Weird engineer noise

[TheGreenToad]

hi all,

I am new so be gentle

1997 - SR5 4Runner. 85,000 miles tip top condition with 1 annoying exception.


The following happened randomly but most likely can be reproduced as follow.

After the vehicle runs for more than 3 miles (completely warmed), it "may" produce a honk noise under the left side under the hood. I noise comes when I step on the gas pedal. The noise sounds like people honking on me 2 cars away not very loud but I can hear it. In fact, my wife said it does sounds like people honks from 2 cars away and caused her to check around who was the bada$$. It sounds like eeeekkk eeeeeekk. Hope you know what i meant. The noise cannot be heard from outside the car - at least not as obvious. I thought they were belts so I have Toyota dealer replaced all the V-belts and sounds still proceed. I cannot 100% reproduced the issue so this is very hard for me to show it to the toyota dealer.

Thanks,
greenFrog

 

[Her4Runner]

Kinda new to the 4Runner game myself, but sounds like a vacuum leak. I know on my GMC Syclone or Typhoon the "honking" noise you describe can be linked to a faulty brake booster valve.

As far as I can tell, the 4R doesn't have a brake booster valve per se, but there is a large diameter vac. line feeding the brake booster. Might check there as a leak in a smaller diameter vac. line tends to produce more of a whistling sound.

HTH,
Her4Runner

 

[TheGreenToad]

HTH,

Thank you for the suggestion.

I do not see any leaks on my brake and been inspected by Toyota dealer 3 days ago and they do not even considered to have those brake pads to be replaced.

As far as I can see, I do not see any sort of leaking under the hood.

Any other suggestion or any better way to tell where the noise coming from?

The noise only comes on when I step on the gas pedal.

 

[TheGreenToad]

HTH,

Thank you for the suggestion.

I do not see any leaks on my brake and been inspected by Toyota dealer 3 days ago and they do not even considered to have those brake pads to be replaced.

As far as I can see, I do not see any sort of leaking under the hood.

Any other suggestion or any better way to tell where the noise coming from?

The noise only comes on when I step on the gas pedal.