Has a "rod knocking speed" type of noise under the hood listened to from the drivers seat.Its only at idle and goes completely away off idle.
I took delivery of this new car for my mother back in 05 and heard this noise on the test drive.I ask the salesman at the time and he said that noise was made by all the new Ions.He gave me an explanation at the time but I don''t remember what it was.The Ion has had all its 3000 mile oil changes and the noise is the same today as it was when delivered.The noise seems to come and go.Sometimes it does it and sometimes it doesn''t.I''ve put about 6000 miles on the car.The engine runs perfectly.I really don''t fear this is a rod or piston knock but I would be interested if anyone else has the same noise and if they know what it is.Thanks

 

Of the five ION''s that have lived at this house none made or make a loud rod knocking sound at idle or any other time that could be thought to be coming from the engine. Might it sound as though it''s coming from the trunk?, as in the purge canister soliniod.

 

Its not loud,its fairly low in tone and volume.It sounds more hollow.
Pretty sure its coming from the front.
Edited by: 12v testlight

 

After working with this car a little with a sensor code issue I have been wondering if the noise I hear that seems to come from the engine area could be the computer advancing the timing to the edge of spark knock when the engine is at idle ?