Strange Engine Noise During Startup Prado 150 2014 GXL (Video with sound Included)

[aadipuri Lurker Find all posts View Profile Close aadipuri]

Hi Guys - recently my Prado been acting up and generating hissing noise only during startup. It disappears during idling and sometimes came back during climbing. I have recorded the peculiar noise here (also whining sound when turning off engine):

https://www.youtube.com/watch?v=wVmbTKYeg4M

Any idea what is the hissing sound during start up? Compression sound? Vacuum leaks ?

Btw, the engine oil is slightly overfilled

Thanks mate

[snapper49 Member Find all posts View Profile Close snapper49]

Try putting some soap on the fan belt

[bignick Lurker Find all posts View Profile Close bignick]

Definitely sounds like a belt. Give the soap or some stop squeak a try. How's the tension on the belt? Can you see its condition/how low it's sitting in the pulleysor know when it was last replaced?

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

I had the same on my 120 series 1kd at around 200 000km. After changing belt and pulleys, found out it was the alternator. The over ride clutch built into the alternator pulley was failing. You can buy a pulley and replacement tool but you might be better off just getting a new alternator. I ended up getting an OEX high output unit. It was still working fine when I sold the car at 255 000km.