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

Forgot to add that 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.

so it only happens on heavy accel? is it a light pinging or a heavy knocking?

if you think its coming from cyl1, can you unplug the #1 injector and make the sound go away? is it constant and consistant, or is it once/twice per revolution? or is it erratic?


wtf is iso-heat?

post your year/model/mileage.

have you checked the oil level?

2002 cavalier 2.2 ecotec 67,000

it started out making the sound only under heavy accel but now it is even doing it under idle. When i first noticed the noise it just sounds like an exhaust leak but it gradually got louder and started gradually losing power. I will have to unplug that injector tomorrow. It is constant and consistant...not like something is bouncing around.

here is the isoheet its like gas line antifreeze/water remover

It could be a rod knock, that means the bearing at the end of the rod on the crankshaft is shot.

It could also be piston slap but that should go away after the engine warms up.