Engine operation and power
Engine power loss: where to look
Power loss is not one fault. Distinguish sudden/gradual onset, constant or load-only symptoms and cold/hot operation. Directions include insufficient fuel, air/boost, restricted exhaust, injectors, derate, EGR/DPF/SCR, mechanics and excessive hydraulic/transmission load.
Weak engine or excessive machine load?
If it revs easily unloaded but drops sharply with hydraulics or travel, also check pumps/transmission. Weak operation without working load points more toward fuel, air, exhaust and mechanics.
Fuel system
Demand rises under load, exposing faults barely noticeable at idle. Check filters, tank pickup, lift pump, low-side pressure, air ingress, Common Rail, high-pressure pump, injectors and fuel quality. Compare desired/actual pressure when power drops.
Air and turbo
The engine may receive fuel but insufficient air. Check filter, turbo, boost hoses, intercooler, clamps/connections, downstream leaks, boost sensor and EGR. Black smoke makes this direction particularly relevant.
Exhaust and aftertreatment
A heavily loaded DPF, damaged DOC/SCR, faulty flap or other obstruction produces backpressure. Check DPF differential pressure, exhaust temperatures, soot load, regeneration history, DOC/DPF/SCR condition and physical exhaust flow.
Derate: controller-imposed limiting
The ECM may reduce power for AdBlue/SCR, DPF, overheating, low oil pressure, sensor/fuel faults or other machine controllers' errors. Check whether limiting is active as well as reading codes.
Injectors and mechanics
After fuel, air and exhaust checks, consider poor injector atomization, abnormal cylinder corrections, compression, valves, timing, piston-group damage and mechanical turbo damage.
What to observe
Sudden onset, black smoke, derate, unloaded RPM, hot-only symptoms, DPF/AdBlue/fuel/boost faults, unusual turbo noise, unusual oil quantity in hoses and air-filter condition.
Related problems
Further service support
Have a fault code?
Problem still there?
If these checks have not identified the cause or the fault returns, contact TSV Servis. The more initial information you provide, the sooner we can identify the next diagnostic direction.
What to send us
Machine/engine model, S/N, hours, conditions of power loss, smoke, RPM, fuel pressure, boost, DPF/SCR values and active derate.
Include the make and model, S/N or a nameplate photo, engine model if known, operating hours, exact code or display photo and when the fault occurs.
Also tell us what you have already checked or replaced and the results. Include a photo or short video of the symptom where useful.
+420 722 307 850 · tsvcz@seznam.cz