Can someone tell me how to check for a vacuum leak on a 2002 Dodge Ram 2500 B cargo van? It has a random up and down idle, sometimes stalls when parked but running, and a random "check gauges" light and a pegged temp gauge at the same time but temp gauge comes down almost immediately and light goes off. Is there a fix? Or does it just need a flare in the gas tank.

 

There are several things that could be wrong other than a vacuum leak. The pegged temperature gauge could be due to air in the cooling system which could've gotten in there through a blown head gasket, or it could simply be a sticky thermostat. The up/down idle and stalling can be from, a blown head gasket, a weak fuel pump, or a bad IAC valve. A vacuum leak tends to raise the idle, not lower it.

 

Thanks for the info. Will definitely have those issues checked out.