The need to test the turbine of a diesel engine with your own hands may arise for a number of reasons. Carrying out diagnostics of a turbocharger at a service station often requires certain financial costs, as experts in most cases connect diagnostic equipment, remove the turbine from the engine for inspection.
To detect faults yourself without removing the turbine, you can use several methods of diagnosis. The following direct or indirect signs may indicate problems with the turbocharger, which are manifested in the operation of the power unit:
- appearance of black, bluish or bluish exhaust smoke;
- the diesel works noisily in various modes under load;
- the temperature rises, the motor tends to overheat;
- fuel and engine oil consumption increases;
- the engine loses power, traction and dynamics fall;
We also recommend reading the article about it, why a diesel engine can smoke black exhaust. In this article you will learn about the methods of diagnosis and possible faults in such a smoking power unit.
It should be noted at the outset, that such symptoms can occur not only due to turbine malfunctions, but this item is also on the list.
Visual inspection
At the initial stage of diagnosis, the level and quality of diesel engine oil should be checked. It is also necessary to exclude the possibility of foreign objects entering the turbocharger.
Next, we proceed to the analysis of the color of the exhaust gases. The drop in power and the black color of the diesel exhaust indicates the enrichment of the mixture. This may indicate an insufficient supply to the cylinders due to a fault in the intake. The thrust of the diesel engine can also be lost as a result of leaks at the outlet.
To check the engine, you need to start and evaluate the sounds during the operation of the turbocharger. The turbine should not whistle or creak, there should be no sound of air breaking through the connection. The condition and tightness of the pipe connections must be checked, on which air supply is carried out. Any leaks or damage are not allowed. The condition of the air filter must also be checked, as contamination and reduction of its capacity will lead to insufficient air supply to the cylinders.
The turbine must be additionally checked for wear. To diagnose, the turbine rotor must be rotated around its axis. The presence of a small backlash is quite acceptable. In that case, if the rotor touches the housing, the turbine needs repair.
If the diesel smokes white or bluish exhaust, then this indicates that oil has entered the engine cylinders and burned in the working chamber. Such a fault may be due to a fault in the turbocharger, and other components of the internal combustion engine. High oil consumption also indicates a problem (about a liter on 1 thousand. Walked km.)
In this case, it is necessary to return to the inspection of the air filter and turbine rotor. Contaminated filter allows a small amount of air, which leads to a strong pressure difference between the turbine housing and the cartridge with bearings. Oil begins to flow from this cartridge into the compressor housing. If no faults are detected, then it is necessary to start inspection of a drain oil pipeline for existence of bends, cracks and other defects.
Another reason for the increase in pressure may be the active ingress of gases from the combustion chamber into the crankcase, which interferes with the normal drainage of oil from the turbine. This fault may be due to a problem with the crankcase ventilation system, diesel starts Soap. On the engine with the serviceable turbine in an inlet and final collector there should be no signs of plentiful hit of oil.
We also recommend reading the article about it, why breather diesel engine. In this article you will learn about the reasons for the increase in pressure in the crankcase of a diesel engine.
Again, we analyze the state of the turbine on the axial play. If everything is fine with the compressor, then the reasons for the presence of oil in the turbine is to increase the pressure in the crankcase. Additionally, the presence of a plug in the drain oil line is possible.
In the case of noisy ??diesel work you need to check the piping, through which air is supplied under pressure, as well as the turbocharger rotor. The turbine rotor must not touch the walls during scrolling. The condition of the turbine impeller deserves special attention. Any cracks or signs of impeller damage require immediate repair of the compressor. If noticeable rotor defects are detected, the turbine must be removed for detailed diagnosis.
The backlash during axial removal of the turbine shaft should not be noticeable, as the allowable backlash is 0,05 mm and you will not feel it. The displacement of the shaft in the radial direction allows the presence of a micro-backlash (permissible value of about 1 mm.), Which is a little felt. If during the assessment of the turbine condition strong deviations from these requirements and indicators are noticed, then the compressor can be considered severely worn or defective.
Check the turbocharger on the started engine
Check the turbine for supercharging should be as follows:
- invite an assistant;
- start the engine;
- determine the pipe, which connects the intake manifold and turbocharger;
- squeeze the specified pipe with your hand;
- the assistant should gas for a few seconds;
If the compressor is running, then the pipe will have to be significantly inflated. In the absence of turbine performance, this will not happen. Additionally, the general condition of the pipes should be assessed, as well as to exclude the possibility of cracks and other defects of the intake and exhaust manifold of the diesel engine.