When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I had the similar issue. It turned out to be a crack in the plastic CAC pipe.
Same here, sounded like air squealing out of a balloon. Turned out to be small cracks between the corrugations on the bellows part of the lower CAC tube.
I had the similar issue. It turned out to be a crack in the plastic CAC pipe.
Originally Posted by Rusty Axlerod
Same here, sounded like air squealing out of a balloon. Turned out to be small cracks between the corrugations on the bellows part of the lower CAC tube.
This is what I'm thinking it is. It didn't start happening until after I had fixed the harness from the squirrels that used my engine compartment as a nursery. I'm thinking it's either the charged side or the intake side being brought under heavy vacuum when the turbo is spinning up. I need to pull it all apart again and see if it's something obvious or just get new boots as they're all original and probably need replaced anyway.
The cap vents around 15-16 psi. If you reach that pressure, then the sound you hear is likely to be the cap venting pressure. Most likely source of this (if you have it) is a leaking head gasket.
It’s very likely if your degas bottle cap is venting you’ll have coolant residue under the hood. This is also a good tell tale. Check the exhaust bellows as well. These are prone to crack. The tell tale for this is carbon/ soot on the bellow itself or on the firewall behind the engine. In some cases, cracked up pipes can cause a squeal at higher RPM.
It did it all the way into town yesterday. I stopped in a parking lot, shifted the intake boot around and it hasn't done it since. I've got a new intake boot on order.