6 months, still no help from mechanics.

[dindy]

first of all happy christmas from malta, i got a sicky issue. spent alot on my vitz for idle issue. im thinking of selling it now, no help and no improvment due idle control valve, spark plugs, air flow meter, changed and original. as im driving no trouble at all!!!! but as i stop on drive position and hold by pressing the brake , it comes really shaky when on idle!!! almost wanna trun off. but if i put it on normal (free) and press the brake no shakes. then as i select drive, it shakes and vibrate......always with the brake pressed..... im getting sick of this issue. no one can find whats wrong. no codes. i will be very happy if you can assist me on this issue. before i have to say bye to my toyota. (1.0 auto 4 cylinder):iono:

[CTScott]

A while back, via PM, we discussed my theory, which is the torque converter of the automatic transmission being the likely cause. Did you ever discuss that with your mechanic?

[dindy]

yeap told them about that, i remeber what you told me. believe me or not, everyone is afaraid of open my gearbox off. one mechanic told me it could be automatic gear oil is wrong. i must give up on mechanics and go to a toyota service factory. not a nice choice for money but i guess they will do find out.

[CoryM]

When it is shaking try this:

Pull parking brake (hand brake) on and release the brake pedal while transmission is in Drive. Does it shake then? If not, press the brake pedal, does it shake now?

The reason I ask is because the brake booster uses engine vacuum to operate. If it is leaking, the engine pull in more air than it expects, and it will go lean. It's possible for these to leak ONLY while the brake pedal is depressed. Often can hear a hissing from underdash when they do.

Cheers.

[Kens]

Hello Dindy! If you want, I have a very reliable mechanic that you can use. He has helped me in many situations and he may be able to assist you. Would you like his number?

[dindy]

i did that cory...when in drive position with handbrake only, no shakes!! but as i press the brake it shakes, yes. so you mean i need to check the brake system?

[dindy]

and where is the possible air leak in the system?

[CoryM]

i did that cory...when in drive position with handbrake only, no shakes!! but as i press the brake it shakes, yes. so you mean i need to check the brake system?

Excellent. Looks like we are getting somewhere.
The brake booster is the black drum that the brake master cylinder bolts onto (where you put brake fluid in). The brake booster makes it so you only have to press gently on the brake pedal to stop the car. It uses engine vacuum to do this. There is a black rubber hose that comes from the engine and goes to the booster. About 13mm thick. The next step is to remove this hose from the booster (where the yellow arrow points) and plug it with a bolt (so it is sealed). Now start the car and drive it around to see if it shakes. WARNING: It is safe to drive the car like this, but you will have to press the brake pedal MUCH harder to stop the car. Drive carefully until you are comfortable.

If the engine does not shake, replace the brake booster. It is leaking.

Cheers.

[CTScott]

i did that cory...when in drive position with handbrake only, no shakes!! but as i press the brake it shakes, yes. so you mean i need to check the brake system?

Great thought by CoryM - That is a far simpler issue to deal with than a bad torque converter.

The brake booster is the round device that the brake master cylinder (where you would add brake fluid) is mounted to.

[dindy]

hell youer awesome :). i will try that asap, since im sick in the bed right now...i forgot to tell you some thing, the problem begans about 7 months ago while i was driving and suddenly i pressed to brake it my car it looks like wanna stop at all!!
but it did 3 times and no trouble with stoping, but sure there where it began the shaky trouble. guys thanks really for tell me, i will let you know later about how it goes..