94 Ex wierd engine noise

[LOGJOCKY]

Hey guys, I am back driving the 94 Explorer again. I noticed when it is colder outside i get a loud hiss/whine type noise coming from the engine when I am over 5o-60km/hr. When I slow down it goes away, speed up it comes back. Ive looked around but I cannot get it to make the noise at idle or while revving. It seems to be coming from the drivers side.

I guess it could almost be a whistle of sorts. I am not sure what this is but it doesn't do it at all when its warm out. Any ideas?

 

[cogs]

the vacuum ports are on the drivers side at the back of the engine on top (follow the hoses). one of the back hoses could have come off. also, the open port (one is unused) should be capped. check any hoses for leaks.

 

[LOGJOCKY]

Alright I will check there and see what I can find