2003 Pontiac Montana EXT

From the factory this vehicle uses a BCI 78 · 600 CCA battery, OE oil filter 12731175. Note the factory front wiper blades and cabin air filter are now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

This engine holds 4.5 qt of 5W-30 API engine oil. Torque lug nuts to 100 ft-lbs, the oil drain plug to 18.0 ft-lbs. The firing order is 1-2-3-4-5-6. Note the cylinder-head bolts finish on a torque angle (torque-to-yield) — they stretch permanently and should be replaced, not reused, during any head service.

Under the factory schedule, replace the spark plugs every 100,000 mi; coolant at 150,000 mi. The big-interval services (at 150,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.