Fig. 5.24. Catalytic collector: 1 – control sensors of oxygen concentration in exhaust gases; 2 – diagnostic sensors for oxygen concentration in exhaust gases
Exhaust gases are discharged from the engine through the exhaust manifold (Fig. 5.24) (exhaust manifold combined with neutralizers), additional 4 (Fig. 5.25) and main 2 mufflers.
Fig. 5.25. Exhaust system components located on the body base: 1 – exhaust pipe; 2 – main muffler; 3 – intermediate pipe; 4 – additional muffler
On the catalytic converter there are two main (control) oxygen concentration sensors 1 (see Fig. 5.24) and (after the neutralizers) two diagnostic sensors 2.
A metal-reinforced sealing gasket is installed between the flanges of the cylinder head and the exhaust manifold.
The inlet pipe of the additional muffler 4 (see Fig. 5.25) is connected to the exhaust manifold, and its outlet pipe is connected to the main muffler 2. The connections of the inlet and intermediate 3 pipes with the additional muffler, as well as the intermediate and exhaust 1 pipes with the main muffler are welded and therefore non-separable. The flange connection of the inlet pipe of the additional muffler and the exhaust manifold is sealed with a metal-reinforced gasket. Thus, all elements of the exhaust system located on the base of the body are made as a single unit and cannot be dismantled separately without the use of a metal-cutting tool. However, spare parts are supplied as separate elements of the system, which are connected by welding or special couplings during installation on the vehicle.
The system elements are suspended from the body on five rubber cushions. Moreover, the cushion is a rear suspension of the exhaust pipe, the cushion b the front part of the main muffler hangers and the three cushions in the exhaust manifold hangers and the rear part of the main muffler have different shapes.
To protect the engine and the body base from heating by the system elements, heat shields made of heat-resistant non-woven material are installed above the exhaust manifold, additional and main mufflers and above the exhaust pipe. In addition, an additional steel heat shield is installed above the exhaust manifold.
The exhaust system does not require special maintenance. It is enough to periodically check the reliability of tightening of threaded connections and the integrity of suspension cushions. In case of damage to system elements, through corrosion or burnout, they are replaced as a whole, since the mufflers together with the pipes are non-separable units.
USEFUL TIP: Check the exhaust system periodically. If the exhaust system is noisy, check for leaks. To do this, start the engine and inspect the entire system. By running your hand over the possible leaks without touching the components, you will immediately feel the gas leak. If necessary, replace rusted and burnt components.
WARNING: Allow the exhaust system to cool before repairing it, as it becomes very hot during engine operation.
WARNING: Exhaust gases are toxic and poisoning occurs unnoticed, so be sure to open the garage door before starting the engine!
USEFUL TIP: If it is impossible to replace a defective unit with a new one, you can temporarily restore its functionality by applying a metal patch to the damaged area and securing it with clamps or wire. It is recommended to place a sheet of asbestos under the patch.
USEFUL TIP: In addition, auto parts stores sell special kits for restoring exhaust system components, with the help of which you can temporarily repair damage to the system in order to get to a car service center or garage.