The exhaust manifold bolts are not power. Nevertheless, they require sufficient strength and reliability. Violation of the tightness of the junction of the exhaust pipe and the manifold is accompanied not only by undesirable acoustic effects, but can also result in other unpleasant consequences. Until the fire under the bonnet.

1. INSIGNIA A (G09)
2. INSIGNIA A Saloon (G09)
3. INSIGNIA A Sports Tourer (G09)
4. CORSA D (S07)
5. See more in applications

The need of exhaust manifold bolts usage

FA1 brand Bolt, exhaust manifold operate in difficult conditions, with assembly temperatures up to 400°C, which contributes to the rapid corrosion of the material of bolts and nuts. Especially if the latter are also made of steel. Oxidation products, which have a larger volume compared to the reacted metal, create an interference fit in threaded joints in combination with the effect of soldering. Therefore, the main test for bolts is not their operation itself, but the process of unscrewing soured nuts. Do not forget that the material of the exhaust manifold bolt undergoes changes during prolonged operation at high temperatures in combination with vibrations, which can only be said that they do not improve the properties of the bolt. In the "body" of the exhaust manifold bolt, microcracks appear, growing into just cracks, and then her days are numbered.