Q: Knocking sound when idling or stopped 1993 Chevrolet Lumina APV

asked by on

There is a rhythmic knocking sound coming from the left side of the engine (facing the engine from the front) near the serpentine belt. On the road you can't really hear it, it gets really loud when idling at a light. Then in park and running it's still there just not as loud.

My car has 230000 miles.
My car has an automatic transmission.

Hello - the rhythmic knocking you hear could be something driven by the serpentine belt (i.e. AC compressor) or the belt itself. It is also possible that this an internal noise - like the timing chain, which is immediately behind the serpentine belt on the engine. Removing the serpentine belt, then starting the engine for 20-30 seconds won’t harm the engine, but would narrow the problem to inside the engine or something belt-driven. I would recommend getting this checked out soon, as additional damage may be occurring while you drive further. A mobile, professional mechanic, such as one from YourMechanic, will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. Knocking sound when idling or stopped 1993 Chevrolet Lumina APV

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: not getting fuel to engine

Hi there: If you're not getting fuel to the injector on your 2012 Chevrolet Malibu, it could be caused by a fuel pump that is broken, an electrical relay issue or perhaps a fuse that's blown that powers the fuel...

Q: Accelerator cable came off

It sounds like the throttle cable has broke and needs to be replaced. I would have a certified technician come out and see if they can get it back on or, if it is in fact broken, have the throttle...

Q: Engine knocking

This engine has had known issues with the timing chain and tensioners. This may be the issue for your engine, but it would need to be heard by a mechanic to get a complete diagnosis. I recommend you seek a...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...