Rule N₂: you can replace a faulty turbocharger with a new one without much difficulty.
Not so long ago there were times when a car with a turbocharger was automatically included in the rank of the most sporty, the most charged and, of course, the most expensive. A huge distance has been covered in the last 15 years and today it is almost impossible to find a modern diesel engine that does not have such a unit next to it.
Despite the fact that turbocharger parts operate at temperatures up to 800°C and speeds of 50,000–85,000 rpm, they are quite reliable. However, they also wear out and age, and the first turbocharger units (they became truly widespread 5–7 years ago) are already failing, and sometimes this is accompanied by serious consequences.
However, it is not always worth blaming the turbocharger for the fact that the engine suddenly began to lose power. The reason for this can be a banal clamp that has weakened and flown off the pipeline, or a broken seal.
Most often, however, the reason for the decrease in power of the power unit is a faulty turbocharger. You should not try to repair it, but replacing it is quite possible on most common cars.
In general, diesel engines are easier to repair than petrol engines due to their simple design. The most convenient are all-wheel drive vehicles, which have plenty of repair space around the engine.
The most complex are the "charged" sports models, especially those equipped with twin turbochargers. The standard work on their replacement at the dealer in this case is calculated for 12 hours. For models of such complexity, it is recommended not to even think about repairs at home, and many professionals refuse to take on it if they do not have a full set of necessary tools and devices.
However, don't give up and give up early. On most models, the turbocharger can be replaced independently. The main problem will be engine bays overcrowded with units with limited access to the engine. Manual dexterity and an S-shaped key will help here better than any special tools.
Like any repair job, replacing a turbocharger requires concentration and method. Start by clearing the assembly of pipes, wires, and other ancillary components. You'll need a lot of space because you'll need to remove four (sometimes three) exhaust manifold nuts, the downpipe, three oil feed and drain lines, and all the air supply lines. Water-cooled turbochargers are even more complicated because of the extra parts.
One of the inevitable companions of a turbocharger is high operating temperatures. As a result, the nuts that attach to the exhaust manifold are "welded" almost tightly and it is necessary to apply a significant amount of a preparation such as WD40 before starting to work with them. After replacing the main unit, it is imperative to replace the nuts with new ones made of stainless steel. If they are made of ordinary steel, then next time, it will probably be almost impossible to unscrew them.
The studs may turn a few turns when unscrewing the nuts, or even turn out completely. Check carefully for distortions and damage to the threads. If this happens, restore the threads and screw the studs back in place until they stop.
Not all turbocharger designs include a sealing gasket at the junction with the exhaust manifold. So don't be surprised if you didn't find one when dismantling this unit on your car. If there was a gasket, be sure to install a new one during subsequent assembly.
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After removing the turbocharger, check all the freed oil lines. To do this, ask someone to turn on the starter (removing the high-voltage wires from the engine to eliminate the possibility of starting it), and make sure that the oil flows freely. After installing a new turbocharger, do this procedure again so that oil flows to its bearings before the "real" work begins. Turbocharger bearings without oil - even for a second is the worst thing it can experience in its life!