A faulty alternator can cause a rattle noise. If it is more of a knocking noise then it could be a rod or you can check your oil pressure gauge. Low oil pressure could also cause the knocking sound.
Jun 30, 2010 at 11:22 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.