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Difficult starting of diesel engines

  1. Low compression in the engine cylinders
  2. Wear of the fuel pump injector
  3. Thickening of diesel fuel at low temperatures
  4. clogging or Injector malfunction, black exhaust fumes
  5. Malfunction of the cranking starter or weak accumulator
  6. Injection system malfunction
  7. Malfunction of the glow control unit and failure of the glow plugs
  8. Clogging of the fuel filter


  1. With low compression, cold engine starting is difficult. The warm start is not so difficult, but the engine does not start jerkily, like with an explosion, but slowly. Reasons for such low compression are cylinder wear, worn or destroyed piston rings, coking on piston rings, leaking or burnt valves, burning of the piston crown.

    Reasons for such low compression are cylinder wear, wear or destruction of piston rings, coking of piston rings, leaking or burned valves, burning of piston crowns.

    If the piston rings are coked, it is recommended Anticarbon - Add agents to decarbonize the piston rings in each cylinder through the glow plugs or nozzle openings. It is recommended Atomex TotalFlush - to use the oil system cleaner for engines against coking before changing the oil.

    In the case of non-critical wear of the cylinders and piston rings, it is recommended to carry out a complete treatment of the engine's oil system with Revitalizant® for diesel engines or AMC Maximum mit 1 Stage Revitalizant® to do.

  2. The second and most common reason for a hard hot start of the diesel engine is the wear of the fuel pump injector. When this element of the fuel pump wears out, the piston can still pump cold fuel. But when the fuel is heated a bit, it becomes thinner and is not pumped to the extent required for a normal diesel engine start. Non-critical wear of the fuel pump injection element can be eliminated by preliminary rinsing with special cleaners and further treatment of the fuel system with XADO Gel-Revitalizant® for fuel injection devices. We recommend using the following flushing systems for diesel engine fuel systems:

    It is recommended to use the following XADO Revitalizant® to restore the fuel pump injector:

  3. In order to reduce the pour point of diesel fuel by 7-12ºС, it is recommended to add the following agents to the still liquid diesel fuel at an ambient temperature of up to +5ºС and below:

  4. If the injectors are heavily soiled, it is recommended to use the fuel system cleaners specified in point 2 on a regular basis.

    Black exhaust gases during engine operation can be caused by the critical amount of deposits in the diesel particulate filter (DPF). To clean the diesel particle filter and to prevent deposits, it is recommended to use Verylube particle filter protection (diesel).

    In the event of injector malfunctions, it is recommended to carry out a status diagnosis of the injectors and, if necessary, to replace them.

  5. If the spin starter malfunctions, it must be repaired. A weak starter battery must be charged or replaced.
  6. If the injection system malfunctions, please consult your car workshop.
  7. Glow control unit malfunction and glow plug failure should be eliminated by testing the glow plug operation, or if necessary, the glow plugs should be replaced.
  8. If the fuel filter is clogged, it must be replaced and the fuel system rinsed further as a preventative measure using the means specified in point 2 (after rinsing the fuel system, replace the fuel filter again if necessary).
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