Timing Chain: Service and Repair

1990 Chevrolet Lumina APV V6-191 3.1LSECTION Service and Repair

Fig. 7 Valve Timing Marks:






1. Remove front cover as described under FRONT COVER.
2. Place No. 1 piston at top dead center with marks on camshaft and crankshaft sprockets aligned, Fig. 7.
3. Remove camshaft sprocket bolts, then remove sprocket and timing chain. If sprocket does not come off easily, tap lower edge of sprocket with a plastic mallet.
4. Install timing chain on camshaft sprocket. Hold sprocket vertically with chain hanging down and align marks on camshaft and crankshaft sprockets.
5. Align dowel pin hole in sprocket with dowel pin on camshaft, then install sprocket on camshaft.
6. Using camshaft sprocket attaching bolts, draw sprocket on camshaft. Tighten bolts to specifications.
7. Lubricate timing chain with engine oil, then install front cover as outlined previously.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.