Help Diagnosing Noises
Thread Starter
Cruising
Joined: May 2025
Posts: 13
Likes: 4
From: Minnesota
Help Diagnosing Noises
After driving my 85 C4 for a while, I started noticing a couple sounds. They are two distinct noises, but one is semi-constant and the other isn't.
One is a noise I can only describe as metal discs spinning against each other, it happens only while accelerating and gets louder the harder I press the gas. It doesn't happen when cruising, or revving in park/neutral.
The other is a horrible grinding/crunching sound that happens mostly when accelerating after turning. The guy at Top 5 Auto Repairs has a perfect recreation of what I hear. at 28s
From what I've looked up, I'm thinking it's something with the Differential and/or Transmission, but I don't want to be too hasty since I'm no expert.
One is a noise I can only describe as metal discs spinning against each other, it happens only while accelerating and gets louder the harder I press the gas. It doesn't happen when cruising, or revving in park/neutral.
The other is a horrible grinding/crunching sound that happens mostly when accelerating after turning. The guy at Top 5 Auto Repairs has a perfect recreation of what I hear. at 28s
From what I've looked up, I'm thinking it's something with the Differential and/or Transmission, but I don't want to be too hasty since I'm no expert.
Racer
Joined: Mar 2025
Posts: 489
Likes: 235
Your video doesn't work but for sound #2 that occurs when accelerating while turning, take the car out to an empty parking lot or another area where there is plenty of space and move your steering wheel back and forth while accelerating and/or moving forward. If the sound gets louder when the car is leaning either right or left then many times it could be the wheel bearing on that side. That's the old school mechanic's way of identifying which bearing is bad.
I'll let someone else speculate on sound #1.
I'll let someone else speculate on sound #1.
Pro
Joined: Jul 2023
Posts: 533
Likes: 278
From: Marysville WA
Last edited by typical boomer; Nov 6, 2025 at 07:59 PM.
