OK I have a '99 OB with the 2.5L and 4EAT and have a strange noise that I thought I would ask the board members for an opinion on.

 

Like the title says its only when I accelerate at wide throttle and only in one specific gear (I'm not sure if it's second or third?). It sounds like a bearing noise or a whistling noise.

 

Is it likely a transmission noise or could it also be a front diff bearing? Trying to guage whether the likely fix will be a 4EAT swap?

 

Thanks for reading.

Front or rear diff would make noise in all gears.

 

I'm an expert on front pinion noise at this point

 

check out the pinion noise vids I have on youtube at CNY1RC.

Edited January 23, 201313 yr by CNY_Dave

Thanks Dave,

 

I'm just kinda wondering why its only in the one gear. I can also hear it when the transmission downshifts during an acceleration too like on the freeway.

I would say its time for a new 4eat. The gears are probably fragged. Drain your great oil and trans fluid to see if you get a present:)

It could be something silly, also. It might only move just the right way for something to make contact in 2nd, or vibrate just the right way only in 2nd.

 

The fact it only makes noise WFO is a hopeful sign.

My 2000 Legacy does the same thing when I open her up. I asked my friend about it and he said it might have something to do with the valve timing change when accelerating quickly. His volvo did it too, and that's what caused it for him.

Blu used to do this, i think maybe you may want to look someplace else.

 

With Him the Tabs for the air box were broken. At wide open throttle this would cause an air leak, hence a whistle.

 

So check to make sure your airbox (air filter) is seated if you have touched it lately.

Nipper,

 

Thanks for the advice, I did have it opened a while ago so I will check that first. Its also due for an ATF change as well so I'll do that too and see how it goes. I guess when it is in that gear and WOT it can make a noise and when it shifts, the RPM drops so that may be the reason it only does it at that time.

 

Thanks for all of the help!

I reseated the airbox cover and noise is much reduced. Thanks Nipper. I think I need to get a Subaru OEM filter (it is a solid metal frame) to reduce the likely hood of the floppy one moving around in the air box. It's due for replacement so I think I'll just put an OEM one in this time.