Knock Noise 2000 Chevy Blazer LS 4×4

2000 Chevy Blazer

All of the sudden started getting a knock noise and it wants to hesitate when you take off. I noticed oil towards back of engine but still have good oil pressure. Its not getting hot and no chips in oil.


The oil leak is probably nothing more than just that, a leak. Anyway you look at a noise it doesn’t look good.

Knock Noise

Lets figure out if the knock noise is internal or external from the engine. The easiest way to achieve this would be to remove the serpentine belt and start the engine. Only allow the engine to run long enough to determine if the knock no longer remains. If the noise is gone, you know the knock is external. You can check the external noise by spinning the pulleys before installing the serpentine belt.

Internal engine knock noise

2000-chevy-blazer-crankshaft-bearings

  • Knocking noise is present at engine idle. Generally disappears as engine rpms increase. This is most commonly a cause of faulty engine main bearings.
  • Knocking noise increases and sometimes gets louder as engine rpms increase. Generally the noise goes away or is faint at engine idle. This is most commonly a cause of faulty engine rod bearings.
  • On rare occasions the balance shaft bearings have been known to make a knock noise.

2000-chevy-blazer-blance-shaft

In either case you are going to end up rebuilding or replacing the engine to cure the issue.