Whirring sound initially, now light grating or grinding...

[MrMazda92]

At first I thought it was my imagination, but I've had a problem come up recently.

When I'm driving around town(low RPMs, so the engine is quiet), I hear a quiet whirring noise from my engine/tranny, it started in 4th gear only.

After a few days, I noticed the whirring in 3rd and 5th, also around town(highway roadnoise makes it impossible to hear).

Around the same time as the whirring began in 3rd/5th, the noise in 4th started to sound more like a grating noise. At this point, it constantly makes the whirring noise, and occasionally the grating one.

I had a transmission rebuilt and swapped in to replace my original one last year, I'm currently checking the warranty status, but I'm unsure what may be the problem.

Tomorrow I'll be checking the Trans Fluid, I just wanted to see if there may be anything else I should check immediately.

My Mx3 is my daily driver, and I'm scared to cause/continue any problems with it, so I'm stuck waiting for my girlfriend's car every day.

Thanks for the help guys, hopefully I'm just over-complicating things.

Edit: By the way, It's a 5 speed... in case having 5 gears didn't make that obvious

[_-Night-Shade-_]

How's your shifter, is it sloppy?

[MrMazda92]

It feels normal, with about 3/4" of play side to side, which is the minimum I could get with my bronzoil's, without tightening it to where I had a hard time shifting. It may have about 30% more vibration than normal, but I have no real way to measure.

[_-Night-Shade-_]

Hmmmm if your bushings are good then that's probably not the issue. But how would tightening them down make it harder to shift? What if they got loose? You should post a sound clip or something so that we have a better idea of what the problem is.

[MrMazda92]

I figured it was axle related, I tightened them to the point where there was less than a millimeter of slop(No slop, honestly), and the amount of pressure it took to shift increased drastically. It went from a light, albeit slightly loose shift, to a tight, difficult shift. I adjusted it 10 or so times and the closest balance I could find was the current position. The tranny end of the linkage is perfect, it's the shifter side that caused the variation.

As for the whining, I've had a recurring problem with bouncing idle, exactly 500 RPMs up and down, for a while now. At first it was only with the heater on at 2/4, hot air coming through, and as of today it's nonstop so long as the car is running. Even when in gear and accelerating. I'm going to attempt a diagnosis tomorrow... Any ideas?

[_-Night-Shade-_]

Honestly man I couldn't tell you without hearing it.

[MrMazda92]

http://www.youtube.com/watch?v=-miVzX0KyCg" onclick="window.open(this.href);return false;

Last night, after I tried teaching my girlfriend to drive stick, it started bouncing again as we swapped seats for the drive home.

1,000-1,500 bounce, hard to hear with the ticking, but it's there.

The first portion of the clip is the engine bay, the 2nd is behind the muffler, the 3rd is driver perspective.

[_-Night-Shade-_]

I didn't hear any whirring at all but damn that is some loud a-- ticking! And I'm pretty sure the idle is bouncing because your idle screw is too open, try turning it down with ten and ground jumped after the car has warmed up.

[MrMazda92]

The whirring only occurs while driving, the car was parked in neutral when I took that video.

I ran my idle at 1,300 for easier driving during busy traffic, so I wouldn't need ANY throttle to avoid bogging.

I recently dropped it back down to 700-900ish, thinking it had to do with the whining. It's never consistent, but always in that range. Everything off, no hvac/radio/lights/anything, fully warmed up it still varies between 7-900 rpms, it has always been about 200 variable RPM, since I've owned the car.

I originally thought the ticking was sticky lifters, so I ran an engine flush through with cheap oil, heated to operating temp, and then drained. A ton of crap came out, I did another change with Castrol 5w30 Full synthetic, and a Napa Gold ZR1 filter. It ran stronger than ever, but the "ticking" got a great deal louder. I'm now inclined to believe it's the friction gear spring, as illustrated in Ryan's thread here: viewtopic.php?f=15&t=75440

The thing is, it ticks when cold... barely. When warm, it's as loud as that video shows. I get dirty looks everywhere I go, and I honestly don't have a schedule that is consistent enough to set aside time and check it out.

The whirring hasn't been a problem since I dropped the idle. However, the jumping is present about 75% of the time, where it was about 5% before... I'll repost in the v6 tech/perf section with a fitting title.

[Inodoro Pereyra]

Hmmm...you can easily determine if the ticking is due to valves or FGS. Just rev the engine over 3000/3500 RPM. If the ticking disappears, it's the FGS, if it doesn't, it's the valves.

Bouncy idle is normally a sensor or vacuum problem. Most of the times, it's the MAF/VAF, that needs to be replaced. But the VAF is expensive, so I'd recommend you to see if you can borrow one from another MX'er, to try it.

About the whirring...here's when my bad English comes to bite me in the a$$...
I don't know what whirring is...Sorry...

[MrMazda92]

Hmmm...you can easily determine if the ticking is due to valves or FGS. Just rev the engine over 3000/3500 RPM. If the ticking disappears, it's the FGS, if it doesn't, it's the valves.

Bouncy idle is normally a sensor or vacuum problem. Most of the times, it's the MAF/VAF, that needs to be replaced. But the VAF is expensive, so I'd recommend you to see if you can borrow one from another MX'er, to try it.

About the whirring...here's when my bad English comes to bite me in the a$$...
I don't know what whirring is...Sorry...

I tried that, and the engine is far too loud for me to differentiate the sounds. Also, it is coming from the right side of both VCs, nowhere else.

I'm inclined to think it's a vacuum problem, the worst part is that it comes and goes. I'll do the WD40 test the next time it bounces for more than a minute, whenever that'll be. Good tip on the VAF, there's a parts K8 here in town for sale, I'll see if the owner can part with the VAF for a pittance.

The whirring would be best described as spinning, or rotating... similar to a bad wheel bearing, but VERY quiet. That problem has 100% gone away since I tweaked the idle down, the jumping and ticking are my only problems now.

[Inodoro Pereyra]

Believe me: loud or not, if the FGS ticking goes away, you WILL notice. Either way, replacing the FGSs is really inexpensive (you can get both FGSs and both nuts for about $60, or if you reuse the nuts like Ryan did, both springs would be less than $25), although they can be a PITA.

Anyways, let us know how it goes.

[MrMazda92]

I ditched the stock airbox and put my short ram back on, the bouncy idle went away immediately, and I have more power than before. I forgot how much that helps... I'll never go back ;o

[_-Night-Shade-_]

I ditched the stock airbox and put my short ram back on, the bouncy idle went away immediately, and I have more power than before. I forgot how much that helps... I'll never go back ;o

You had cracks in the stock intake that you didn't notice? Fail.

[MrMazda92]

Not at all, honestly. I think the weird L shaped attachment(resonator? Idk) was loosely attached, I tightened it when I put the cone on, which sounds/feels better anyways. I also fixed my idle, it runs at ~650 beautifully, like brand new. Good day, now I just have to fix little things to be golden. DS window, Sunroof(motors for both), alternator seems weak, and my touchpad entry will keep me busy for a while.