Turbo E-brake Noise

[waco kid]

I have a 400 ISL (built in late 2006) Just lately my wife has been hearing a high pitched noise, a whistle or squeal, coming from the engine area, I'm half deaf so I do not hear it. The only time she hears it is when I'm accelerating and the turbo boost passes the 25 mark while on its way to 30, she only hears it for about 2 or 3 seconds. If I'm pulling a small hill and the boost goes to 25 or 26 she does not hear it, its only heard while passing the 25 mark while on its way to full boost. She also hears it for a second or two when the exhaust brake comes on (cummins e-brake). Before I pay cummins a bunch of money to look around in there maybe some one hear can tell me where to look. Is there a relief valve or something in the the area of the turbo? All other functions are fine, fuel mileage has not changed and it still pulls the hills with plenty of power. Thanks, Bruce.....

[Darrel]

I had a similar problem with my ISL. It eventually got bad enough to find and was a leak in the pipe connections between the turbo and Intake manifold. New P-clamp and pipe adjustment fixed it. Hope your problem is as easy.

Have anice day - Darrel

[Wayne R]

Time to get dirty Bruce and tighten those clamps!

[waco kid]

Thanks Wayne, Maybe I could buy Sandy some ear plugs since shes the only one that hears it.....Bruce

[bthomforde]

Had a similar noise on our 2008 ISL 400, turned out to be a blown exhaust gasket, luckily it was still under warranty.

[JCM]

Had the same thing about 1 month ago. It was a blown exhaust gasket.
It was still under warantee. A 2006 engine. Cummins warantee is 5 years on a RV engine.
Much quieter now.

[Skip426]

Quote:

Originally Posted by bthomforde Had a similar noise on our 2008 ISL 400, turned out to be a blown exhaust gasket, luckily it was still under warranty.

Exhaust gasket get my vote too,back pressure in the manifold increases as turbo builds towards max, and fades when the wastegate opens. Look carefully around each exhaust flange on the head and the manifold to turbo flange, you'll need a mirror and a flash light, look for carbon traces, and or broken flange bolts.