Q: Horrible belt squeal when alternator has increased load.

asked by on January 10, 2018

There is a horrible belt squeal when my alternator is under increased load (headlights on, HVAC, etc). It starts at idle ~800 rpm and gets worse on up to ~3000 rpm where it goes away, only to come back when the engine falls back to idle. Belts are brand new, replaced less than a month ago to try and fix this same issue. It sometimes happens when there is no extra load (everyhting off) but it always happens when there is increased load.

'92 Daihatsu Rocky (Daihatsu not listed in makes)

My car has 126000 miles.
My car has a manual transmission.

Check to be sure all rotating elements are in the same plane. Check belt tension. If all rotating elements are in the same plane, the belt is new and properly tension, then the likely cause is a pulley that has faulty ball bearings or dried out grease. The alternator will have a rear bearing as well that should be checked. If you request a vehicle noise diagnostic - suspect wheel bearings, the responding certified mechanic will pinpoint the origin of the noise and implement the required repairs. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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

Oil Light came on and car stopped

Unfortunately, if the Oil Light did come on, it is possible that the engine oil was low, and the engine was oil-starved. The oil should be drained in a clean pan, and examined to see if there are metal particles...

engine idle increases after shifting into park

You should first check for any vacuum leaks that would cause the engine to idle higher than normal. Even your idle in gear sound a little high. If no vacuum leaks are found in the intake or the brake booster,...

I have a 2000 Toyota Camry and I was driveing down the street and my car started makeing tucking noise and then the car turned off

If the oil pressure warning light is on, be sure not to run the engine. The oil pressure is too low for safe engine operation although there is a small possibility that the warning light circuit is simply malfunctioning (not...

Related articles

2012 Mazda CX-5 vs. 2012 Toyota RAV4: Which One Should I Buy?
Mid-size crossover SUVs are an excellent option when you need to take several friends along with you, or bring your kids along and yet still need to keep a tight leash on your purchase cost as well as your ongoing...
The Best Used Cars to Buy for Towing Light Loads
Towing Towing is tricky business and depending on the weight you’re dealing with, it really determines what vehicle is best for you. If it’s light loads you’re looking at towing, we’ve put together a list of the top five cars...
The Best Used Cars to Buy If You're Towing a Boat
If If you’re towing a boat, the vehicle that you buy is largely going to depend on the size and weight of your boat plus trailer. Most cars, realistically, aren’t cut out for the job. We recommend a pickup truck...