Skip the auto shop - Our mechanics make house calls

Q: 2004 Chevy Express makes noise while idling

asked by on

2004 Chevy Express 1500 402,000 miles. It makes a moaning sound when idling and gets louder the higher the RPM is. Transmission shifts kind of hard. What do you recommend?

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: ETM update

In order to get these updates, you would need to go to a mechanic that can update the software; a dealer should be able to reprogram the computer to the new version. This vehicle has many recalls, and service campaigns,...

Q: Car idling erratically

Hello. The erratic idling could be caused by several things: You could have a bad mass air flow sensor, the throttle position sensor could be bad, or the idle air control valve could be bad. This could also be an...

Q: New motor now electrical problems

If it's a "new" motor, and the bearings are possibly dry (they shouldn't be, but you never know), you can pre-lube the motor by using a Pre-Lube Engine Oiler Tank. After ensuring there is oil throughout the motor, verify that...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...