Genuine 2006 Audi A3 Cylinder Head

2006 Audi A3 Cylinder Head Parts and Q&A

• Q: What tools and steps are required for lapping-in valves on the Cylinder Head on 2006 Audi A3?

  A: This operation will need a valve spring compressor tool. In the case of SOHC petrol engines, to ensure the creation of a gas-tight seal between the valves and their seats, lap-in of the valves with fine/coarse grinding paste and a grinding tool will be required which may be a rubber sucker-type tool or an automatic rotary tool. Apply a small portion of fine grinding paste on the face of the sealing of the valve head, invert the cylinder head with the combustion chambers towards the sky, and force the valve in the proper guide, and fix the grinding tool to the valve head. Grind the valve head into the seat by a backward/forward rotary motion; occasionally, lift off and turn the valve in order to redistribute the grinding paste. Repeat until a continuous, solid grey ring of even width is obtained on both sides, and the same with the rest of the valves. In case the valves and seats are in a very bad condition, which is pitted, coarse grinding paste might be required, but remember not to exceed the allowable reworking limit of the valves and seats. When it can be repaired, begin with coarse grinding paste to a dull finish, and then wipe off with solvent and apply fine grinding paste to the proper finish. When grinding, clean off all traces of grinding paste by solvent, and allow to dry. Turn the cylinder head on its side, lubricate the valve stem with clean engine oil, and then put the valve in its guide. When fitting the valve stem, fit a protective plastic sleeve on the end of the valve stem to protect the oil seal. Take a new valve guide stem seal, and in clean engine oil dip it and then fit it on the valve guide using a long reach socket or a tool which fits the valve stem seal. Take off the protective sleeve, place the valve spring onto the valve stem making sure that it is fully seated, insert the upper spring seat, and a valve spring compressor does the compressing to the spring until the upper seat is clear of the collet grooves. Install the split collets again, take off the compressor slowly, and ensure that the collets are in position. Continue with the other parts of the valves, giving a blow to the end of each stem of the valves with a mallet to get them in position, and ensuring that the split collets are well-seated. Re-fit any auxiliary brackets and timing belt tensioner pulley, tighten with nut and washer and where necessary again refit camshaft position sensor, coolant housing and new seal, camshaft, hydraulic tappets and inlet and exhaust manifolds. In the case of DOHC petrol engine, follow the same steps but install the inlet and exhaust manifolds. In the case of diesel engines the timing belt tensioner pulley, fuel injectors, glow plugs, hydraulic tappets, camshaft and inlet and exhaust manifolds (including the turbocharger) are refitted.