Tips for spark plug replacement on 4.5 and 4.9 Cadillac V-8 engines.

Cylinder 1: no special tools or techniques needed.

Cylinder 3: Remove the plastic or metal AIR tubes for easier access to spark plug.

Cylinder 5: no special tools or techniques needed.

Cylinder 7: no special tools or techniques needed.

Cylinder 2: elevate car on ramps or jack stands; remove spark plug from under the car.

Cylinder 4: elevate car on ramps or jack stands; remove spark plug from under the car.

Cylinder 6: Remove rubber AIR tube to for easier access to spark plug; remove spark plug from above – you’ll have to lean over or lay over the engine to reach it.

Cylinder 8: Remove spark plug from above – you’ll have to lean over or lay over the engine to reach it. You’ll need two 3” ratchet extensions.


Front bank of cylinders are number 1, 3, 5, 7, from left to right while standing in front of the car looking at the engine.

Rear bank of cylinders are number 2, 4, 6, 8, from left to right while standing in front of the car looking at the engine.