Both of these sounds started today - after the car was in the garage for about 3 days.

First one.
When I drive on the highway there is this sound between 50 -70mph.
It sounds like it is coming from suspension or wheels area.
It is like a hollow humming sound. I did the test to make sure it is not an engine-
I accelerated to say 80-90mph and put a car in neutral - car decelerated and I could clearly hear that it comes on at about 70mph and goes away at about 50 mph.
Looks like an engine has nothing to do with it.
What can it be?

But now;
Second one –this one really worries me.
This morning was the first time I heard the sound.
After driving for about 15 minutes I floored it and when the car went on boost I heard
this very loud screech. Couple of minutes later I tried again – same thing – sounds scary
It is very loud. Car is not loosing any power.
Looks like it starts only after 12psi.
Anybody heard such a sound before??

Can these 2 sounds be connected in any way?

Please help
Thank you

 

well,

For the first sound no one can really tell. Jack the car up and make sure all the suspensions nuts are not loose.... Plus where do you live? Was it freezing outside this morning??? Your suspension could be frozen.

For the other sound, you might have a boost leak some place. Make sure that you are reaching 19 psi around 3500 RPM. Take a look at all your hoses as well.

 

First sound- yes the car was parked for 3 days where it was prolly less than 32 degrees--I hope that is the case.
Some say it might be transfer case - what are the things you notice when your TC goes bad?
BTW my car has never ever beed launched.
I see no reason to think my TC would go bad.

Second sound- I just drove the car again- boost goes to 21psi- as before, but right at the peak the car whines/whistles very loud.
I do not hold it there -not to break anything


Anybody??

 

The first sound could just be your tires, after sitting for a couple of days in cold weather they probably are flat spotted. After you drive on them for awhile and get them warm it will go away if that's what it is.

The second noise could be a belt.

 

First sound is your tire, it's wearing out. Maybe you've rotated your tires recently.

second noise is your clutch going dead or something to do with your transmission. It's chattering to the max. lol

By the way, your transmission take longer to warm up then your water tempeture or your engine. If it still makes that sound after about 30 minutes of driving, then