Repair Pontiac Mid-size 1974-1983 Repair Guide

Engine Core Plugs (Freeze Plugs)



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Fig. Fig. 1 Using a punch and hammer, the freeze plug can be loosened in the block

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Fig. Fig. 2 Once the freeze plug has been loosened, it can be removed from the block

  1. Disconnect the negative battery cable.
  3. Drain the cooling system.

When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. If equipped with drain plugs on the engine remove them. They would be located at the bottom of the block near the oil pan.
  3. Remove any components that restrict access to the freeze plugs, like the starter or motor mounts.
  5. Wearing proper eye protection, tap the bottom edge of the freeze plug with a punch and hammer. This should tilt the freeze plug, not cut it. Then use pliers to pull the freeze or pry the freeze plug from its bore. Another method is to drill the freeze plug and use a slide hammer, but more often there's not enough room to do that.
  7. After the plug is removed clean the area completely. Coat the freeze plug and/or bore with gasket sealant.

To install:

  1. Install the freeze plug into the hole, it must go in evenly or it will keep popping back out as you tap on it. Using a plug installer or socket that fits the edge of the plug can help keep it straight as you tap it in place.
  3. Fill the engine with coolant, connect the battery cable. Start engine and check for leaks.