Help deciding on a buy

thomas phipps

New member
Dec 29, 2005
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exhaust fumes inside the cabin are never a good thing. Sounds like exhaust leaks between the exhaust manifolds and the heads. look, as much as
possible, for obvious exhaust leak evidence around the manifolds.
since your question sounds like you do not own this one yet, the fastest fix may be to remove the exhaust manifolds, clean the surfaces, and
re-install with remflex gaskets. search the forum for remflex and follow the install directions exactly.
of course, the coach may have a rusted out exhaust system. easy enough to replace.
headers on the GMC are used because the passenger side exhaust manifold for the 455 are not available as new old stock. they do not seem to add any
additional power.
TOM
--
2012 Phoenix Cruiser model 2552
KA4CSG
 
Tom,
You are correct that one does not gain much just by installing headers as
they are designed to work with 2.5Dia muffler with 3" mandrel bent pipes.
We find when we match these Low RPM Headers with the right combination
exhaust system, you will notice improved performance.
I know Miguel of MGM GMC and I are sold on the system.

On Sun, Jun 2, 2019 at 7:12 PM Thomas Phipps via Gmclist <

> exhaust fumes inside the cabin are never a good thing. Sounds like exhaust
> leaks between the exhaust manifolds and the heads. look, as much as
> possible, for obvious exhaust leak evidence around the manifolds.
> since your question sounds like you do not own this one yet, the fastest
> fix may be to remove the exhaust manifolds, clean the surfaces, and
> re-install with remflex gaskets. search the forum for remflex and follow
> the install directions exactly.
> of course, the coach may have a rusted out exhaust system. easy enough to
> replace.
> headers on the GMC are used because the passenger side exhaust manifold
> for the 455 are not available as new old stock. they do not seem to add any
> additional power.
> TOM
> --
> 2012 Phoenix Cruiser model 2552
> KA4CSG
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
The transmission is probably not kicking down as someone may have disconnected the electrical kick down or broken the switch on the gas pedal arm.
Also if it's been sitting, and not fully warmed up the secondary air valve is most likely stuck or still engaged and not opening because the choke is
not fully open. You will just be on the small carb primaries on the Qjet. Also most of these need a throttle cable adjustment to pull the throttle
wide open. The secondaries don't open until the last 1/3 or so of pedal travel so cable must be set correctly.
If you dont' hear an exhaust leak up front, you don't have one. It you have one you will hear it. A drop or 2 of fuel or oil burning off will make you
think you have major fumes. If it's been sitting this may be the case. If it has been sitting and smoke is blue, owner may have fogged engine (not
likely) or a couple drops of oil have slid down the valve guides and are burning off. If engine has no ticks or knocks, it's usually good engine. See
if smoke goes away after a drive circuit. If smoke is white it's coolant and there are bigger issues.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
stink is not normal..... but these are old and exhaust systems leak, and oil leaks if not addressed. All repairable.

without towing, it should accelerate decent enough. it should also climb and drive 60-70MPH easy enough. sounds like there are some issues.

Headers are a good route, but I know a few that stick with Manifolds. I know a couple that have gotten what seem to be new manifolds from
cinnabar.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
Congrats!
When I bought mine it didn't want to shift out of 2nd and took forever to get up to speed etc.
A few hours and some advice from here and I was up and running as intended.
Now I can cruise at 80 all day if I want to and get there quickly(-ish).
--
Justin Brady
http://www.thegmcrv.com/
1976 Palm Beach 455