean air in to expelling hot exhaust gases out.

This FAW Exhaust Manifold And Intake Manifold Assembly is a high-performance system designed to withstand extreme temperatures and pressures. It manages the flow of pressurized air from the turbocharger into the engine and simultaneously collects superheated exhaust gases to drive the turbo.

This guide is an essential resource for engine technicians, fleet managers, and parts specialists. We will deconstruct the entire FAW Exhaust Manifold And Intake Manifold Assembly, including all gaskets, heat shields, fasteners, and connecting pipes, breaking it down to the smallest serviceable unit to ensure accurate diagnostics and repairs.

Core Component: The Two-Part Exhaust Manifold

The heart of the “exhaust” side of the FAW Exhaust Manifold And Intake Manifold Assembly is a two-piece manifold. The parts list calls for two units of ‘Exhaust Manifold (I)’ (1008041-81D) and one unit of ‘Exhaust Manifold (II)’ (1008042-91W). For a six-cylinder engine, this indicates a “split” manifold design. This is a common and critical engineering feature on heavy-duty diesel engines.

This design, likely splitting the manifold into two three-cylinder sections, is essential for managing thermal expansion. A cast-iron manifold can reach temperatures exceeding 700°C (1300°F). A single, long manifold for six cylinders would expand and contract so much that it would warp, crack, or shear its own mounting bolts.

By splitting the manifold, each section can expand and contract independently, dramatically reducing metal fatigue and stress. These sections are typically joined by a flexible joint or a slip-fit connection (using the ‘Exhaust pipe sealing ring’ 1008043-29D) before they enter the turbocharger. The material is a high-silicon, ductile cast iron, designed to withstand thousands of extreme heat cycles without failing.

Air Management: Intake Connecting Pipe (1008023-81D)

The “intake” portion of the FAW Exhaust Manifold And Intake Manifold Assembly is represented by the ‘Intake Connecting Pipe’ (1008023-81D). This single component is the main artery for all the clean, pressurized air that enters the engine.

This pipe is located on the “cold side” of the engine. It is *not* the intake manifold itself, but the rigid pipe that connects the intercooler’s outlet to the engine’s intake plenum. It is typically made of cast aluminum or high-strength molded composite to be lightweight and to help keep the intake air charge cool.

The integrity of this pipe and its seals (often large O-rings, not listed) is critical. Any leak in this pipe, known as a “boost leak,” will cause the turbocharger to work harder to produce the same pressure, leading to a severe loss of power, high fuel consumption, and black smoke from the exhaust. Ensuring this pipe is secure is a key diagnostic step for any low-power complaint related to the FAW Exhaust Manifold And Intake Manifold Assembly.

Critical Sealing: Gaskets (1008044-81D) and Rings (1008043-29D)

The single most important serviceable part of the FAW Exhaust Manifold And Intake Manifold Assembly is its sealing system. The parts list calls for six units of ‘Gasket – exhaust pipe’ (1008044-81D). This corresponds to the six exhaust ports on the cylinder head, one for each cylinder.

These are not standard paper gaskets. They must be Multi-Layer Steel (MLS) gaskets, composed of multiple embossed layers of stainless steel. These layers are designed to act like springs, compressing slightly when tightened. This spring-like action allows them to maintain a positive seal even as the cast-iron manifold and aluminum or iron head expand and contract at different rates.

A failure of one of these gaskets is a common issue on high-mileage engines. The primary symptom is a loud “ticking” or “puffing” sound, especially when the engine is cold (before the metal expands). This leak is not just noisy; it is dangerous. It can vent hot, toxic exhaust fumes into the engine bay, and by allowing fresh air to be pulled *into* the manifold, it can disrupt the air-fuel ratio and cause the turbocharger to spin at an incorrect speed.

The list also specifies four ‘Exhaust pipe sealing ring’ (1008043-29D). These are not for the head-to-manifold connection. These are high-temperature “doughnut” gaskets, often made of graphite composite or wire mesh. They are used to seal the slip-joints between the two manifold halves and at the final connection flange that leads to the turbocharger. They are designed to allow for slight movement and misalignment while still preventing any leaks of the high-pressure, pre-turbo exhaust gas. Replacing all six gaskets and all four rings is mandatory when servicing the FAW Exhaust Manifold And Intake Manifold Assembly.

High-Temp Fasteners: Studs, Bolts, and Sleeves

Securing the FAW Exhaust Manifold And Intake Manifold Assembly requires a complex assortment of specialized, high-temperature fasteners. The list includes ‘Exhaust pipe long fastening bolt’ (1008051-2000), ‘Exhaust pipe fastening bolt’ (1008049-53D), and an ‘Exhaust pipe stud’ (1008049-2000) with its ‘Hex head flange lock nut’ (CQ32610).

This mix of studs and bolts is intentional. Studs are often preferred for high-heat applications because they are threaded into the “cold” cylinder head only once. This prevents wear and tear on the delicate threads in the head. The manifold then slides onto the studs, and a nut is used to apply clamping force. This is a more reliable and serviceable design.

Critically, the list also includes two types of sleeves: ‘Exhaust pipe bolt sleeve’ (1008048-2000) and ‘Exhaust manifold long bolt sleeve’ (1008048-29D). These are not optional. These sleeves act as precision spacers, ensuring the bolt or stud can apply the correct clamping force. They also act as a heat shield for the bolt, preventing the bolt itself from getting as hot as the manifold. This is vital for preventing the bolts from stretching, loosening, or snapping, which is a common failure point in improperly serviced exhaust systems. These sleeves are a key part of the Ford FAW Exhaust Manifold And Intake Manifold Assembly‘s robust design.

Heat Shield (1008061-81D) and Support (1203070-2000)

The final two components are for heat management and structural support. The ‘Exhaust pipe cover’ (1008061-81D) is a stamped metal heat shield. Its sole function is to sit on top of the manifold, creating a barrier of air. This barrier prevents the manifold’s intense radiant heat from cooking nearby components like wiring harnesses, fuel lines, or the plastic cylinder head cover. A missing heat shield will invariably lead to other, seemingly unrelated failures.

The ‘Support assembly – connecting pipe’ (1203070-2000) is a structural brace. The heavy turbocharger and exhaust piping cannot be left to hang solely off the manifold; the vibration and weight would crack the manifold in short order. This support bracket bolts to a rigid point on the engine block and to the connecting pipe or turbo, providing the essential support needed to handle the vibration and shock loads of a heavy-duty truck. This brace is essential to the longevity of the entire FAW Exhaust Manifold And Intake Manifold Assembly.

FAW Exhaust Manifold And Intake Manifold Assembly Parts List

The following table provides the complete, detailed breakdown of all components identified in the ‘Exhaust Manifold and Intake Connecting Pipe Assembly’ diagram for the FAW CA4251P66K24T1A3E5 tractor.

Technical Specifications and Assembly Context

The specifications for the FAW Exhaust Manifold And Intake Manifold Assembly are defined by its dual role in handling both pressurized, cold intake air and superheated, pre-turbo exhaust gas.