Here's the tally -
I received 73 responses from a total of 32 folks. That represents 23
coaches. (some did not supply information about their coach) 8 of us had
cracked manifolds. 15 had exhaust leaks at either the manifold or the donut
seal. Interestingly enough, 8 of the folks who reported gasket problems had
to replace gaskets at least twice in a 20k mile period. One person has
horrible luck - replaced gaskets every 5k miles (or less).
For those who had cracked manifolds, half replaced their manifolds with
headers.
Cracks mostly developed in the center of the manifold with both sides
having equal numbers of failures. Exhaust manifold leaks had no particular
area that leaked more than another.
There is no consensus of what type of gasket to use (if any). Gaskets that
worked on one coach failed repeatedly on another.
Several theories have been proposed for the cracking and leak problems
encountered. Emery Stora suggested that the leaning of the mixture due to
reformulated gas may be causing the the exhaust to run hotter, contributing
to leaks and cracks.
Stay tuned.
Henry
Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (831) 462-5199 / full service marketing
fax: (831) 462-5198
http://www.henry-davis.com/ http://www.henry-davis.com
I received 73 responses from a total of 32 folks. That represents 23
coaches. (some did not supply information about their coach) 8 of us had
cracked manifolds. 15 had exhaust leaks at either the manifold or the donut
seal. Interestingly enough, 8 of the folks who reported gasket problems had
to replace gaskets at least twice in a 20k mile period. One person has
horrible luck - replaced gaskets every 5k miles (or less).
For those who had cracked manifolds, half replaced their manifolds with
headers.
Cracks mostly developed in the center of the manifold with both sides
having equal numbers of failures. Exhaust manifold leaks had no particular
area that leaked more than another.
There is no consensus of what type of gasket to use (if any). Gaskets that
worked on one coach failed repeatedly on another.
Several theories have been proposed for the cracking and leak problems
encountered. Emery Stora suggested that the leaning of the mixture due to
reformulated gas may be causing the the exhaust to run hotter, contributing
to leaks and cracks.
Stay tuned.
Henry
Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (831) 462-5199 / full service marketing
fax: (831) 462-5198
http://www.henry-davis.com/ http://www.henry-davis.com
