So this 1997 Nissan Altima came in with a really bad engine noise. At first I thought it was the alternator but it turned out to be something else. You'll have to watch the video to find out what. The purpose of this video is to show a logical method of finding an engine noise like this. If it's a rotational noise like this was, I like to start by removing the drive belts one at a time. If you remove all the drive belts and you still hear the noise, it's something inside the engine. Could be the timing belt or chain. Either way, you're going to have to dig deeper if removing the belts doesn't reveal the source of the noise. Below is a link to a video I did on finding noises that may also help you. Along with an article I wrote about the same topic. So if you have an engine noise you can use that information to help you find the source.Useful links.Finding Noises Video: http://www.youtube.com/watch?v=6mpNRJ7m-c8Finding Noises Article: http://www.ericthecarguy.com/faq/diagnosing-noises-in-your-carMisfire Diagnosis on this engine: http://www.youtube.com/watch?v=V43OTGPxYc0Intake gasket replacement Part 1: http://www.youtube.com/watch?v=GKFJxnn4IIQIntake gasket replacement Part 2: http://www.youtube.com/watch?v=L_G2BE0iYnETools.1/4 Screwdriver bit: http://www.jbtoolsales.com/sk-hand-tools-81841-bit-slotted-screwdriver-1-4-x-1-4-shank/#oid=1002_1Discussion about this video: http://www.ericthecarguy.com/kunena/18-The-EricTheCarGuy-Video-Forum/50187-how-to-find-engine-noises#91831The best place for answers to your automotive questions: http://www.ericthecarguy.comEricTheCarGuy code lookup: http://www.ericthecarguy.com/obd-code-lookupFacebook: https://www.facebook.com/EricTheCarGuy?fref=tsTwitter: https://twitter.com/EricTheCarGuyGoogle+: https://plus.google.com/100195180196698058780/postsInformation on Premium Membership: https://www.ericthecarguy.com/premium-content-streaming-etcg-contentStay DirtyETCGDue to factors beyond the control of EricTheCarGuy, it cannot guarantee against unauthorized modifications of this information, or improper use of this information.  EricTheCarGuy assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. EricTheCarGuy recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video.  Due to factors beyond the control of EricTheCarGuy, no information contained in this video shall create any express or implied warranty or guarantee of any particular result.  Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not EricTheCarGuy.