Skip the auto shop - Our mechanics make house calls

Q: My aftermarket crankshaft pulley is wobbling a little when it idles. Does it just need to be tightened, or replaced?

asked by on

Really concerned here. Heard a weird noise coming from my engine. Looked under the hood with my friend and saw my harmonic balancer/crankshaft pulley wobbling a little at an idle. It doesn't shake or wobble after I rev up the engine though. I have the aluminum aftermarket 3sx pulley on there so I don't know why it's doing that. It was also professionally installed. Is there a way to just tighten it or should I replace the pulley all together? I have a used one off of a parts car that I know for a fact works, but obviously if I don't have to remove it I don't want to. I'd just rather keep the one that's on there in case all I have to do is tighten it. I have the automatic transmission by the way. Thanks.

My car has 200000 miles.
My car has an automatic transmission.

The harmonic balancer should not wobble at all. The heavy bolt that holds the balancer to the crankshaft snout is quite tight. Presumably the balancer bolt was torqued to the Factory Service Manual value, and so you cannot safely tighten it any further and even if you did it wouldn’t make any difference because the balancer is fixed in position against a shoulder on the snout. You could check to make sure the bolt was actually tightened though to the torque specification. If the bolt was tightened, the crankshaft snout is not bent, and yet the balancer wobbles, the balancer is defective. If you desire that the balancer be examined to determine if it is defective, and replace it if required, please request harmonic balancer diagnostic/replacement and the responding certified mechanic will get this resolved for you. 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?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • My aftermarket crankshaft pulley is wobbling a little when it idles. Does it just need to be tightened, or replaced?

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

Q: Car starts but turns off

In many situations like yours, the first thing a mechanic will do is compete a diagnostic scan to determine if any error codes are stored in the computer. All of the options you listed are potential sources of the problem....

Q: How long can it take an ECU computer to go bad?

Hello, and thank you for writing in. The vehicle likely did not suddenly develop all of these problems. Oil leaks in particular happen due to excessive engine wear. The spark plugs and their coils tend to be regular maintenance with...

Q: The car through a serpentine belt

If the coolant leak still exists, the recommended service would be a leak diagnostic(https://www.yourmechanic.com/services/coolant-is-leaking-inspection). It is possible that a seized water pump bearing can throw the belt but all other causes, including bearing roughness in additional pulleys, have to be...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...