Lately, I've noticed a really weird sound coming from the engine compartment when at idle. I opened up the hood today while it was running, and the sound is definitely coming from under the plastic piece between the cam cover and the supercharger. It's a very hard sound to describe; almost a grind , but kinda like a sputter. It actually sounds like a spray gun trying to spray out small pieces of dried up paint, only more rough. It seems to go away if I hit the throttle, but I may just not be able to hear it over the engine revving and the sound of the exhaust. I hear it whether the engine is cold or hot, & other than this sound, it idles fine, and it pulls hard without any dead spots or anything. As far as mods go, I only have a K&N air filter in it. Does anybody have any ideas??? Thanks,

Matt Gandenberger

 

Two things i've seen so far are the plastic injector adapters blow their o-rings or the injector it'self lost an o-ring. I bet it's the retainer/adapter cup.

 

If worried you can always take it in and have it checked out. It may just be lifter noise (the Ecotec motors have lifter noise it is normal mainly due to being hydraulic i would imagine).

 

Thats a pretty amazing feat since we don't have lifters Could also be a timing chain tensioner?

 

Well the car does have lifters (though not lifters of the old crank type) but what I was meaning was the hydraulic rollers, my bad. And I forgot about that noisy ass chain that is in there as well. I do believe the timing chain is much better than the typical timing belt that alot of 4 cylinders use...

 

No, we don't have lifters. How can you have a lifter when the cam sits on top of the valves?? Now since we have (some of us) dual valves, they use whats called a follower on top. Not trying to be an a$$, just teaching the correct info

 

maybe they aren't really refered to as "lifters" anymore, but this is direct from GM's ecotec engine specs:

Valve Lifters: Hydraulic roller finger followers

 

My neon had lifters but technically they are followers. They sit offset of the cams and read off the top of the cam then actuate the valves.

We have the same setups

Honda have the cam directly actuating the cam tho

http://www.gm.com/company/gmtunersou...rque_specs.pdf

See page 81

From page 83
Mechanical Lifter Various Crower/Jesel/Bates Engineering
Billet rockers Various Bates Engineering/Jesel
Production Rocker Arm 12565203 GM
Cast Rocker Arm with Solid Lifter — Bates Engineering

 

blown o-ring for sure this happened to mine b/c it was not properly inserted some mechanic must have bumped it somehow but you might have a vacuum leake from this which would make a hissing sound and in a boost situation ie. when you get on throttle it would go away buy size 10-16 orings one should fit.

 

blown o-ring for sure this happened to mine b/c it was not properly inserted some mechanic must have bumped it somehow but you might have a vacuum leake from this which would make a hissing sound and in a boost situation ie. when you get on throttle it would go away buy size 10-16 orings one should fit.

 

sure its not coming from your S/C? mine makes a noise like what you are describing. also, on my last motor i had a loud clicking noise for the first 5 minutes of the motor running after a cold start. came from the timing chain side. i never found out what it was since my motor was swapped out due to a coolant leak. i could hear that over the engine revs though. the supercharger noise goes away when i rev it.