Un guide critique: FAW Ensemble collecteur d'échappement et collecteur d'admission pour tracteur CA4251P66K24T1A3E5

Welcome to this advanced technical guide for the Ensemble collecteur d'échappement et collecteur d'admission FAW, a critical system for the FAW Jiefang CA4251P66K24T1A3E5 6×4 tracteur semi-remorque diesel. This assembly is responsible for the engine’s entire “respiration” processus, from routing clean air in to expelling hot exhaust gases out.

Ce Ensemble collecteur d'échappement et collecteur d'admission FAW 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, gestionnaires de flotte, et spécialistes des pièces détachées. Nous déconstruirons l'ensemble Ensemble collecteur d'échappement et collecteur d'admission FAW, including all gaskets, heat shields, attaches, and connecting pipes, breaking it down to the smallest serviceable unit to ensure accurate diagnostics and repairs.

Composant principal: The Two-Part Exhaust Manifold

Le coeur du “échappement” côté du Ensemble collecteur d'échappement et collecteur d'admission FAW is a two-piece manifold. The parts list calls for two units of ‘Exhaust Manifold (je)’ (1008041-81D) and one unit of ‘Exhaust Manifold (II)’ (1008042-91W). For a six-cylinder engine, this indicates a “diviser” 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, est essentiel pour gérer la dilatation thermique. 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, fissure, 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.

Gestion de l'air: Tuyau de connexion d'admission (1008023-81D)

Le “admission” partie de la Ensemble collecteur d'échappement et collecteur d'admission FAW 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 “côté froid” du moteur. 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, non répertorié) est critique. 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, consommation de carburant élevée, and black smoke from the exhaust. Ensuring this pipe is secure is a key diagnostic step for any low-power complaint related to the Ensemble collecteur d'échappement et collecteur d'admission FAW.

Étanchéité critique: Joints (1008044-81D) and Rings (1008043-29D)

The single most important serviceable part of the Ensemble collecteur d'échappement et collecteur d'admission FAW is its sealing system. The parts list calls for six units of ‘Gasket – tuyau d'échappement’ (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) joints, 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” ou “puffing” son, 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. Ce sont des températures élevées “doughnut” joints, 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 Ensemble collecteur d'échappement et collecteur d'admission FAW.

High-Temp Fasteners: Crampons, Boulons, and Sleeves

Sécuriser le Ensemble collecteur d'échappement et collecteur d'admission FAW 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 “froid” 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.

Critique, 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 Ensemble collecteur d'échappement et collecteur d'admission FAW‘s robust design.

Bouclier thermique (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, conduites de carburant, or the plastic cylinder head cover. A missing heat shield will invariably lead to other, seemingly unrelated failures.

The ‘Support assembly – tuyau de connexion’ (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 Ensemble collecteur d'échappement et collecteur d'admission FAW.

FAW Exhaust Manifold And Intake Manifold Assembly Parts List

Le tableau suivant fournit l'intégralité, detailed breakdown of all components identified in the ‘Exhaust Manifold and Intake Connecting Pipe Assembly’ schéma du tracteur FAW CA4251P66K24T1A3E5.

Spécifications techniques et contexte d'assemblage

Les spécifications pour le Ensemble collecteur d'échappement et collecteur d'admission FAW are defined by its dual role in handling both pressurized, cold intake air and superheated, pre-turbo exhaust gas.