Q: 2004 Chevy Express makes noise while idling

The first thing you’d want to check is the power steering. A lot of times, they groan on those. If it’s not the power steering, a lot of times it would be the transmission. If it’s coming from the transmission, you’d want to pin-point where the noise is coming from inside there.

If you don’t have the equipment, call on a professional technician, such as one from YourMechanic. Depending on the situation they may put various mics on parts of the car and put on headphones on to listen to it with a receiver to see where the noises are coming from. If it isn’t the transmission, it’s probably going to need a rebuild. But you could try adding one quart of Lucas transmission fluid. That can sometimes help for a while. However, you’ll want to have the noise diagnosed if you want to find a long-term repair and prevent any further troubles.