You don't really want to push them far beyond that.. I'm sure many have run
them closer to 200K miles or better; but the more miles you try to get out
of it, the bigger chance you have of it letting go on you as well.
Glad to hear that was all it needed.. I bet that spring was cheaper than
tearing everything apart also.
Aaron Wyse
----- Original Message -----
From: "Wilbur" <bwgreen@ocean.otr.usm.edu>
To: <dakota-truck-moderator@bent.twistedbits.net>
Sent: Saturday, January 24, 2004 4:52 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