Here my question

At roughly about 4600-4800 rpm I get this sort of howling noise/very slight vibration coming from the engine only at this rpm. If i raise or lower the rpm it goes away just when it hits that sweet spot between 4600 and 4800. It doesn't matter whether the car is moving or the clutch is in or out it still makes the noise.

Any idea about what it might be.

Thanks

 

bump

 

Are you running an after market intake or header? You might just be hearing the resonance of that part in that rpm range.

 

tranny whine?

 

No, their is no intake, yet. Everything is stock. the noise is a howling/sort of mixed ringing, lol hard to explain . When driving the noise is more noticable. Then if i free reved it when stoped. And happens whether the clutch is in or out.

As for the tranny the only thing i can think of would be the input shaft bearing, which would be ok because im going to have the tranny rebuilt sometime this winter. I just hope this noise isn't something in the engine internally.

Think it might have something to due with the valve adjustment or the timing belt components?

 

bump

 

try running the engine at the same speed with the drivebelts removed,it cud be a worn bearing in the alternator or p/s pump etc.also,and this might sound strange,but ive owned several civics and all of them have a kind of buzzing noise that comes in around the rpms u describe,and it turns out it was the bar for holding the hood up rattling against the body!wrap some foam or something around it and see.

 

K went out and removed the belts and checked the hood prop, no difference. Good guess tho, woulda hoped it was the p/s pump.

You know that sound you get when you blow on the opening of a glass bottle, pretty much hollow sound only a little higher pitch.

 

ok ,still rekon its a rotating part,cud be under the timing belt cover,water pump,tensioner,u say it doesnt matter whether the cluth is in or out?hope u get it sussed.