I replaced mine at 180K and really had very little wear, but I had the
engine apart anyways, so I changed it... since it was only lilke $15 for the
chain and gears at Autozone I figured why not...
Tony.
www.helptonyout.com
----- Original Message -----
From: Wilbur <bwgreen@ocean.otr.usm.edu>
To: <dakota-truck-moderator@bent.twistedbits.net>
Sent: Saturday, January 24, 2004 5:52 PM
Subject: Re: DML: replacing timing chain on 1998 dakota 2.5 liter
>
> Hey Guys,
>
> Just wanted to say thanks again. I replaced the broken valve spring and
> tested compression on the cylinder...it was around 150 psi...buttoned
> everything back up and she runs like a champ again. You guys saved me
> from the expense of a timing chain, sprockets and gaskets.
>
> BTW, out of curiosity, what is the average life of a timing chain on the
> 4 cylinder 2.5L Daks? It seems to me it should have lasted more than
> 100,000 miles (thats when it was changed out--supposedly had gone bad).
> I guess I could open it up and look at it...but how exactly would I
> tell wear on it? Looseness? Oh well, have a good weekend!
>
> Wilbur
>
>
>
> Wilbur wrote:
> >
> > That would be good. :) It would definitely make the job easier. I had
> > to order the valve springs...none of the local parts places or the dodge
> > dealership had any in stock...So the Dodge dealership is ordering some
> > from Dallas, I think.
> >
> > FYI, when I started taking things apart, I noticed that the CCV vacuum
> > tube was broken...so I had the dealership order one of those too...they
> > had to order that little item from Detroit. :) I wonder why the 2.5L
> > have a CCV (Crank Case Ventilation) vacuum tube instead of a PCV valve
> > like the larger engines?
> >
> > Oh well....supposedly all the parts will be in by next friday so I will
> > proceed at that time to replace the valve spring...Thanks for all the
> > help guys--Cross your fingers and say a prayer for me. Hopefully this
> > will bring my baby back to working order for a bit. You guys are really
> > a great bunch of people. :) I'll let you know how it goes. Have a
> > great weekend guys!
> >
> > Wilbur
> >
> >
> >
> >
> >
> > Aaron Wyse wrote:
> >
> >> 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.
> >>>>>>
> >>>>>
> >>
> >
>
>
This archive was generated by hypermail 2b29 : Sun Feb 01 2004 - 16:29:51 EST