I have a. 2002 ford f150 supercrew 2wd. It has 202,000 miles. When i start it, there is this ratling sound. It last for quite a while. I can really hear it while at about 1200-2000 rpms. I am wondering if anyone has experienced this and wut it could be. Timing chain? Lifters? Something else? Any info is appreciated.
Thanks in advance!

 

First remove the serp belt and start the engine up. If the noise is gone then suspect the belt tensioner or one of the other FEAD components.
If the noise is still there then purchase an inexpensive stethoscope (or piece of hose, long screwdriver etc.)and using the probe move around the engine and determine where the noise is coming from. Put a manual oil pressure gauge on the engine and check the pressure as well. I would guess chances are either a timing chain tensioner is shot or the serp belt tensioner bearing is bad.