I recently noticed a humming or “hmmm” sound that seems to appear when I’m driving at speeds between 70 and 75 mph. The sound goes away as soon as I drop below 70 mph. It’s a new development; I didn’t have this sound before and just noticed it today.
I had a few repairs done recently:
Changed the outer shaft seal (which was leaking) a few weeks ago.
Changed the PTU (Power Transfer Unit) fluid.
Drained and refilled the coolant twice.
Could any of these repairs be causing this humming sound? Or might it be something else, like wind hitting something in the front? I didn’t notice any issues like this before the repairs, so I’m wondering if they might be related.
Any insights or suggestions would be greatly appreciated.
Hey,
If the outer shaft seal was recently replaced, it’s possible that the drive shaft or axle was moved or disturbed. Check to make sure that the axle and related parts are securely fastened and properly aligned. A loose or incorrectly installed axle might cause vibrations or noises at certain speeds.
Hey,
After changing the PTU fluid, make sure the PTU is properly filled and sealed. If there’s an issue with the PTU installation or the fluid level is off, it could create a noise. Check for any leaks and confirm that the fluid level is correct.
The coolant drain and refill are less likely to cause a humming noise but check if any parts removed during the process were reinstalled correctly. Make sure all hoses and connections are secure.
Wheel bearing, a common cause of humming or droning noises at specific speeds is worn wheel bearings. If the wheel bearings were disturbed during recent repairs or if they are simply old, they might be worth checking.
Check your tires for uneven wear or damage. Sometimes, noise at certain speeds can be caused by poor wheel alignment or unbalanced tires. If needed, get your tires balanced and aligned.
Hello,
Inspect all areas involved in the recent repairs carefully, checking for any loose or poorly installed parts. Then, take your car for a test drive to see if the noise stays the same, changes with speed, or shifts with acceleration. This can help you figure out if the problem is linked to speed, acceleration, or a specific part.
If you’re unable to identify the source of the noise or if the issue persists, consider taking your vehicle back to the repair shop or a professional mechanic. Explain the noise and its correlation with speed, as this information can help them diagnose the problem more effectively.