High pitch whistle????

[smokeum99ta]

My truck just recently started making a really high pitch whistle. I'm pretty sure it from some sort of boost leak but where should I be looking for it? I've just replaced all four inter cooler boots and it's the same. I noticed that there's is some black soot around the upper inter cooler boot by the turbo. But can't seem to find where it's coming from. Any ideas?


Also my egts are higher now and mpg are down.

[jimmyv13]

Sounds like an up pipe or y pipe leak. Put your hands around there in a cold start and you'll feel the air rushing out. The flex and bellows are known problem areas.