Installing the rear galley oil plug with the engine in the car

by Mike Barker
Perhaps you're an ex-Chevy guy like me, or your just a newcomer performing your first Pontiac rebuild, and you committed one of the ultimate Pontiac sins: you forgot to replace the threaded galley plug in the back of the block on the passenger side.

It’s understandable as the plug is totally hidden and the brass plug above it suggests you simply bang one in and move on, especially since this is true on the driver's side a mere 3 inches or so to the left.

Desperately you search the internet, but the answer everywhere is the same: Pull the engine.

Now your standing there, gnashing your teeth about all the time you spent getting the engine in, how much time it took to diagnose the engine's problem, and how much time and effort it will take to fix it--all for a 10 cent pipe plug. Before you dust off the cherry-picker, read on and find out that it is not 'impossible' to fix this at all! It does take some hard work, but I think you'll agree that is much better then a full blown removal & reinstall of the engine.


Before you begin, there is one check you must make. Pull the distributor, and insert your index finger, feeling towards the front of the motor. If you feel a threaded hole, this will not only verify the missing plug, but also see if you can even perform the repair. If your finger cannot reach the hole, you must find someone who can do this, or pull the motor, it is that important! Now that this is done, put a rag into the distributor hole to keep stuff out until later, do not replace the distributor yet.


Besides the standard tool set, you will need the following:

1. Magnetic pickup tool
2. Cam assembly lube (optional)
3. 1 piece of 3 foot, 1/4 inch steel bar stock. This is readily
available from Home Depot (or equivalent store) in the area where the
threaded rods are kept.
4. Power drill and bits for drilling steel.
5. Bench grinder
6. Set of 8-point sockets

Now, for a quick lesson on how a Pontiac block is laid out. The lifters in a Pontiac reside above the oil galley, and are fed via small holes leading up to the lifter bores. [For the Chevy crowd, this is quite different, as on Chevys the lifters pass right through the main oil gallery.] Say a 'thanks' to the Pontiac engineers or you would be in deep trouble because the point of all this is, the main gallery is a straight, uninterrupted hole from front to back of the block. Right to where the missing plug goes.


1. Disconnect the battery and remove it.

2. Remove the fan shroud and the fan.

3. Drain the radiator and remove that as well. Completely remove both the radiator hoses from the car and disconnect the heater core return line.

4. Unbolt the alternator bracket from the water pump, loosen the lower alternator bolts, and flip the alternator to the right, away from the engine. Alternately, you could remove it altogether if your so inclined.

5. Remove the main pulley, the large crank to balancer bolt, and pull off the harmonic balancer. If you have steel lines running right up to the fuel pump, unbolt the pump form the timing cover. I had rubber, so I left it on for the next step.

6. Unbolt the timing cover (leaving the water pump on) and shift it to the right, or remove it altogether, the choice is yours. At this point you should feel like you're replacing the timing chain and essentially, that's the correct idea, trust me! Now that you have access to the timing set, remove the cam gear and chain. Remove the passenger side galley plug. Getting the idea yet?

7. Take the plug you forgot to install to a workbench or table. On the back of the plug, drill 3 holes slightly overlapped in a line using a small bit, something in the 1/16th range should do. Be very careful not to drill through the plug, especially where the hex hole is. Now, work the drill to connect the holes, forming a slot like you would find on a flat-head screw. Clean off any metal shavings from the plug.

8. Take the 3 foot bar stock to the bench grinder, and carefully grind one end to fit the slot in the plug, try to make it as precise as possible, and fit the slot as deeply as possible. Get a ratchet, and a 1/4-inch 8-point socket. This should fit the 1/4 -inch bar stock on the unground end. You now have a 3-foot, specially made screwdriver of sorts. Its show time!

9. Get the customized plug, the bar stock, the ratchet+socket, the magnetic pickup, and optionally, the cam lube and arrange them on the car so you can easily reach it all. Climb into the engine compartment and stand so you can reach the distributor hole with one hand and the front of the motor with the other hand. [For me and my 69 GTO, this meant on the passenger side straddling the sway bar facing the drivers side with left hand at the hole, right hand at the front.] What you want is to have your most precise hand in the hole and for me that is the left. You may have to remove the hood, but I didn't at 6 feet tall. Slide the bar stock into the front of the engine, through the passenger side oil gallery. Insert your index finger into the distributor hole, and stick it right into the threaded hole. Using your finger 'to see', slip the bar back through the hole so it is just on the other side of the threads. Take a deep breath; your about to perform automotive surgery. Take the pipe plug and put it on your finger tip so that the fleshy pad is in the hex-hole, which seems to help guide it. If you brought the cam lube, you might want to try 'sticking' the plug to your finger with the grease. I did mine dry. Lower the plug carefully into the hole and gently seat it on the threads. DO NOT WORRY about dropping the plug, the cam and oil pump drive close the floor of this area. If you drop the plug just pick it up with the magnetic tool, or insert the tool first and if it falls, it will stick to the magnet. Using your other hand, push the bar forward gently, and rotate it till the head slips into the slot. Rotate the plug COUNTER-CLOCKWISE to tighten it (remember--you're on the back of the plug so the loosen-tighten directions are reversed). Once the plug is started, remove your finger and use that hand to hold the bar in place, while the other hand puts the ratchet and socket on. Tighten the plug being sure you have the ratchet set to Counter-Clockwise. Victory is yours.

Notes: Do not attempt to put the plug in upside down using a matching hex-shaped bar (they sell these too). The last thread of the plug locks it flush, but since you have it upside-down, this is the first thread and it will not start. Guess how I know. Dont worry if you can't torque the plug down. If it leaks, it will just help lube the distributor gears. Before I completely re-assembled, after putting the front plug and timing set back on I grabbed the oil pump priming shaft (note that a Chevy priming shaft works fine) and verified I was getting pressure in this area. Beware some oil will shoot out the timing set lubricating hole.


This is no easy fix. You have to basically pull the front of the motor along with the radiator and distributor. If you have AC or have to pull the hood, you have even more work to do, but consider this: you have to do most of these steps to remove the engine anyhow. Even if you somehow manage to drop the plug into the crankcase, which I think is not possible; you would have to pull the motor anyhow. It's a case of cutting your losses. This repair took me about 4-5 hours by myself, as opposed to having to get a friend to help pull the motor and then spend a whole weekend replacing it.