Skip the auto shop - Our mechanics make house calls

Q: Engine is knocking loudly and has a weak acceleration.

asked by on

When we left this morning, the car ran normally. We stopped at the gas station and as we were pulling in we started to hear a slight knocking. As we pulled further in, the knocking became louder. We checked the oil level and noticed it was low. We hadn't kept a close check on it recently as we should have. We filled the oil to the correct level. The car engine continued to knock and when I tried driving it home I noticed a huge problem when trying to accelerate. It moved very slowly at first and finally kicked in and gained a little more speed. The car has no problem starting but continues to run with the loud knocking. The car is a 2005 Ford Five Hundred. I've owned the car for about a year and a half and was told it had a new engine put in just before I got it. The knocking sounds like it's coming from the top of the engine. My car has 157000 miles.
My car has an automatic transmission. *Update: We drained the oil and there were no metal shavings in the oil

A: You may have damaged the engine bearings by...

You may have damaged the engine bearings by running it low on oil. I would suggest not driving it until you have an engine mechanic listen to and diagnose where the noise is coming from. If the noise is up top then you may have jumped timing or the cam is damaged. If the noise is in the lower engine, then the bearings could have failed. If you need help, a technician from YourMechanic can inspect the noise and verify the fault so that correct repairs can be made.

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!

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: Timing chain too loose

Hello. The rattling sound that you are hearing could be coming from several different areas of the engine. Your drive belt pulley could be bad, a compressor clutch could be loose, or the alternator pulley or timing chain could be...

Q: How do you add oil to the engine?

Ideally, you’ll never have to add oil to your engine, but it is definitely possible, particularly if you go for long periods between oil changes (not recommended). If you check the oil and find that the level is below the...

Q: Car stuck in park

First of all, be sure that you are fully depressing the brake pedal. With modern day vehicles, the shifter will not move out of park without the brake pedal depressed as a standard safety feature. If this is not fixing...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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...