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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29522
Experience:  GM Grand Master Technician 2007. 14 years experience.
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My car ran low on oil and now there is a knocking sound what

Customer Question

if my car ran low on oil and now there is a knocking sound what may be the cause
Submitted: 7 years ago.
Category: Chevy
Expert:  JOHN aka Eauto replied 7 years ago.
HiCustomer Thank you for asking your question on JustAnswer. The most likley cause is bearing failure like rod, or main bearings or cam bearings. The motor will need to be opened up to find cause of failure

Thank you again for trusting us with your problem.
Customer: replied 7 years ago.
Relist: Answer quality.
not enough info
Expert:  GM Tech (Cam) replied 7 years ago.

Greetings and Welcome to Just answer.

Does the knock change with engine speed? what I mean is this, does the knock get worse with engine speed or does it stay the same?


Customer: replied 7 years ago.
It gets worse. theres an immediate knock as it starts then calms with idle... and know increases with rpm
Expert:  GM Tech (Cam) replied 7 years ago.

OK, Does it sound deep and near the bottom or light and near the top?

What does it say about the oil pressure?

Customer: replied 7 years ago.
its hard to tell. to me its loud and sound like the lower block area
Expert:  GM Tech (Cam) replied 7 years ago.
OK, that is the bad one. For it to get worse on higher RPM suggest more of a rod knock. So you do have bearing damage. These bearings require oil pressure to fill the small gap and provide not only lubrication, but also heat transfer. You do need to remove the oil pan for sure and inspect the bearings.
Customer: replied 7 years ago.
yea that was my fear... will i be able to get away with removing the pan and replacing the bearings maybe rods. without having to mess with the crank itself or balancer.
Expert:  GM Tech (Cam) replied 7 years ago.

That will depend on the damage to the crank and rods. YOu will have to inspect and see for sure.


Customer: replied 7 years ago.
Good point. thanks a lot. you were way more help than the first guy. sorry to pick ur brain but as far as bearings do u suggest aftermarket or stock. and i performed an oil change when i replaced the solenoid. so i havent really driven on the new oil. now the fact that there might be shavings suggest i should change it again aswell right
Expert:  GM Tech (Cam) replied 7 years ago.

If you pull the pan, replace the oil. It really does not matter with a stock application. Factory will be just find.


Customer: replied 7 years ago.
thanks for the help
Expert:  GM Tech (Cam) replied 7 years ago.

My pleasure.


Expert:  JOHN aka Eauto replied 7 years ago.

these motors do not do well when they starve for oil. The bearings damage quickly, It would be more cost effective to either get a good used motor or a reman motor

for a used motor try for a reman try jasper engines

Expert:  GM Tech (Cam) replied 7 years ago.

If this is all you are in need of, pleace click the accept so your deposit will be released to me. You can reply at any time if you need.