I have a 97 ram 1500 4x4 with a 5.2 and an automatic. there is a noise coming from under the dash that is sort of a hissing noise/ boiling noise (sounds like when a radiator boils into the overflow tank) . im new to dodges and not sure what it is. it goes away when it warms up but comes back and when the engine is revved, no matter what temperature. it sounds like maybe something to do with vacuum but im not sure. any ideas?

 

are you sure it isn't a gurgling noise (like a bong hit), that would be air in the cooling system.

if it were vacuum then you could have a loss of power, lack of cruise control or the vents will switch to defrost when you hit an incline (the engine is under load).

 

your right it sounds more like a gurgling noise. so maybe air in the lines going to the heater core?

 

yep. it could be a bad radiator cap, leaking heater core, bad head gasket or just some mystery leak that is allowing air to enter from the timing cover gasket/freeze plugs/bad hose clamps/water pump/radiator.

have you seen any antifreeze on the ground or leaking anywhere on the engine/hoses?
do your windows fog up when you put the heat on defrost?
do you have a musty or sweet smell in the cab with the air on?
does your oil look like coffee with creamer in it on the dipstick?

 

i couldnt have asked that better

hows your heat anyways?

 

yea actually i know there is a radiator leak in it. the lower part of the radiator on the drivers side is separating the plastic and the aluminum are coming apart. i guess that could be the cause of it? the heat works great and i smell no coolant in the cabin.

 

heater core, check an make sure u dont have any anti freeze in your passenger side floorboard.

also like as suggested earlier could be a faulty radiator cap letting too much air in and could be the heater core is air locked or just burping out the excess air.

 

that leak is letting in air, which rises up to the highest point, which is the heater core. you'll probably need to fix it before it gets worse. you can get a new radiator on ebay for pretty reasonable. about $100 incl shipping.

 

radiator is now on the top of my list of things to do. thanks for the help everyone. we have a summit racing store in reno so maybe ill go see if they have a performance one later today

 

exacally...radiator would be first thing to start with