Super strange Transmission noise

[virgilio992]

Hello Folk! Sorry to bother you, but i'm experiencing a super-strange problem with my late 2010 Toyota Yaris 1KR-FE with 5 gears manual (yep, i'm european).
It's super hard to explain, that's why i will upload a video ASAP if requested. That's what's happening: when i reach an high number of revs (over 3500-4000 rpm) i hear a strange "cartoony" noise that disappears all by itself ( around 3-5s). Sometimes i hear it when i change gear but, most of the time, it's on the high revs. It doesn't happen all the times, but it's worrying! Personally i suspect a gearbox\transmission issue. My Toyota has 54 000 km (about 37 000 miles), it happens with ALL the gears except the 4th and 5th. I have NO problem inserting the gears, it's all fluid as usual. The problem started around december when i changed my brake fluid, coul be related? Hope you will help me sorting this out,

Andrew

[virgilio992]

https://www.youtube.com/watch?v=eo94ID3kKnI
here's the video, you can hear it (it's not quite easy unfortunately) between 0:09 and 0:11.. it sounds like this https://www.youtube.com/watch?v=fan15rky1pg
please guys help me, i'm going nuts!!!

[CTScott]

It does sound odd. Are you sure it is the transmission and not the exhaust that is making the noise?

[virgilio992]

mmmh i've never thought about it! How can i verify if it's my exhaust? It isn't a rattling sound by the way.....

[CTScott]

Originally Posted by virgilio992

mmmh i've never thought about it! How can i verify if it's my exhaust? It isn't a rattling sound by the way.....

Rev the engine in neutral to see if you still hear the noise.

[virgilio992]

it doesn't i noticed that i can hear the noise after a 20-30 mins driving it's hard to hear it before that amount of time! PS: can't go to a toyota dealership, it's more than an 100 miles away!

[CTScott]

Originally Posted by virgilio992

it doesn't i noticed that i can hear the noise after a 20-30 mins driving it's hard to hear it before that amount of time! PS: can't go to a toyota dealership, it's more than an 100 miles away!

It might not happen until it heats up. Once you start hearing the sound, then try the revving in neutral.

[virgilio992]

i'll try tomorrow morning! (GMT +1 ! ) if it does the noise revving in neutral, what could be the solution? :\

[CTScott]

Originally Posted by virgilio992

i'll try tomorrow morning! (GMT +1 ! ) if it does the noise revving in neutral, what could be the solution? :\

If it does it in neutral it could be a crack in the manifold or bad gasket between the manifold and exhaust.

[virgilio992]

Ok i checked out and it DOES the noise revving in neutral! What can i do to fix this out? At least i think we can exclude a gearbox problem!

[CTScott]

Originally Posted by virgilio992

Ok i checked out and it DOES the noise revving in neutral! What can i do to fix this out? At least i think we can exclude a gearbox problem!

That's good that it is not the gearbox. It is likely exhaust related, so now it is a matter of figuring out where it leaks when hot. You can try shining a light while someone else revs the car (once it is hot) or you can bring it to a shop where they can put it up on a lift to look from under.

[virgilio992]

Thank you so much! I will try to shine a light with the help of a buddy of mine... unfortunately in italy it costs 50$ just to lift up your car..... i hope that the it would be cheap to solve it out

[CTScott]

Originally Posted by virgilio992

Thank you so much! I will try to shine a light with the help of a buddy of mine... unfortunately in italy it costs 50$ just to lift up your car..... i hope that the it would be cheap to solve it out

If your remove the aluminum heat shield from the exhaust manifold you will be able so see better.

Out of curiosity, in what part of Italy are you located?

[virgilio992]

I'll see ASAP!
i'm actually here:

[CTScott]

Originally Posted by virgilio992

I'll see ASAP!
i'm actually here:

Ah, very good. I have never been that far south on the eastern side of Italy, except passing by there on a cruise ship.

[virgilio992]

you should, the place is beautiful except for people's bad actitude