I have a 2017 Kenworth T680 with a Cummins ISX 15 550 hp engine. I have a whistle in my turbo. The whistle is at idle and with increased RPMs. What's weird is, it goes quiet after about 10 minutes at idle. I also noticed, while it's whistling at idle, my idle usage shows 2 gal/hr. But when it shuts up, idle usage goes down to .8 gal/hr. Neither I nor several mechanics can find an exhaust leak. Turbo is dry, with no play, and turbo psi is working normally. ( 20 psi on small grades up to 40 psi on large grades depending on the load). After long periods of driving, when I come to a stop, sometimes it will be squealing other times it won't. This is driving me insane. When it squeals, it is so loud you can here it across the parking lot. Not a single mechanic I've taken it to can figure it out. Thanks in advance!
Is this truck egr deleted? Might be switching to the wrong operating mode. Trying to warm up a non existing SCR can
You likely have a cracked exhaust manifold gasket just starting to leak. When the turbo changes exhaust back pressure the noise can change and or go away. the noise is the exhaust leaking by the bi-metal manifold gaskets as they are cracked and vibrating. Inspect closely for small soot trails exiting the manifold at the cylinder head. Most often #2 or #5 but could be others as well. Find a shop with a smoke machine and leak check the hot side of the engine and the leak will show its face.
I see some staining on the EGR pipe. Looks like something may be leaking from above out of the picture. Nothing immediately concerning that I can see. Truck repairs are expensive. Most dealer door rates are closing in on or at 200hr. What area do you frequent?
