Coming into work this morning I gave the car a quick sprint to about 100mph, only to notice that near the top of 4th the car made a "pop" noise. As I let off the accelerator, and noticed that the car was making a "fluttering" noise everytime I pressed on the gas. Think of the sound that'd you get if you held a piece of paper in the wind - that fluttering noise is what I'm getting.

I was afraid to get on boost till I got to work, then popped the engine bay. The car seems to not make that sound at idle, though you can hear it just a bit if you play with the throttle.

Anybody have a clue as to what happened to my car? My first guess was an IC hose, but seeing as how I can still drive and accelerate... that PLUS the fluttering sound... ?

 

BOV maybe?

 

check ic pipes... does it stall any?

 

I don't think the BOV would cause that kind of fluttering noise. This occurs in OFF BOOST conditions. I haven't tried boosting yet, it's just not a smart idea until I get this resolved.

Plus, this is a pretty loud fluttering noise. You can hear it in the cabin VERY clearly, but when the hood is open it's hard to pick it out among all the other noises.

 

No stalling.. drives just like normal.

 

fluttering noise? do you feel a lot of delay in boost?

 

umm fluttering, i would check all your boost connections, and IC pipes, i remember when i was installing my mbc i couldnt get it right, so i put everything back together, i noticed i was getting a flutter cause it wasnt on tight or what not, but check it all!

 

heard that when my Forge vacum line broke off

 

Haven't tried building boost... is it possible it could be a IC hose that is "loose" just enough so that off boost drivability isn't affected, but you cannot build boost?

For the record, I haven't tried boosting yet... thought it might not be such a hot idea.

 

That was you breaking the sound barrier flying real low. Happen to me once or twice now. Sorry this just came to me.

 

Just stabbing for something here, but... I just went to start the engine after lunch (now that everything is cold). It sounds a lot more like a rattle, almost like it's coming from the manifold. Is it possible that a stud could have broke/snapped, causing the "popping" sound? And hence, resulting in the rattling manifold. (and remember this sound occurs only when I give it gas, not while coasting)

 

Check for boost leaks, then if nothings wrong, then use some starter fluid to spray around the intake manifold while it's idling if it revs up by itself then you have a leak in your manifold.

 

Yes, most certainly.

 

i think ur bov popped off my car did the same thing

 

My buddies seems to be doing the same thing. Its a flutter that sounds like its coming from the filter. His started doing this after he had a K&N installed. I drove the car last nite and its only when you accel then gradually release the acclerator. Also his car did the same thing in 4th gear. He was accel, and then the car hesitated as if he let off the gas, then the power came back on. Any ideas?? Hes got a evo 9.