Few days ago I heard a slight knocking I could only hear it when I was actually driving and i reved it up. Took a look and could not find anything or hear where it was coming from. Now this morning on my way home from work i was losing power and the knocking was very loud and has a loud chirp to it also.

I took the valve cover off and didn't see anything wrong so I took a tube and listened around the engine. THe sound is coming from inside the engine on the passenger side behind and just under the alternator.

What do you guys this the problem is? Need a new engine? TB on this?

Thanks

Also, this happened a day or two after i added iso-heat to the fuel plus full tank of 87 octane gas. Donno if that might of had an affect. and I removed the oil plug and let some oil out but did not retreive any metal shavings with a magnetic retreiver thing.

Could it be just a loose pulley?? I'm being optimistic.

it could be also a wrist pin or a broken ring. If your loosing power it may be a compression ring. Or a sticky valve.

Knocking like, someone slaming metal on a table, many times in a row? Could be as bad as a bearing,

To check the pulleys remove the belt and start the car. Now your alternator wont be charging the battery at this time, because it runs on the same belt. Anyways if the sound is there you know it not the pulleys, its most likely the engine.




- 2004 Cavalier - 124k, owned since new

It's not like metal slamming on a table but more of a very loud chirping sound.

Not a loose pulley. and it is inside the engine.