Is it an exhaust manifold gasket or worse?
 

Bought project ranger. 2000 3.0 . Had a couple issues, the guy couldn’t get it to run right,he thought it had a spark problem. He Changed plugs and wires and couldn’t figure it out. So when I went to look at it, I immediately saw a blown fuse for the evap sensor and all that so I left it alone and ended up buying it from him. Went back the next day with some tools and fuses, just got lucky and a frayed wire touching the frame on the evap sensor connector, disconnected that and put in a new fuse and it ran decent, drove it to my boys shop, while driving it. Has decent power off the line and in park or neutral, she idles decent she revs up and sounds absolutely perfect, but while driving she sounds like she has an exhaust manifold leak, feels a little shitty. Replaced the coil, because we noticed a crack in the plastic, didn’t change anything. I held my hand over the exhaust and reved it up a little. Sounds perfect and no manifold leaks or exhaust leaks… and it does have a bad mass airflow that I’m replacing tomorrow. But we didn’t think a mass airflow would cause that noise… am I missing somthing or could the heads just be bad?, or a crack in the manifold I’m missing? Going to be going over it more tomorrow night.. like I said in park or neutral she idles and revs up and sounds like a perfect running engine with no exhaust leak or manifold leak or anything

Welcome to the forum

Not a lot to go on

When engine is cold you can remove the fan belt from the crank pulley
Start engine, Battery light will stay on, no alternator
You can run the cold engine 60-90 seconds without water pump, which is plenty of time to track down a noise
Engine bay will be VERY QUIET with no fan or accessories spinning
And you can repeat this test when engine is cold again

If you have a noise only "in gear" then could be coming from transmission

The CEL(check engine light) would have been on from the blown fuse
Does it stay off now?

CEL will come on with key on, means computer has powered up, also tells you if bulb is burned out, if it doesn't come on
But codes will still be set, so check them

After I fixed the wire, fuse is fine.. check engine light popped on for maf sensor. I have to put that in tomorrow. Besides that no codes… and my boy no offense to him isn’t any help and tells me to just drive it until something really happens or the motor shits the bed.. personally I like to figure out what’s going on before shit isn’t fixable.. ill take the belt off tomorrow and see if I hear anything
and it just sounds like a manifold leak but I couldn’t find one or see anything that looked suspicious even after we were plugging the exhaust up but will try what you said