Genuine 1985 Pontiac Fiero Cylinder Head

1985 Pontiac Fiero Cylinder Head Parts Questions & Experts Answers

• Q:

  How to clean and reassemble the cylinder head with new valve seals on 1985 Pontiac Fiero?

  Posted by Danetta C.

  A:

  Even if the head isn't sent to an automotive repair shop for valve servicing, it must be clean before reassembly. For a V6, new seals should be installed on each valve guide using a seal installation tool or a hammer and deep socket, ensuring each seal is gently tapped into place without twisting or cocking them to maintain proper sealing on the valve stems. Starting at one end of the head, lubricate and install the first valve with engine assembly lube, moly-base grease, or clean engine oil on the valve stem. Next, drop the spring seat or shim(s) over the valve guide and set the valve spring, shield, and retainer in place. Compress the spring with a valve spring compressor and carefully install the O-ring oil seal in the lower groove of the valve stem, ensuring it lies flat without twisting. Position the keepers in the upper groove, then slowly release the compressor to ensure the keepers seat properly, applying a small dab of grease to hold them in place if necessary. This procedure should be repeated for the remaining valves, ensuring all components are returned to their original locations without mixing them up. Finally, double-check the installed valve spring height; if it was correct before disassembly, it should still be within specified limits. If not, an additional valve spring seat shim can be installed to achieve the correct height, but caution must be taken not to shim the springs to a point where the installed height is less than specified.

  Answered by GM Parts Specialist Jeremy / Oct 04, 2025