How to diagnose that errant noise

Tapping or ticking from the top end of the engine
→ Loose valves or other valvetrain issues

Tapping or ticking from the bottom end of engine
→ Main or rod bearing issues

Rushing air sound that increases with engine speed
→ A loose component in the intake tract

Screeching that changes with engine speed
→ Worn or loose drive belts

Pinging under acceleration
→ Ignition timing off and/or not enough high-octane fuel

Engin roaring sound (in a bad way)
→ Exhaust leak

Screaming from the front of engine
→ Worn coolant pump

Ticking from the rear of car
→ Electric fuel pump issues

Bad bearing/rattling sound that goes away when the transmission is in neutral and the clutch pedal is depressed
→ Worn input shaft bearing

Whirring that changes with car speed as well as side-to-side suspension loading
→ Bad wheel bearing

Whirring that changes with car speed
→ Tire issue

Squeaking or groaning over bumps
→ Dry or worn anti-roll bar bushings or suspension bushings

Clanking from underneath over bumps
→ Loose suspension components or worn suspensions bushings

Clanking, hollow sound from underneath over bumps
→ Loose exhaust system

Scraping or ticking sound that changes with car speed
→ Worn brake pads

Screaming from the passenger seat
→ Driving too fast or erratically

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Comments

PetervonA2 New Reader
6/22/22 11:52 a.m.

My freshly restored 1958 Giulietta Spider Veloce developed a wheezing, kazoo like sound coming from the engine. My first guess was a cylinder's header pipe was loose at the head, causing the thin cooper gasket to sound like a reed in a wind instrument. Nada. An expert's ear guessed it could be a dry cam bearing, yikes but nope, the caps were oily. The source I found finally was all eight impossible to access nuts that secure the DCO3 Webers. They were just finger tight. It takes a special set of crippled 12mm wrenches to fix that.

Cheers, Peter Pleitner

www.enjoyclassiccars.com

lasttr Reader
1/18/24 6:37 p.m.

I was amused that you used a Sunbeam Tiger as an illustration. Last August, I volunteered at the Anchorage start of the Alaska to Mexico Rally. A Tiger with a freshly rebuilt V8 was shipped up from England via the West Coast, only to develop valvetrain clatter at the start. After several attempts to resolve the problem, they flew their mechanic in from England with a new head.