I have a 2007 LBZ and I have a high pitched squeal noise under my hood next to the firewall. For some reason my turbo veins cycle at about 1500 when I'm driving down the road instead of at idle (probably poor tuning). But when the veins do close, it causes this squealing noise to appear. It sounds like it's in my dash on the drivers side. The noise disappears after the veins open back up and won't appear again for the rest of the trip. It only happens when it's cold outside, in the summer this isn't a problem. Sometimes I can replicate the sound if I rev my truck up to around 2500 rpm in park. It won't always do it though so it makes it very frustrating. I tightened all my intercooler boots, checked for exhaust leaks on my u pipes and found nothing. Anything else I should check? Anyone else have this problem?
