OEM GMC C3500 Spark Plug

GMC C3500 Spark Plug Parts Questions & Experts Answers

• Glow Plug
  12563554
  Q: How to replace spark plugs and spark plug wires for different engine types on GMC C3500?

  A: For removing spark plugs, disconnect the Spark Plug Wires; choose the Spark Plug wire harness replacement (5.0L-5.7L) for spark plugs and Spark Plug wire harness replacement (7.4L) for those with a 7.4l engine. Loose the spark plugs a few turns because they work best when removed from the wells. Brush off dirt from around the spark plugs and afterward, take the spark plugs out one by one, putting them into a tray matching their cylinder numbers. While installing, fit every Spark Plug washer in the right place and check the gap of the Spark Plug, changing it to match the correct specification which is 1.524 mm (0.060 in). For tightening the bolts, use 15 n.m (11 lb ft) for iron head installations of 4.3l, 5.0l and 5.7l, 20 n.m (15 lb ft) for iron head installations of 7.4l and 30 n.m (22 lb ft) for iron heads newer than those offered in 4.3l, 5.0l, 5.7l and 7.4l. After finishing the rebuild, put the Spark Plug Wires back and use the Spark Plug wire harness replacement (5.0L, 5.7L) for 5.0/5.7l models and the Spark Plug wire harness replacement (7.4L) for 7.4l engines.