Vacuum leak noise aroud the throttle body only on idle

st185_cs

New member
Hello.

My st185 CS has been in the garage for about 6 months because of a faulty alternator and engine wire harness.

I fixed this during the weekend, but now i have another problem after i assembled the car again.

There is a noise simillar to a vacuum leak around the throttle body/intake manifold. The car makes only this noise at idle. If pull the throttle cable a bit, the noise disappears. The engine runs ok, but when it warms the idle goes too low and the engine almost stalls.

i have checked all the vacuum hoses and everything appears to be ok. The noise comes out from the area next to the throttle cable end. I dont know if this noise is normal or not.

any help? will upload a video as soon as possible.
 

masco

New member
Sometimes after sitting the idle valve (ISV ISCV IACV whatever you want to call it) can get stuck or sticky. So the change in sound/idle characteristics is likely due to that. I suggest cleaning it out with your favorite cleaner product and see if you can get it to free up. In my experience clean ST185's sound like they have a vacuum leak at idle, which is just that valve opening up to do its job.

If you still suspect you have have a vacuum leak try spraying a brake cleaner or some cleaner product around the source of the sound at idle. If you hear the idle speed change (generally rises) then you have found your leak.
 

Gibs

New member
Going to try that. My ST185 has been sitting for 4 years now and now that it is running I also have a whistle sound. Going to try to clean the ISV. Thanks
 
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