My truck is making a jet sound what is that.
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2003 GMC Envoy
Question: jet sound
Answer #1Bret Bodas from RepairPal Test Shop, February 22, 2009, 08:58Master
When the fan clutch goes out, it can make this type of noise.
Where is the noise coming from and when does it occur?
ReplyVisitor, December 19, 2010, 07:25
my envoy is a 2003 and makes that noise but not all the time only if i sit in traffic and then take off and it will do that for a long time does that mean that the fan is bad the clutch fan should not sound like that at any time right
Answer #2tracystark May 10, 2010, 11:24Rookie
i have a 2005 gmc envoy and it is making a jet sound in my truck could u tell me what it is
Answer #3Visitor, May 15, 2010, 11:23
I agree my fan clutch went a few years ago and that is what I decribed the sound of it as to GMC. Also watch out for leaks in your power stearing, that what is going wrong with my 02 Envoy
Answer #4Visitor, August 25, 2010, 21:19
I am the Fan clutch technician who worked for Behr America that is the German company that makes the GMT 360 Fan clutch that is used is this SUV. The jet noise can be one of two things, both being the fan clutch
#1 Could be what is called morning sickness which means the silicone fluid has leaked into the working gaps overnight due to the position the fan sat overnite. This would result in a jet noise for a few minutes after starting the auto and would be intermitted due to different postions it could be in during a "overnite soak"
#2 This would be a constant jet noise due to the silicone fluid that should pump into a reservior when not needed is either not be pumper properly "Something blocking port hole for fluid "or as it is being pumped back into the reservior the valve holding the fluid inside the reservior is stuck open by debree or bad parts made during the production process and would cause the jet noise to be constantly present. In this case your fuel consumption would be greatly reduced and a new Fan Clutch would be needed or the poor gas mileage of always running the clutch when not needed would eat a hole in your wallet. There was a recall of little rubber buttons inside the clutch falling apart and sticking open the Valve lever at one point and it is possible your model has them in the clutch, meaning it should be fixed for free due to the recall issue. This clutch has electronic control which also leaves one other avenue open to why the jet noise may occur due to bad logic in the computer. But if the electronics fail the clutch has a fail off mode meaning with no power going to the clutch it should never turn on at all. Which would cause it to overheat but not make a jet noise.
Brian (former tech for Behr America fan clutch division in Webberville MI ) before the assembly line moved to Dayton Ohio