strange sound

[ussmc]

Need Help,

After my 2005 Corolla reaches its normal engine temperature, it makes a strange sound whenever it stops. It sounds like it’s under pressure or like a bomb falling. The sound goes away while driving or when the gear is on [N]. Does anyone know this problem?

[J e r e M y]

:\ im tryin really hard to imagine the sound

[trdsaads]

Maybe its your wife?!

It kinda explains the noise going away when you drive off again.

[ussmc]

:/ The sound is really hard to explain. A bomb falling really is the best way I can explain. Fukk me, I may have to take it to Toyota :/

trdsaads :) - experience?

[123R-Prozak]

a bomb falling... so like a vacuum leak? like shhhhhhhhh ?? but u can't hear it while going cause your motor noise goes over the 'bomb falling' sound? never heard a bomb falling so wont know what it sounds like

[ussmc]

It does sound like a leak, but it’s more of a robotic shhhhhhhhh.

The motor noise does not go over the sound. It goes away when I drive off or when the gear is on [N]. I only hear that sound when my foot is holding on the brake.

[123R-Prozak]

ahh... so your at the lights.. in neutral..what if you put your foot on then of then on the off and play with the brakes, does the sound go then come back??? can you feel your brake pedal pulse?? like... when you lock up with ABS..

btw auto or manual?

[ussmc]

It’s auto and it doesn’t have ABS - Not sure what you mean by pulse, but there’s nothing wrong when braking. I’ve already played with brakes, and the sound does go when my foot is off and it comes back when my foot is on (but not straight away – few seconds)

[DJKOR]

It’s auto and it doesn’t have ABS - Not sure what you mean by pulse, but there’s nothing wrong when braking. I’ve already played with brakes, and the sound does go when my foot is off and it comes back when my foot is on (but not straight away – few seconds)

To me that sounds like a leak in the vacuum booster for your brakes. One thing you can do is turn your car off with your foot off the brake. Then apply your brakes (something like half way even more) and hold for about 5 to 10 seconds, then release fully. Now apply your brakes fully. Does it feel rather difficult to apply? If your vacuum booster is fine, it should remain relatively easy to apply on the second press in that case.

Just to be sure as well, when your car is running you should get someone to apply your brakes while you have a listen in the engine bay to try and locate where it is coming from just to narrow it down.

[123R-Prozak]

It does sound like a leak, but it’s more of a robotic shhhhhhhhh.

well as you have previously mentioned it goes away when you release your brake pedal pointing into the direction of the booster, as said by DJKOR.. perhaps the diaphram in your brake booster has a leak or the hose supplying your booster has a leak.. have you noticed since the sound has accured the brake pedal isn't as easy to press by any chance + when u play with the brake pedal your rpm goes up and down?? if its a vacuum leak, your idle will go funny..

try what DJKOR said.

Edited March 22, 2009 by 123R-Prozak

[ussmc]

something like half way even more) and hold for about 5 to 10 seconds, then release fully. Now apply your brakes fully

The brake is difficult to apply only if I fully hold on the brake for 10 seconds. It can also be difficult to apply if I keep stepping on the brake on & off, on & off, and so on, then at some point it will be difficult to apply.

when u play with the brake pedal your rpm goes up and down?? if its a vacuum leak, your idle will go funny..

The rpm does not go up and down when i play with the brake pedal, but the idle does sound funny only at the first star up of the day.

Do you guys think the vacuum/ brake booster or its hose has a leak? Does it sound like it’s a job for Toyota mechanics? How much $$$ do you guys think it’s going to cost me?

[DJKOR]

something like half way even more) and hold for about 5 to 10 seconds, then release fully. Now apply your brakes fully

The brake is difficult to apply only if I fully hold on the brake for 10 seconds. It can also be difficult to apply if I keep stepping on the brake on & off, on & off, and so on, then at some point it will be difficult to apply.

The primary indicator that I was looking for was whether it was difficult to apply after just pressing and holding it once. All brakes will get harder to press after each consecutive press when the engine is off. After about 5 presses, it would have lost all it's vacuum. But if yours loses it after holding it on the first press, then that indicates a possible leak.

when u play with the brake pedal your rpm goes up and down?? if its a vacuum leak, your idle will go funny..

The rpm does not go up and down when i play with the brake pedal, but the idle does sound funny only at the first star up of the day.

Do you guys think the vacuum/ brake booster or its hose has a leak? Does it sound like it’s a job for Toyota mechanics? How much $$$ do you guys think it’s going to cost me?

Most cars will be a little different when you start it up, so nothing to worry about there. I would say the leak is not in the vacuum hose itself, but the seal on the diaphragm in the brake booster. When you press on the brakes, one side of the diaphragm is opened up to the atmosphere and sealed from the vacuum while the other side remains under vacuum. If the seal is stuffed, the side that is opened up to the atmosphere will not be sealed fully from the vacuum, hence the whistling sound.

I'm not to sure about how much that is going to cost to replace.

[ussmc]

Out of curiosity, what would happen if I don't get it fix? I'm not a technical person.

Edited March 23, 2009 by ussmc

[coolworld]

i will suggest you to go to workshop of your car.they will give you better solution for it.do it fast otherwise it will become a major problem

[DJKOR]

Out of curiosity, what would happen if I don't get it fix? I'm not a technical person.

Well, all the booster does is give you mechanical advantage for your brakes. By not fixing it, if any other seal goes bust in it, your brakes are going to be hard to apply every time. It just means you will have to apply the brakes harder and most likely increase your stopping distance.

i will suggest you to go to workshop of your car.they will give you better solution for it.do it fast otherwise it will become a major problem

Do you ever have anything a little more useful to say? I'm getting tired of this "take it to the workshop" etc in many of your responses. Sometimes others would like opinions into the issues they are having. It may be something that could easily be resolved, or it may be useful for those that aren't as knowledgeable in cars so that some dealer doesn't try to rip them off. It's like you are building up posts so you can sell something... or really trying to advertise the VW CC.

[ussmc]

Thanks, you've saved me $$$. I was going to take it to Toyota sometime this week, but I'll be taking my time:)

[DJKOR]

Thanks, you've saved me $$$. I was going to take it to Toyota sometime this week, but I'll be taking my time:)

Well don't take too much time eh. After all, your brakes are part of the safety for your car. Without the vacuum booster, it can be quite a bit of force needed to slow the car down. You can never predict what may happen.