corolla 2002 loud noise when speeding

[dupche]

Hello i noticed my car has been a little louder when its in idle. But its not loud enough to bug me cos i guess its just old age. But i am worried when it gets a lot louder when i am on the freeway. Under 100km/hr its fine but as soon as i increase the speed above 100km it gets a lot noisier and a bit less when i go over 120km/hr and quiet down back to normal if i drop down below 100km/hr.
Is this a big problem? Can i leave it alone and dont have to worry about it.

Thanks,

[Brian R.]

Where is this noise coming from? Does it go away if you change the transmission gear to neutral? Does it change when the transmission changes gears? Louder around corners? Front or back of car? Under the hood?

Try to describe what it sounds like.

[dupche]

hi brian,

its an automatic, it only sounds louder once it goes over 100 n goes a bit quieter once it goes pass 120 and back to normal once it drops 100 n under.on idle the louder than usual noise if at the back. but the loud noise when accelerating is from the engine

[augusto]

brian, i have the same problem now after i bypassed my ac compressor.its more like a growling sound on the right tire everytime i speed up over 100km more noticeably whenever i speed up.this happened when i change my winter tires to my regular all season tires and rotated them.i was thinking it might be my front bearing?if it is, is it advisable to go and change them including the hub housing?thank you.

[Brian R.]

@dupche: It sounds to me like you have an exhaust leak in the flex pipe or in the flex pipe connections, just before the catalytic converter. It is not critical to fix as long as you don't get a check engine light. I would change it just the same because it affects your fuel/air mixture.

@augusto: try moving the tires around and see if the noise moves. It may be your tire. If it stays in the same place, it may be your wheel bearing, which you need to change in a shop. I don't know if you have to change the hub housing.

[dupche]

thanks for the diagnosis brian. there is no check light yet. does that mean it would effect the cars performance and/or fuel cost? money is a bit tight now so i try to hold on for as long as possible .

thanks again

[Brian R.]

Originally Posted by dupche

thanks for the diagnosis brian. there is no check light yet. does that mean it would effect the cars performance and/or fuel cost? money is a bit tight now so i try to hold on for as long as possible .

thanks again

It's hard to say whether the difference is important or not. I would get it changed (if indeed it is the problem) as soon as you can. I would have someone diagnose the problem in person. Internet is not a very good way to solve a noise problem.

[dupche]

hi brian, i checked again, the sound is coming from the muffler. but the noise that i was talking about when the car rises above 100-110 is that due to the muffler or engine?

cheers,

[Brian R.]

If it's the flex pipe, it is between the engine exhaust manifold and the cat converter.

[dupche]

i just had it checked with the mechanic before. he couldnt find any leaks or hiss sounds of leaks. he tap the muffler and couldnt find any rattling noise. i told him that it gets even louder on the freeway and will get a test drive with me tomorrow. he said that maybe it could be with the wheel. any new suggestions?

thanks