I got my first truck today. A buddie of mine gave me his Ford Ranger that has engine issues. It sounds pretty bad. It's a 1999 Ranger with a little over 90k on it. So you guys think it's worth tearing down or should I just replace it? Attached is a video of it running. TIA

https://youtube.com/shorts/F5gaT3M6F64?si=iOY1ostwvSP-ENYw

 

Welcome to the forum

Sorry for the delay

Cold engine, open hood
Remove fan belt from crank pulley
Start engine, battery light will stay on, no alternator
Engine bay will be very quiet with no fan
See if you can localize the noise in engine or if some of it was coming from accessories
You can only run a COLD engine for 1 or 2 min without a water pump, but that is a lot of time, and you can repeat this test as much as you like when engine is COLD again