The Trucks a 2017 Cascadia with a DD13. At higher RPMs above 1500, it gets a loud screeching noise. It’s consistently the same, I think it’s a heat shield on the turbo. Sounds terrible. Don’t think it’s anything serious. Let off fuel, it stops. Turn on jakes it starts doing it again. Anyone ever had this or a similar problem? If so what was the cause?
Check for air leaks in the air to air cooler system. A large pinhole sized hole can be almost silent until pressure climbs. High rpms or jakes will be when the pressure is highest.
It sounds like metal to metal. Like the turbo fins hitting. That’s what I’m worried about. I originally wrote it off as nothing serious. Thought it was a clutch or a flywheel noise. I think it’s definitely on the engine near turbo. I’ll check the boots. Makes sense because it goes away as soon as I let off the fuel.
Pull the boot off the turbo going to the CAC. Look at the housing and see if the turbo fins are rubbing. Grab the end and move side to side and forward and back to check for play. If the boots and turbo are good I would consider the belt(s) as in slipping, possibly a bearing.
I had what I thought was a air to air leak starting . I explained to our mechanic he agreed that it was ok to finish trip . Noise got louder and I noticed trans temp climbing fast on pulls 3 hrs later trans came apart . The oil cooler line rubbed through but no oil was on front of trailer or catwalk area. Apparently this was the 3rd truck in 2 years this happened on in the fleet all 2016/17 models. PS I complained about a engine oil leak but it was obviously the trans oil line.
Western Stars, at least the car hauler chassis, are notorious for this right where the lines cross at the back of the radiator
Good advice. Whatever the noise, it only happens at a certain time. Something rubbing, or a bearing. The engineers call it vibration frequency. Recently had a conversation with a mechanical engineer. The testing they do to find the frequency of parts, redesigning them, so the frequency is higher than needed. It’s really cool stuff. Has to do with thickness, type, and design of parts. I think I’ll take the heat shield off the turbo for a day or two. See if it goes away. All these newer engines vibrate so much. Rough idles, especially. Like they’re out of balance. If my series 60 idled like that I’d be very worried.
