Diagnostics — knocking in the engine compartment (Focus Turnier 1)

If the engine is cold, then knocking in the engine compartment is not necessarily a cause for concern. On the contrary, when the engine is warm, knocking and noises during rotation almost always indicate serious damage. The most common damage is to the connecting rod bearings. The main bearings of the crankshaft - there are five of them in your Focus - break less often. Bearing damage always entails an extensive overhaul of the engine. With great luck and good hearing, you will recognize bearing damage at an early stage. If so, then it is enough to simply replace the plain bearing shells of the corresponding connecting rod or main bearing - although usually a specialist will advise you to carry out more extensive repairs (grinding the crankshaft, nitriding, installing new bearings) or buy an engine section.

This is how you recognize bearing damage

Accelerate the engine on the spot to medium speed and release the gas. If a light knocking sound appears as the speed decreases ("knock-knock-knock") and you notice a similar noise also during smooth acceleration, then immediately check the engine in a specialized workshop. Noises are typical for damage to the connecting rod bearing.

The ignored initial light knocking "knock-knock-knock" will turn into a hard knock after a few kilometers: the bearing damage has worsened, the liner has already worn out and most likely has led to damage to the crankshaft. You can no longer think about inexpensive repairs. It is necessary to purchase an exchange engine or an engine section.

A steady, rolling noise in the connecting rod-crank mechanism that increases synchronously with the engine speed most often indicates damage to the main bearing. Immediately turn off the engine and have the damage diagnosed in a workshop. If you wait too long, the engine block will become unusable as an exchange unit. This will unnecessarily make the repair cost soar, since your seller will calculate the unusable block as a new part.