Ever since I put the LE2 heads on, I've had a strange noise coming from the passenger's side. I wouldn't describe the noise as metallic - it's more of a compressed air noise. I tried to get a video of the car idling, but the noise wasn't identifiable in the video.

With a timing light hooked up to the #4 cylinder plug wire, the noise and the timing light appeared to be in sequence. I swapped the lifters from side to side, and the noise stayed on the passenger side. I also have readjusted the rockers a few times, and the noise remains the same. The noise is very faint when the motor is cold, and gets louder as it warms up.

Any thoughts?

 

loose spark plug? exhaust leak?

 

I tightened the plugs, and replaced the header gasket on the passenger's side. Noise is still there.

 

this may sound stupid seeing as its not happening anywhere else except the passenger side, but maybe the piston on one cylinder have hit, or be lightly tapping a valve?

 

Did ya check your P/V clearance?
The heads being milled or a change to a thinner gasket with the same or more lift they could hit.If ya went to larger valves that makes it worse yet even on just one cyl as the tolerances are not that close on a stock short block.
Ya can bet if ONE is hitting the REST are pretty CLOSE to hitting.

 

Mine did this, and I found the noise comes from the injector. Kinda odd. I had them cleaned, noise is still there. On a scanner though, everything looks fine, even at WOT. Just a noisy injector for some reason?

 

Well, the noise isn't the injectors - I just tested them by unplugging them one cylinder at a time, and the noise is still there. The biggest clue to the noise may be the fact that I can't even hear it when the car is cold. After idling for 2-3 minutes, I can start to hear it, then after 5 or so minutes of running, it gets louder.

 

Anyone have any thoughts?

 

possibly a bad valve seat. i dont think a head gasket would make that sound.