#%&! Not this!

H

hawk ii

New member
Dec 21, 1998
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Most likely cause -- Exhaust value not seating (stuck
or burned).If the engine runs fairly well
no backfiring thru the carb
no oil blowing out the breather/pvc/oil fill

remove valve cover - turn over engine until both #5
cyc valves are closed

blow air into the #5 spark plug hole --

Have somebady listen at tailpipe -- You will hear it
if it is an exhaust value problem

If you hear it at the carb = intake valve (unlikely)

if you hear it from the oil fill tube = Hole in piston
unlikely

=====
Pete Papas-->http://members.tripod.com/~mehawk_ii/index.html
. ___________ (MY TOYS) (904)672-0571
./_][__][] []| 1973 GMC M/H 1976 Bi-Centennial Harley M/C
.*O-------OO-* Painted Desert 1979 280ZX Datsun (1 of 1000)
Photos--> http://albums.photopoint.com/j/AlbumList?u=192176

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Sorry about the vulgar language.

Just got in from running a compression test on the GMC. When I got her
she ran fine. Got >9 mpg on the run from Illinois. (Forget about the
I-74 incident). Started slow but okay when I moved it back in
December. She has been sitting for 3 months but I have been turning her
over weekly. Didn't start but the electric choke was not attached.
Smelled flooded. Cleaned plugs, all looked about the same. Black and
wet from gasoline.

Results of compression test:
1- 150 2- 132
3- 135 4- 150
5- 0!!! 6- 120
7- 142 8- 149

What could cause the zero reading on #5? I mean nothing, not even a puff
when I held my finger over the hole. I pulled the valve cover and it
appears that the valves are operating, no rattle. I have never worked
on Hydraulic valves so I dont know what to look for.

Could it be a stuck valve?

Would starting it with some Marvel Mystery Oil or Wynns work?

Any suggestions?

Ron and (dont tell) Julie
73 Painted Desert
 
Thanks for the suggestion Pete. You were correct, it is an exhaust
valve. How do I free it up? Crowbar, machine shop or miracle liquid.

Ron and (dont tell her yet) Julie

> Most likely cause -- Exhaust value not seating (stuck
> or burned).If the engine runs fairly well
> no backfiring thru the carb
> no oil blowing out the breather/pvc/oil fill
>
> remove valve cover - turn over engine until both #5
> cyc valves are closed
>
> blow air into the #5 spark plug hole --
>
> Have somebady listen at tailpipe -- You will hear it
> if it is an exhaust value problem
>
> If you hear it at the carb = intake valve (unlikely)
>
> if you hear it from the oil fill tube = Hole in piston
> unlikely
>
> =====
> Pete Papas-->http://members.tripod.com/~mehawk_ii/index.html
> . ___________ (MY TOYS) (904)672-0571
> ./_][__][] []| 1973 GMC M/H 1976 Bi-Centennial Harley M/C
> .*O-------OO-* Painted Desert 1979 280ZX Datsun (1 of 1000)
> Photos--> http://albums.photopoint.com/j/AlbumList?u=192176
>
> __________________________________________________
> Do You Yahoo!?
> Talk to your friends online with Yahoo! Messenger.
> http://im.yahoo.com
 
Thanks for the suggestion Pete. You were correct, it is an exhaust
valve. How do I free it up? Crowbar, machine shop or miracle liquid.

Ron and (dont tell her yet) Julie

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
 
> Thanks for the suggestion Pete. You were correct, it is an exhaust
> valve. How do I free it up? Crowbar, machine shop or miracle liquid.
>
> Ron and (dont tell her yet) Julie
>

>
> > Most likely cause -- Exhaust value not seating (stuck
> > or burned).If the engine runs fairly well
> > no backfiring thru the carb
> > no oil blowing out the breather/pvc/oil fill
> >
> > remove valve cover - turn over engine until both #5
> > cyc valves are closed
> >
> > blow air into the #5 spark plug hole --
> >
> > Have somebady listen at tailpipe -- You will hear it
> > if it is an exhaust value problem
> >
> > If you hear it at the carb = intake valve (unlikely)
> >
> > if you hear it from the oil fill tube = Hole in piston
> > unlikely
> >
> > =====
> > Pete Papas-->http://members.tripod.com/~mehawk_ii/index.html
> > . ___________ (MY TOYS) (904)672-0571
> > ./_][__][] []| 1973 GMC M/H 1976 Bi-Centennial Harley M/C
> > .*O-------OO-* Painted Desert 1979 280ZX Datsun (1 of 1000)
> > Photos--> http://albums.photopoint.com/j/AlbumList?u=192176
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Talk to your friends online with Yahoo! Messenger.
> > http://im.yahoo.com

Try a bottle of Wynn's Tune-up befor you go and spend a lot of money. It
is super for disolving gums and varnishes and getting valves to working
properly. If you can't find it locally, call 1-800-645-8108 and they will
tell you where there is a Distributor.


- --
Wayne

*****************************************************************
WAYNE NEWLAND Phones 301-596-2484
6506 Spring Plow Lane 410-995-6629
Columbia, Maryland 21045-4650 Fax 410-381-3013

E-Mail: wayne

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ON THE ROAD AGAIN!
F9300
1975 Palm Beach
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Did you remove the rockers to do this or did you have to pull the head?

RON

> Hey Ron;
>
> When my brother and I brought his Palm Beach back to life a few months
> ago, it had 6 stuck valves. We used about half a can of Kroil during the
> process of closing the valves with a tie-rod tool, the tapping them open
> with a ball peen hammer. Took about 2 hours, but got them all loose. Put the
> valve covers on, added some Marvelous Myster Oil to the oil change, and he
> drove it from Bakersfield, Ca. to Prosser Wa. over the next 4 days with a 2
> day layover in Manteca, Ca. (my place) to do some interior work. The Kroil
> worked wonders.
>
> GaryB
> 76 PB in Ca.
>
> Date: Mon, 03 Apr 2000 15:29:38 -0400
> From: RONALD KAZI
> Subject: Re: GMC: #%&! Not this!
>
> Thanks for the suggestion Pete. You were correct, it is an exhaust
> valve. How do I free it up? Crowbar, machine shop or miracle liquid.
>
> Ron and (dont tell her yet) Julie
>
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
 
Well, I put in a quart of Marvel Mystery Oil, squirted some Kroil down
the valve guides, crossed my fingers and petted Skippy the Dog for
luck. Fired that baby up and she ran. Rough at first. Reved her up
and let her run for about 20 minutes. Runs like new. Let her sit for a
couple of hours. Started immediately.

Rechecked the compression. All are between 135 and 150. I assume this
is a good thing. What is a typical compression on the GMC?

One step closer to hitting the road.

Ron and (I already told) Julie
 
I had a hole in my #7 exaust valve when I purchased my GM the hole was as
big as a pencil. " 0" compression.

I bought my rig from the Biggest Liar in Washington.

Gary 76 Glen Duvall WA.
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> Rechecked the compression. All are between 135 and 150. I assume
> this
> is a good thing. What is a typical compression on the GMC?
>
> One step closer to hitting the road.
>
> Ron and (I already told) Julie
>
When I last did mine, they all ran between 150 and 155 except for #8
which was 145.

I recall reading something in the shop manual (I think) that says they
should be relatively even and within a percentage but I guess none of
this helps. Maybe Skippy the Dog knows about this! :)

David Lee Greenberg
GMC Motorhome Registry
Dedicated to the preservation of the Classic GMC
http://www.gmcss.com/registry.htm
 
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