sparkplug blow by

Hi all,
I have a 1986 Cherokee Pioneer with the dreaded 2.5L I noticed while under
the hood checking vacuum problems that I have a small blow by ...its around
a sparkplug... have tried pulling the plug and cleaning around it and
everything..no dirt or anothing there. Any idea's on how to fix this... With
the blowby I am losing compression in turn losing power... any help would be
great! Thanks in advance!!

Tracy

Is it missing the sealing washer?

If not, I would try another plug. If it still leaks, well.....

If the threads are stripped, you can retap them and put a sleeve in for
an oversize hole, if it has a crack, it is likely a dead head.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Knight wrote:
>
> Hi all,
> I have a 1986 Cherokee Pioneer with the dreaded 2.5L I noticed while under
> the hood checking vacuum problems that I have a small blow by ...its around
> a sparkplug... have tried pulling the plug and cleaning around it and
> everything..no dirt or anothing there. Any idea's on how to fix this... With
> the blowby I am losing compression in turn losing power... any help would be
> great! Thanks in advance!!
>
> Tracy

Yeah it has the washer. I was thinking about retapping and doing the whole
sleeve thing because as far as I can tell there are no cracks. By the way I
did get my signal lights fixed....if you remember. Now I just need to get
the oil problem fixed...I think most of the oil is coming from the rubber
gromets that hold the pvc valve and the valve cover breather in place.
Anyways Thanks again Mike. I've been having all kinds of fun in the snow
this year with the old jeep.

Tracy

"Mike Romain" > wrote in message
...
> Is it missing the sealing washer?
>
> If not, I would try another plug. If it still leaks, well.....
>
> If the threads are stripped, you can retap them and put a sleeve in for
> an oversize hole, if it has a crack, it is likely a dead head.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Knight wrote:
> >
> > Hi all,
> > I have a 1986 Cherokee Pioneer with the dreaded 2.5L I noticed while
under
> > the hood checking vacuum problems that I have a small blow by ...its
around
> > a sparkplug... have tried pulling the plug and cleaning around it and
> > everything..no dirt or anothing there. Any idea's on how to fix this...
With
> > the blowby I am losing compression in turn losing power... any help
would be
> > great! Thanks in advance!!
> >
> > Tracy

look at the threads in the head.
if they are bad, you can rethread them and screw in a helicoil thread
setup. , or change the heads.
old john

"Knight" > wrote in message
...
> Hi all,
> I have a 1986 Cherokee Pioneer with the dreaded 2.5L I noticed while under
> the hood checking vacuum problems that I have a small blow by ...its
around
> a sparkplug... have tried pulling the plug and cleaning around it and
> everything..no dirt or anothing there. Any idea's on how to fix this...
With
> the blowby I am losing compression in turn losing power... any help would
be
> great! Thanks in advance!!
>
> Tracy
>
>

Knight did pass the time by typing:
> Hi all,
> I have a 1986 Cherokee Pioneer with the dreaded 2.5L I noticed while under
> the hood checking vacuum problems that I have a small blow by ...its around
> a sparkplug... have tried pulling the plug and cleaning around it and
> everything..no dirt or anothing there. Any idea's on how to fix this... With
> the blowby I am losing compression in turn losing power... any help would be
> great! Thanks in advance!!

swap plugs and see if the problem moves.
If so it's the plug that's cracked, if not it's
the threads.

That's the number one reason why a torque wrench should be used on sparkplugs.
I've seen several engines where a gorilla twisted the threads off.

Save-a-thread works
http://toolrage.com/prodView.asp?idproduct=1091
http://www.metricscrew-toolco.com/newpg1.html

Remember to use oil on the tap and remove/clean it
frequently. Any metal shavings in the cyl will be bad juju.

--
DougW

> That's the number one reason why a torque wrench should be used on
> sparkplugs.
> I've seen several engines where a gorilla twisted the threads off.

It also controls the stretch on the plug, which changes the gap and heat. I
didn't believe it until I tried plugs set by hand on an emissions machine,
then by torque wrench. It made a measurable difference.

--
Paul Calman, Hathaway Pines, California