Q: Engine is running horrible with stalling and noises under load.

asked by on

recently it suddenly started running really badly. I'll list my observations.

-Loud, low pitched roar as the engine speed increases -rough idle, revs jumping all over the place, sometimes stalling, especially if air con is on. -metallic (tappet) noise when under load, higher engine vibration, worse than usual acceleration. -Often misfires, especially in the first minutes of operation.

This group of symptons used to appear periodically in the past, but would eventually disappear a few minutes after appearing, as suddenly as they appeared. I'm more worried because it has been 3 days with these conditions, and it has not improved. I'd really like to get to the bottom of this because it doesnt seem like the usual wear and tear that an old engine like mine displays, due to the sudden onset of the bad running, and that the issue usually resolved itself in a matter of minutes. Engine is a 4A-F (carbed) with 324,000km on it.

My car has 200000 miles.
My car has a manual transmission.

Hi and thanks for contacting Your Mechanic. As for the engine misfiring and having an issue with the rough idle, there could be a vacuum leak on the engine. Check all of the vacuum hoses and the intake to see if its sealed. Also, check the brake booster to see if its leaking vacuum. For the loud noise, there could be an exhaust leak or the engine could have a worn bearing in the engine. There could be a rod bearing that has too much clearance and is causing the tapping noise under a load. Also the engine could be vibrating due to an ignition problem. Check the distributor, plug wires, and spark plugs for corrosion deposits and heat burns. Check your carburetor for any adjustments that could be out. If you have traveled to a higher or lower evaluation, then the carburetor will need to be adjusted for the altitude. This will help with the stalling of the vehicle. If you need further assistance with your vehicle, then seek out a professional, such as one from Your Mechanic, to help you with your engine misfiring having a tapping noise under heavy acceleration.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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
  1. Home
  2. Questions
  3. Engine is running horrible with stalling and noises under load.

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: Hard to shift, shaky clutch, started smoking

Hi there, thanks for writing in. I'd be happy to help. The leak is most likely from the clutch slave cylinder. Look in the clutch master cylinder reservoir and see if it is low or empty. If it is, then...

Q: Dies during idle or when put in gear.

Hello, and thank you for writing in. Everything you have done so far has been helped narrow down possible issues. You should check your vacuum supply at the intake, the intake air temperature sensor, your oxygen sensors, and the possibly...

Q: My car will not start Intermittently. I purchased a new battery 2 weeks ago and yesterday the car wouldn't start. Got a jump and

The issue you are having is probably due to an intermittent fault in the starter motor itself or a deficiency in the starter electrical circuit, for example a large voltage drop due to a poor ground or a high resistance...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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 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.