High-pitched whine in 6th gear in a Pontiac Vibe GT

I have a 6-speed 2005 Pontiac Vibe GT (aka Toyota Matrix) and have recently (6 months) noticed a barely audible high pitched whine when in 6th gear (only 6th gear). The noise seems to increase in pitch with speed and disappear immediately when I take my foot off the gas and return immediately when I press the gas again. My temporary solution has been to turn the radio on or ask my girlfriend how work was at which point the noise magically becomes unnoticable, but I’m concerned that this solution might not help the problem in the long run if it is indeed a problem. Can anyone tell me what the noise might be and what if anything I should do about it?

Gears will whine when they are damaged. It will get worse. Eventually, it will fail and the gear will be lost.

What is your mileage? When was the last transmission fluid change? What does the manual say about transmission fluid changes? You could try a fluid change to see if it will quiet down. If not, the transmission will need to be disassembled to fix this.

My guess is that 6th gear is an “overdrive” where the output shaft from the transmission turns faster than the engine. It seems to me that there may be some gear noise when two gears have to mesh with each other. In old cars, top gear was high which was direct drive–there were no gears involved. However, there was often some sound in the other gears. In the early 1950’s, my brother and I could distinguish certain cars by the sound the cars made as they took off from a stop. This was in the days when most cars had manual transmissions.

I think changing the fluid in the transmission might be a good precaution, as has been suggested. However, I don’t think a barely audible whine is anything to worry about. My first car, a 1947 Pontiac, had a worn cluster gear. It really sounded bad when I would start off. I would shift to second as quickly as possible. However, even this problem didn’t stop the car.

I also remember riding home from college in buses owned by a local bus company. The bus fleet were the Flxible (yes the spelling is correct) buses powered by what I believe were Buick inline 8 engines. The top gear was an overdrive and there was a high pitched whine as the bus traveled down the highway. My ears would ring for several hours after getting off the bus. I wish that the whine in the gear would have been barely audible.

Well, geeze, I hope it’s not the gear failing, and yes, it is an overdrive. The gear oil has never been changed to my knowledge (had the car since 30k miles) and it has 60k on it now. My understanding is that changing gear oil (vice transmission fluid) shouldn’t really need to be done very often. The car has about 60k miles on it right now, and the manual recommends changing the gear oil at 60k, then again at 120k or something like that, but states that it is only necessarry if the car has been driven hard or has been used for towing. Neither is the case. Maybe you’re both right though, changing the gear oil is probably a small investment to make to preserve the transmission. I don’t think I’m ready to tear the tranny down and rebuild at this point… it’s a quiet whine, and paying to have that done would make my pocketbook whine louder than the tranny!

Should have bought the extended powertrain warranty Eh? In reality that gear would have to be singing not mearly whining to get it repaired under extended warranty. You would get a lot of “normal” operation and so forth.

Any idea on the model transmission and who GM bought it from?

A whine is usually caused by a gear mesh problem. This means a flaw in the manufacturing process or the possibility of someone whaling on it a bit.

You bought the car with 30k miles and state the car has never been used for towing or driven hard. How do you know this?

Hmm, not sure about the transmission manufacturer. Wikipedia says it’s a C60 made by Toyota M.C, which sounds about right. I have heard that this car has one primary weak spot: the clutch (mine’s ok so far, knock on wood!). Also a lot of people have had to replace the automatic transmissions, but no major issues with the manuals.

Of course I don’t know what the car was used for before I bought it, could have been drug running through Baja for all I know. There is no sign of it ever having a tow hitch, so I can only hope it wasn’t used for towing anything… I bought the car from an Audi dealer. According to the old records left in the glove box it had one owner who was a woman who changed the oil regularly and paid WAY too much for the car when she bought it ($29k!).

I’m tempted to wave my hand and say to myself “You don’t need to worry about your transmission.”

Maybe I’ll just put $200 into a tranny fund each month, and get ready to replace it in a year or two (cheaper than that exended warantee!). If it doesn’t fail I’ll go on a cruise.

I’m tempted to wave my hand and say to myself “You don’t need to worry about your transmission”.

As I said in earlier posts, I’ve ridden in a lot of vehicles that had gear whine. It didn’t stop these vehicles, but if the whine was really loud, it could be annoying. Back in the 1950’s, a lot of cars developed noise in the ring and pinion gears. My dad drove a Buick 70,000 miles with this noise. Eventually it got so loud that he did have it repaired. Change the transmission fluid and put $200 in a fund each month. When you can’t stand the noise any more, then get it repaired.

I agree with Triedag.

Putting aside a couple of hundred $$ aside per month for a repair fund is a good idea, but I would couple that with changing the transmission fluid a.s.a.p.

Maintaining that it only needs a fluid change at 60k if it has been subjected to extreme service is really not valid, simply because you don’t know how the car was driven before you bought it, whether there is a trailer hitch or not.

And, consider this–What if the trans lube is a bit on the low side as a result of not having been filled completely at the factory? Or–what if the previous owner did have the trans serviced and the wrong type of fluid was put in it?

Either of those scenarios could have taken their toll by now. Changing the fluid can’t undo any excess wear that has taken place, but it might forestall transmission failure until your repair fund has been built-up a bit.

In car years, your Pontiac Vibe is middle-aged. When I was in my middle-age period, I whined a bit. Wait until your Pontiac transmission becomes a senior citizen like me–it will really growl.

Do a google search and you’ll find a lot of discussion about the 2003-5 Matrix/Vibe with early manual transmission bearing failures. Many at less then 100K miles. Might be cheaper to get the trans overhauled now before a bearing self destructs and contaminates the rest of the tranny.

I hadn’t thought of the possibility of an early bearing failure. This could,in fact, be the source of the whine. I did have the front bearing of the manual transmission on my 1965 Rambler start making noise. It was repaired under warranty. Bearing whine is more serious than gear whine in causing the transmission to self-destruct. Gears can seemingly whine forever without causing problems. In re-reading the OP, I wonder if the problem might be a bearing, since the problem disappears when the accelerator is released.