Genuine Mercedes-Benz 190E Intake Valve

Mercedes-Benz 190E Intake Valve Parts and Q&A

• Intake Valve
  102-053-15-01
  Q: What steps should be taken for thorough cleaning and inspection of the cylinder head and intake valve components during an engine overhaul on Mercedes-Benz 190E?

  A:

  The complete cleaning of the Cylinder Head and valve parts, and then, a careful examination will help you to decide on what exactly needs valve service work during the engine overhaul. Start by scraping off any old gasket material on the head of the cylinder and any carbon deposits on the combustion chambers and ports and wash out the cylinder head with a lot of paraffin or equally acceptable solvent. Any deposits of heavy carbon upon the valves ought to be scraped off, and the valve heads, and stems, may be cleaned with a power-driven wire brush. Examine the cylinder head, including the presence or absence of cracks, coolant leaks, or other damage; cracks in the cylinder head are considered good reasons to get a new cylinder head. Test the cylinder head gasket surface with a straight-edge and feeler blade, and, where distorted, may be machined provided the height is not lower than specified. Check the valve seats, either by tapping them, cracking them, or burning them; badly burnt seats will require replacement or re-cutting; slightly pitted seats may be veneered with fine valve-grinding compound. Check valve guides are used to monitor wear by fitting in the corresponding valve and measuring side-to-side movement; over movement requires the guides to be reamed or renewed. Check surface of camshaft bearings and condition and wear, in extreme cases consult a specialist on what to do about rebore, etc. In diesel engines, inspect the protrusion of the swirl chamber particularly where the face of the cylinder head is machined, make adjustments where needed with sealing spacers. On each valve, check pitting, burning, cracks, and overall wear and also measure valve stem diameter against any significant difference suggesting wear. When satisfactory, grind the valves into their correct seating positions with the proper valve-grinding compound keeping the valves gas-tight. Wipe all the compound off after grinding. Examine valve springs and look to see how much it is burnt and that their free length is within specifications also check any damaged or distorted springs. Last, check the rocker gear and score valve lifters, replacing parts when needed.