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 - 16:29:50 EST