I have a 04 1500 2wd Qd cab with the 5.7 hemi just in the last month there has been a hissing noise coming from some where arond the motor.Does anybody know what this hissing noise might be?

 

that could be a number of things . from a belt to a pice of plastic rubbing up on something . go under there and check it out??

from my expeariance i had some whinning like you ..turned out it was the ac fan blade shroud was bent just a hair .

 

9 times out of 10 a hissing noise is a leak, probably coolant system. Check your hoses, clamps, radiators, and around the engine bay for any coolant that isn't where it's supposed to be.

 

It looks like one of the lines coming from the trans radiator to the rackenpinion is leaking could this be the problem? Sorry for the spelling

 

It could also be a vacuum leak on the intake manifold. Check the hoses for cracks.

 

The hissing seems to quite down when the truck warms up i spay so belt dressing on and it seem to get a little quiter it stated when i started running the heater.

 

Could be an idler pulley, could be a vacuum leak. Could be the power steering pump. Hard to say without hearing it. Check the PS fluid.