1. Check the Seal Installation: Ensure that the neoprene seal is properly installed and seated in the groove. Verify that the seal is not twisted, pinched, or damaged during installation.
2. Inspect the Seal Surface: Examine the surface where the seal sits on both the engine block and the crankshaft or rear cover. Make sure there are no burrs, grooves, or irregularities that could prevent a proper seal.
3. Confirm Seal Compatibility: Double-check that the neoprene seal you used is compatible with the oil and temperature range of your Pontiac 428 engine. Different seal materials may have specific requirements and limitations.
4. Apply Sealant: Use a high-temperature RTV silicone sealant to further enhance the sealing between the seal and the surfaces. Apply a thin layer of sealant to both sides of the seal and let it cure according to the manufacturer's instructions.
5. Tighten Bolts Evenly: Ensure that the bolts or fasteners securing the engine rear cover or oil pan are tightened evenly and to the specified torque values. This will help create uniform pressure on the seal.
6. Verify Crankcase Ventilation: Check the crankcase ventilation system to ensure it's functioning correctly. Excessive pressure in the crankcase can lead to oil leaks.
7. Replace the Gasket: In some cases, replacing the gasket between the engine block and the rear cover can help stop the oil leak. Make sure to use the correct gasket for your engine model.
8. Consult a Mechanic: If the oil leak persists or you're unsure about any of these steps, it may be best to consult with a qualified mechanic who has experience working on classic Pontiac engines.
Remember, it's important to address any oil leak promptly to prevent engine damage and ensure proper lubrication.
