Groundrush

I've spent about the last hour+ searching the various threads on transmission noise, and while I've found a few sporadic posts from others with similar situations, I haven't been able to find any specific information about what this sound may be. I'll describe:

1. To begin, I do not abuse my car. I have never dropped the clutch. I do not drive it particularly hard, though I do get the revs up to 7k+ at least 3-4 times per week. It is an '05 with 20k miles on the odo.

2. The whine I am hearing can only be heard in 6th gear. It increases in pitch as the RPMs increase, and is more pronounced when accelerating or cruising. Taking my foot off the gas either significantly reduces the whine or it disappears alltogether. I do note that when I take my foot off the gas and then reapply it, the whine temporarily gets louder, and then decreases ever-so-slightly in volume and stays constant until I release the pedal or accelerate again. This is different from the other threads I've seen that report a whine when the gas pedal is released.

3. When the car is in 5th gear, there is no whine. Upon shifting to 6th, at the same speed, the whine begins, so I know it's definitely an issue with the top gear. The whine is louder than the stock exhaust.

4. Whine stops when the clutch is disengaged (pedal pushed down). There is no noticeable slipping of the clutch while in 6th gear. I've been trying, but I'm unable to pinpoint if the noise is coming from the front or the rear of the car.

This is absolutely NOT tire or wind noise. It is not a fuel issue (93+ octane always). I've read lots of non-specific information regarding syncros and rings/pinions, but the symptoms in all those cases appeared to be the opposite from mine. I'll be making an appointment with the dealership in the morning to have it looked at (along with a couple of other issues) and I'd like to have opinions from some folks with experience with this in case they try to tell me "it's normal!". If there are any known threads on this that I might have missed in my search, a redirect would be appreciated.

Thanks in advance for your comments!

Groundrush

An update, just in case anyone in the future searches on this topic. Spoke to the dealer today. They've had the car two days and anticipate having it at least two more. The tranny is out of the car and they are apparently replacing the entire 6th gear mechanism.

Service writer said the tech was able to reproduce the sound, but that they had not seen this on another 8 before. They contacted MNAO, who also stated that they had not heard of this problem before, and instructed the dealership to disassemble the tranny and inspect it. At least they didn't tell me it's normal. Should hopefully have my car back Monday at the earliest.

While I was chatting with the service writer, we got to talking about engine recalls. He indicated that the '04 engines were "disappointing", but that they have seen very few '05 and up models for engine replacements. He stated that the people that have engine failures are those that come in stating "I baby it!" and that state they rarely run it beyond 3.5k. He said to "let it run".

Shocking news obviously...but was still kind of interesting having a service writer telling me to run the hell out of my car.

Brettus

iTrader: (2)

I was going to say it was normal because I've always had this whine but it would seem it is not from your second post . Does not worry me .

Groundrush

I didn't specifically ask the CAUSE of the '04 failures, but I'll ask the next time I speak with him. I suspect he will tell me it's due to rotor seal failures due to carbon build-up, knock/detonation, etc.

Brettus, as far as this being normal, I can only say that it didn't do when I purchased the car. I have 20k on it now and recently replaced the stock Bridgestones, and due to the ridiculous amount of noise they produced, I would not have heard the whine anyway for the last several thousand miles. Only when putting on new, quieter tires was I able to discern the noise. Not sure how loud yours is, but mine is on par with the stock exhaust with the windows up. I guess if they replace the 6th gear hardware and the noise persists, I'll know. I'll post back here observations when I get the car back.

Razz1

^ good news on engine wear

Plus no moving parts to replace like piston engines.

Groundrush

Yes, I was aware that oil metering was a problem, but I know it's also commonly written here that not keeping the RPMs up is bad for these engines, allowing carbon to build up which can then interfere with the seals. His assertion that people who pamper their cars have the most engine trouble seemed to confirm this for me. It'll be interesting to see what the service writer says when I ask him specifically. I'll bring up the oil metering issue too...just to see if he has any thoughts.

Interesting that you rebuilt your own...I wouldn't have the cojones to try that myself.

Groundrush

Post-repair update: Just picked up my car from the dealership today. Overall, high marks to Indian Mound Mazda in Heath, Ohio...they took good care of me.

Basically they rebuilt my transmission per what the service writer said. 6th gear was replaced entirely. The documentation they provided indicates that they replaced the clutch sleeve, synch ring, needle bearing, synchronizer key, synch spring, the "steel ball" (?), clutch hub, retaining ring, and the 6th counter gear. Drives quiet as can be now in 6th. Service writer said that basically 6th gear was in the process of failing, so I'm glad to hear I wasn't crazy. All covered under warranty.

Sadly, they "couldn't reproduce" the shaken-BBs-in-an-Altoids-can noise coming from the engine while accelerating under load. They gave me the expected "use higher octane gas" despite the fact I repeatedly told them I use no less than 93 octane. Still, they replaced the plugs, and the car is pulling quite nicely now. The noise is still there, but notably improved. Guess I'll need to chase down the coils issue soon.

I love this car.

TrochoidMagic

^^yes, agreed. hehehe

bigireland

had the same problem but i had it in 5th and 6th.. took it to the dealer and they said that when went to check it the tranny fluid was like water.. ended up getting a new tranny as well.. i have about 1.3k miles on the new tranny but now i'm hearing it in almost all of my gears.. planning on replacing tranny/diff fluids to see if that will help at all..