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

asked by on November 17, 2016

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?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

Battery not staying charged

Hello. The battery is basically a storage device that requires constant charging from the alternator. I would have your alternator tested. If the alternator is not the problem, I would check for a parasitic draw. This happens when something in...

My hot temperature light is blinking and the temperature is below the C mark. Is it safe to drive home?

Hi there. The coolant temperature sending unit is malfunctioning and sending the vehicle the wrong information or the gauge on the dash has failed. The sending unit could have burned inside causing the computer to think that the engine is...

How do I adjust the volume in the infotainment system?

Adjusting the volume in the infotainment system is very easy. Simply rotate the VOL knob until you reach your volume preference. The volume will increase when the knob is rotated clockwise, and decrease when the knob is rotated counterclockwise.

Related articles

A Buyer’s Guide to the 2012 Chevrolet Tahoe
The The Chevy Tahoe has always been one of the most popular SUVs on the market, and this trend continued in 2012. As always, the vehicle proved to be reliable and powerful, with plenty of space and features that people...
The Best Used Cars to Buy If You're a Carpenter
If If you're a carpenter, and working for someone else, the best used car is whatever you like that gets you to work on time and holds your tools – in short, practically any used car will do. If you...
A Buyer’s Guide to the 2012 Chevrolet Malibu Hybrid
The The 2012 Chevrolet Malibu ECO hybrid is an interesting car in the world of mid-size family sedans. Unlike other popular hybrids, it doesn’t have a full-sized electric motor that takes over when the car starts. Instead, it uses eAssist...