Yahoo Message Number: 82150 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/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
Yahoo Message Number: 82153 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/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
Yahoo Message Number: 82158 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/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
Yahoo Message Number: 82166 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/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
Yahoo Message Number: 82187 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/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
Yahoo Message Number: 82189 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/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
Yahoo Message Number: 82219 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/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