I manage a grabage service, have a 2009 freight with cummins 8.3 Isc. Today it stared whistling, I checked the intake plumbing but didn't see any cracks in flex tubing or loose clamps. Its actually pretty loud while under load. I'm gonna loosen the clamps on flex tubing and spin them around so I can check the back sides. Has 50,000 miles. Also earlier this winter message center said to do manual regen but it was not enabled, truck went into shutdown, had it towed to Freight daeler, PDF was plugged , they had it cleaned did upate to ECM, now the guys are telling me it does regen bout every day. Any ideas on the whistling, and anyone else having problems with the ISC? Any info is appreciated.

 

A leak in the lines will cause loss of boost and generally causes more than normal black smoke in the exhaust. Sometime it can be very difficult to find a cooling leak if its not under pressure. There are ways to make your own pressure cap to pressurize the cooling system with a small air compressor.

 

don't confuse the guy brother

inter COOLING system not your h2o cooling system

also here is a tip. on the 6.7's that are in our trucks, a loud whistle will be heard if the EGR cooler gasket between the cooler and manifold is leaking.

 

Could not find a leak, but when it did another regen the whistling quit after regen. Not sure what caused it, gonna call cummins again, thanks for replies.