at TDC.. maybe 3/4 inch max.. just my ballpark guess.. The cyl head pockets
can't be that big.
Aaron
----- Original Message -----
From: "Wilbur" <bwgreen@ocean.otr.usm.edu>
To: <dakota-truck-moderator@bent.twistedbits.net>
Sent: Thursday, January 15, 2004 10:59 PM
Subject: Re: DML: replacing timing chain on 1998 dakota 2.5 liter
>
> Yeah I think I will start with replacing the one bad spring and go from
> there...I wonder...at TDC, how far would the valve "fall" in if I were
> to replace the spring and I was unable to keep hold of the valve stem?
> Would it fall far enough in that I could not reach it or would enough of
> the valve stem be sticking up to pull it back up? just curious.
>
> Wilbur
>
>
>
> Aaron Wyse wrote:
> > another way to hold the valve up is to fill the cylinder with a rope (at
> > BDC) and then then give the crank a little bump to compress it a little.
> >
> > Personally.. I would just replace the one bad spring.. then do another
> > compression test. If all is well. Drive it another 50K miles or so
before
> > I worry about anything else. Since a valve spring should not have
broken in
> > the first place, assume it as more of a fluke break than an actual high
> > mileage problem. Make sure you do a couple of oil change fairlu close
> > together.. just in case any particles of spring are circulating around
in
> > there.
> > Otherwise.. The valve may have actually damaged something that will
require
> > more work. And you'll need to go in deeper.
> > Also.. glad you found the problem
> > Just my opinions.
> > Aaron Wyse
> >
> >
> > ----- Original Message -----
> > From: "Wilbur" <bwgreen@ocean.otr.usm.edu>
> > To: <dakota-truck-moderator@bent.twistedbits.net>
> > Sent: Thursday, January 15, 2004 4:00 PM
> > Subject: Re: DML: replacing timing chain on 1998 dakota 2.5 liter
> >
> >
> >
> >>You bet I will. :) Ok currently....I put cyl #1 to TDC and injected
> >>air into sparkplug opening....heard air hissing in valve cover...So
> >>removed valve cover, and wahlah, i see the first valve at the front of
> >>the engine (facing the fan and radiator) has a busted spring. I am not
> >>sure if that one is the intake or exhaust valve spring, just that it is
> >>the first one in line. The valve has not dropped...it is still
> >>attached. The valve still could have "kissed" the piston, so to speak.
> >> So sounds like i need to replace that spring at the very least...and I
> >>suppose I should replace the other one of the pair too? Should I
> >>replace all the valve springs and and locks and retainers and valve stem
> >>oil seals for all 4 cylinders or just for cyl #1?
> >>
> >>The push rods looked okay from cyl #1, not bent or anything and I have
> >>the rockers, bridge and pivot assembly and bolts (also looked fine)
> >>sitting in a box in the correct order to put back on.
> >>
> >>As for replacing the valve springs...from what i can see online, some
> >>peeps recommend using air pressure via the spark plug hole to keep the
> >>valve seated while taking off the spring....I don't have an air
> >>compressor at all to maintain the recommended pressure (90psi) to keep
> >>the valve seated. Any other recommendations to keep the valve seated
> >>while I remove the spring? Could I tie some string to the valve stem
> >>after I have it compressed to keep it from falling into the cylinder?
> >>Oh and do the valve compressors you can get at autozone and O'reillys
> >>work for this kind of job? Thanks.
> >>
> >>Wilbur
> >>
> >>
> >>
> >>
> >>Josh Battles wrote:
> >>
> >>>""Rick Barnes"" <barnesrv@comcast.net> wrote in message
> >>>
> >>>
> >>>>Josh,
> >>>>
> >>>>You blew a ring for that very reason..once you did the great valve
job,
> >>>
> >>>you
> >>>
> >>>
> >>>>increased the compression in the cylinder and the weakened rings could
> >
> > not
> >
> >>>>hold the increased compression..viola, broken rings...common, and your
> >>>>advice is right on, (in my humble opinion). If you do a valve job, at
> >>>
> >>>least
> >>>
> >>>
> >>>>replace the rings too.
> >>>>
> >>>>Rascal
> >>>
> >>>
> >>>that's what my uncle told me... (ase master certified mechanic) after
> >
> > the
> >
> >>>fact, and while he was helping me replace the rings and smooth out the
> >>>slight cylinder wall scoring. If I was gonna do it now, I'd do it all
> >
> > at
> >
> >>>once and save myself the extra headache later on.
> >>>
> >>>learn from our mistakes Wilbur! If you end up having to have valves
> >
> > done,
> >
> >>>do the rings now too so you don't have to do them later.
> >>>
> >>
> >
>
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