issues with my 99 explorer, please help!

[Firecracker680]

Just bought a 99 explorer sport with 4x4 and having a few issues. First it runs rough and stalls while the engine is cold, once it warms up I have to restart it and then runs fine. The tranny shifts rough and to first take off you have to put it in 1st then once it starts moving you have to put it in drive. Also makes a loud hum at 35-45 MPH and gets louder the faster you go. If anyone has any ideas as to what's causing these problems I would greatly appreciate it.

 

[ttbit]

Is it a 4.0 ohc engine? Do a search as intake gaskets are known to cause this problem. It happened in my 2001 ST.

 

[Firecracker680]

It's the v6 4.0 sohc. That's what I was thinking for the vacuum leak, I've heard its a common issue.