Lack of engine oil/ low oil pressure (seizuring of bearing)
Confirm the oil content /oil pressure, blockage of oil pipe
Turbocharger has high percentage of recurrence of same problem. The best solution is find the basic cause and prevent.
Please confirm removed broken turbocharger by appearance; follow the direction below to prevent.
The most of the problem caused by engine and it is rare for turbocharger problem.
Unusual worn occurs by problem of lube from engine.
Lack of engine oil/ low oil pressure (seizuring of bearing)
Confirm the oil content /oil pressure, blockage of oil pipe
Foreign objects in oil (bearing scratches)
Adhere of bypath connection valve for oil filter
Sludge inside of oil cooler
Contamination of cut chip for repairing engine in the oil
Diluted engine oil (Excessive worn for bearing)
Mixing gas oil in engine oil
The vehicles (2-4tons) and buses which occurs DPF forcible regeneration frequently.
Overrun for rotor (Excessive worn of bearing)
Overrun for roter by losing control of VGS
Air leak by contamination
Fixation of controll valve for air cylinder
Turbocharger overrun because of engine overrun
Please exchange both engine oil and oil filter when the turbocharger is replaced.
How to check the clearance of the shaft; put the dial gauge to oil drain port. Hold the compressor/turbine wheel with both hands and move parrallel to measure. For easy way to confirm, rotate the rotor forward without any wheel rub to housing.
Do not rotate the rotor opposite way. It may cause damage to thrust bearing.
For small-middle truck or city bus after EURO4 (regulation code: ACG,ADG,AKG) , has rare opportunity to run higways. For vehicles has many opportunity for DPD/DPF forcible regeneration, please read below carefully.
When regenerate DPD/DPF forcible, non-conbution oil mix the engine oil and may cause low viscosity of oil. This is caused excessive worn of the bearing of turbocharger.
If the oil level is between high and low, it is possible to use. If the oil level is over the hole, it means low oil viscosity. Please exchange the oil immediately.
Please use the oil from recommended by manufacture (e.g. DH-2) or sulfer-free fuel (diesel fuel). Using other oil/fuel makes more sulfer in exhaust gas and increase PM(soot) oxidation catalyst.
If there is damage on turbine wheel brade, it may cause high-cycle fatigue; sympathic bibration by rotor overrun.
If there is the oil leak for trucks and buses turbocharger before EUROⅡ-Ⅲ and does not have PCV, please refer the cause of the problem below.
Turbocharger works correctly with high temperature.
Oil from breather is sucked into compressor side. Then oil come out from housing. This is misjudged as oil leak from turbocharger.
The oil inlet for turbocharger is too small, and there is no possibility to suck so many oil into it.
If the DTC(diagnosis trouble code) has appeared for VG turbo with electric actuator, it is important to deal with it carefully. Theare many cases there is no problem with turbocharger even if the code has appeared and replaced.
Check List
Check the ECU, boost sensor, and speed sensor.
Any corrosion or snap wire for the connector of actuator or harness between the vehicle
Check the voltage for battery
Check the EGR, DPD (DPF)
Check the VG controll system (it may not work well by over-voltage)
Confirmation for re-programming. (For Hino vehicles including buses)
DTC (Diagnosis Trouble Code)
・P0045 ・U1123 ・U0073
What is DPF (Diesel Paticulate Filter)?
DPF is filter system for remove the soot from exhaust gas in diesel engine. If the DPF collect soot and fulfill the filter. The function will be lower with clogging filter. DPF DPF regeneration(burn the soot to remove) is remove the clogging the soot from filter.
DPF regeneration and turbocharger, built up the carbon on VG nozzle parts
Any oil marks on compressor inlet or a lot of carbon on turbine outlet, the carbon built up on VG nozzle and linkage and cause the mulfunction of nozzle (lack of air supply)
The oil leak from turbo does not make any soot.
The oil suction from oil separater, the oil pooled inside of the intercooler.
Starting or running the engine, pooled oil sucked into cylinder and fire.
There is the possibility of break the turbocharger. The engine does not stop even if it is turned off, engine overrun or the detornation has occurred while driving.
Oil supply hole for turbocharger is too small to suck so much oil in engine.
The damage mainly causes on turbine wheel, the natural frequency of turbine wheel brade and pressure change of exhaust gas causes sympathic vibration and make a crack on it.
Especially for VGS turbocharger is difficult to avoid the pressure change for exhaust gas.
Turbo is overloaded by mulfunction of VG actuator, turbo is overloaded and it may cause the danger the breakage above.
There is frequent mulfunction for air leak especially for air cylinder.
Main cause → Lack of maintain the air dryer
For some model, deformation /crack of turbine housing and VG nozzle by high temperature occurs in high percentage.
For many return cores happen same problem.
Crack or deformation caused mulfunction of VG nozzle. There are some synptoms of over boost and lack of acceleration.
Please confirm unusual increasing the temperature of exhaust gas and fix it. It may cause same problem in short term.
The main cause of increasing exhaust gas temperature
If there are deformation or crack on turbocharger or exhaust manifold, engine may have problem; unusual combustion or increase of exhaust gas temperature by causes below.
Unusual combustion by injector problem
Bad spray/Mark on dribbling fuel
Please check the injector and exchange if it is necessary.
Exhaust gas temperature is increased by mulfuction of tappet roller.
(Problem of exhaust gas progress → heat accumulation
Please check the camshaft and tappet and exchange these if necessary.
Noise from inside of the turbocharger means damaged and no functions at all.
There is possibility to replace the turbocharger without any problem only by misjudge for noise.
Air/gas leak from boost hose, bibrating sound or whistling sound of the plumbing part
The sympathetic sound/ resonant sound from engine parts around the turbocharger
Please confirm the list above and take care if it is necessary.
If there is lack of boost pressure/ lack of acceleration without any problem on turbocharger appearance, please confirm the reason below.
Drive mode turn to safty mode, lack of acceleration by overboost (vehicle controlled by computer), stucking/destruction for air cleaner, intake hose or pipes, lack of boost for intercooler, lack of pressure from pipes, power source, problem of voltage (problem with ignition), snapping wire/ lack of wire(for motor type/VG turbo/VG with REA type)
