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Topic: HISSING ENGINE SOUND - EXHAUST BRAKE?? (Read 2157 times) previous topic - next topic
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HISSING ENGINE SOUND - EXHAUST BRAKE??

Yahoo Message Number: 82150
We first noticed a hissing sound from our engine when the exhaust brake was engaged. We next noticed the hissing sound when we were accelerating. We read a prior post from 2006 about the ISC engine from a 2005 Inspire (I'm assuming a 350 ISC) and a 'common' problem with either the manifold or the exhaust brake. We have an appointment with a Cummings place tomorrow. Has anyone had or know the seriousness of this problem?

Clint Frederick 2004 Inspire #51038

Re: HISSING ENGINE SOUND - EXHAUST BRAKE??

Reply #1 –
Yahoo Message Number: 82153
Clint, if you have a SilverLeaf in coach push the Diagnostic Button and scroll to see if you any fault codes?
ISC & ISL Cummins have a common problem with cracked Exhaust Manifolds but can't imagine you'd hear a hissing sound, you would however notice a lack of power and a different sound than the usual from muffler.
If it is the Exhaust Manifold make sure you replace both pieces of the manifold with new bolts & gasket.

To me the hissing sound could be related to an air hose problem.

Hope it's something simple for you.

Mike 03 Allure 1st Ave. #30898 ISL

Re: HISSING ENGINE SOUND - EXHAUST BRAKE??

Reply #2 –
Yahoo Message Number: 82158
Clint,

If you have Pac Brake, it is is air actuated. Have you checked the air coupling and hose that feeds the exhaust brake? Daron Hairabedian, 98 Allure, 30226

Re: HISSING ENGINE SOUND - EXHAUST BRAKE??

Reply #3 –
Yahoo Message Number: 82166
Thanks for the information - we don't have Silverleaf - have not noticed a reduction in power - guess we will find the problem tomorrow -

Clint Frederick 2004 Inspire 51038

Re: HISSING ENGINE SOUND - EXHAUST BRAKE??

Reply #4 –
Yahoo Message Number: 82187
Information on the 'hissing sound'. Black soot around the 4th Cylinder - the tech said he would order the gasket thinking that would solve the problem. Told him of the email from this group recommending replacement of both manifolds - that it apparently is a problem. Total parts cost is about $600 for both manifolds and the gaskets (Manifold cost is $277 and $132) - said to order the parts. Next question - if this is a problem with the 350 ISC engine why was there not a recall - do they still cover the cost? According to my Good Sam if it is just a gasket not covered - if manifold crack it is covered.

Clint Frederick 2004 Inspire #51038

Re: HISSING ENGINE SOUND - EXHAUST BRAKE??

Reply #5 –
Yahoo Message Number: 82189
Clint,

Cracked manifolds on the 350 ISC is a common, known problem. In May of '11, I got in on the tail end of an engine compressor recall (10 yrs. old). They found 2 cracked manifolds on mine at that time. Cummins covered the compressor but not the manifolds.

Dave Trotter

01 Intrigue 11215 w/350 ISC
 

Re: HISSING ENGINE SOUND - EXHAUST BRAKE??

Reply #6 –
Yahoo Message Number: 82219
Actually, a hissing sound is exactly what you can hear with a cracked manifold. I had a cracked manifold on my sob and it was coming from the exhaust manifold crack between #5 and #6 cylinders. When the pac brake is engaged the engine becomes essentally a big air compressor and the crack becomes a high pressure air leak. If the crack is bad enough I can imagine under throttle you could get the same effect.

Dave

aka Billy Byte (trusty hound)
2000 Allure #30443