Skip the auto shop - Our mechanics make house calls

Q: When I turn on my car I hear a knocking noice on it and when I accelerate it's worse.and won't go fast when I accelerate it don't

asked by on

When I turn on my car I hear a knocking noice and when I accelerate it's worse.and when I go it won't go fast..the noice sound like it's coming from under hood or by transmission
My car has a manual transmission.

If the noise is coming from the engine, then it sounds like you may have bad piston connecting rod bearing. This would account for the noise getting worse and very low power. If the noise never goes away it could also be internal to the transmission or clutch assembly, though if it was from the transmission, then it would go away when sitting stationary with the clutch depressed. Before any mystery noise can be determined, I would suggest have a qualified technician, such as one from YourMechanic, come and diagnose the noise in person. This way you can get a thorough diagnosis and know exactly what repairs are needed.

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
  • When I turn on my car I hear a knocking noice on it and when I accelerate it's worse.and won't go fast when I accelerate it don't

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: Hello I have a Honda civic 97 lx the car is cranking but won't start I think that there is no current getting through I assumed it

If the engine cranks at adequate RPM, be sure there is adequate fuel in the fuel tank and that the fuel is not old. Download any OBD-II trouble codes that have been stored and examine those codes for diagnostic clues....

Q: Vacuum diagram

The vacuum diagram is in a .jpeg or .pdf format and cannot be attached to this response. Please note that the complete Factory Service Manual (FSM) for your vehicle, including the vacuum and wiring diagrams, is available on Ebay at...

Q: Idling and stalling

Hi There, It sounds like you may have a MAP sensor that is malfunctioning as the reaction seems to correlate with the different loads put on the motor. The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a...

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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.