Mike Romain did pass the time by typing:
> A noisy valve normally won't hurt anything. If it gets worse, it needs
> attention.

An exhaust leak back at #6 will also sound quite a bit like a lifter
ticking. Best method for determining the noise source is a mechanics
stethoscope.

> Peter Pontbriand wrote:
>>
>> Ok, thanks. It's not a 'when cold' thing though - if anything it happens
>> more when the engine is warm than when it is cold. The sound seems to occur
>> about four or five times per second when idling at 500 RPM, which makes it 1
>> sound per 2 rotations of the crank. So, more likely a valvetrain thing than
>> piston slap, right?
>>
>> Can much harm come from ignoring it?

 

Mike Romain did pass the time by typing:
> A noisy valve normally won't hurt anything. If it gets worse, it needs
> attention.

An exhaust leak back at #6 will also sound quite a bit like a lifter
ticking. Best method for determining the noise source is a mechanics
stethoscope.

> Peter Pontbriand wrote:
>>
>> Ok, thanks. It's not a 'when cold' thing though - if anything it happens
>> more when the engine is warm than when it is cold. The sound seems to occur
>> about four or five times per second when idling at 500 RPM, which makes it 1
>> sound per 2 rotations of the crank. So, more likely a valvetrain thing than
>> piston slap, right?
>>
>> Can much harm come from ignoring it?

 

That's typical of lifter noise. BAD on cold start_up ... goes away when oil
pressure surges ..... then re_establishes when oil temp comes up and
viscosity goes down.


"Peter Pontbriand" <sprocket.who.hates.spam@storm.ca> wrote in message
news:cm8ebc$md$1@news.storm.ca...
> Ok, thanks. It's not a 'when cold' thing though - if anything it happens
> more when the engine is warm than when it is cold. The sound seems to
occur
> about four or five times per second when idling at 500 RPM, which makes it
1
> sound per 2 rotations of the crank. So, more likely a valvetrain thing
than
> piston slap, right?
>
> Can much harm come from ignoring it?
>
> /Peter
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4187B7D9.91ACFB04@sympatico.ca...
> > It makes a tapping/clicking noise. A valve only opens once every second
> > engine stroke so a valve tap is slower than say piston slap which
> > happens every stroke. If you put a timing light on, the valve will tap
> > every second flash.
> >
> > Some of those 4.0 engines do suffer from the occasional piston slap when
> > cold. This won't hurt anything and cannot be repaired without a total
> > engine job.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > Peter Pontbriand wrote:
> > >
> > > What kind of noise does a "noisy lifter" make? I'm curious because my
> '02 TJ
> > > 4.0 has an intermittent "thunking" sound (with accompanying vibration)
> at
> > > idle. I've no idea what that could be, and because it doesn't
> consistently
> > > do it I haven't been able to take it to a shop.
> > >
> > > /Peter
> > >
> > > "Miguel Londono" <miguellondono@usa.net> wrote in message
> > > news:41872bc1$1_1@news.cybersurf.net...
> > > > I also have a 93 yj with the 4.0 with a noisy lifter, my question
is:
> will
> > > > the lifters come out without removing the cylinder head? My factory
> manual
> > > > claims it can be done both ways, true??
> > > >
> > > >
> > > >
> > > > "Joe and Joann" <mauijoe@maui.net> wrote in message
> > > > news:vBghd.33663$Kl3.418@twister.socal.rr.com...
> > > > >I am getting ready to change a noisy lifter in my '90 YJ 4.2L.
Three
> > > > >questions:
> > > > > 1) The Haynes manual says to use Perfect Seal sealing compound on
> the
> > > > > head gasket for the 4.2 L. I have an OEM replacement head gasket.
I
> > > > > thought I had read in this newsgroup that no sealer should be used
> with
> > > > > the head gasket. Any thoughts on this?
> > > > > 2) From what I have been able to find, early 4.2s used a gasket
that
> > > > > covers both the intake and exhaust manifolds and later engines
were
> > > > > equipped with an intake manifold gasket only. Since I haven't
gotten
> > > > > things apart yet, I don't know what kind I have. If you use the
full
> > > > > length gasket that covers the intake and exhaust manifolds, do you
> still
> > > > > need gasket that is for the intake manifold only. Even if the
> existing
> > > > > gasket was the one for the intake only, would I be better off
going
> to
> > > the
> > > > > gasket that covers both?
> > > > > 3) I have the aluminum valve cover. Whats the best sealant to use
on
> the
> > > > > cork gasket? Is it best to put the sealer on both sides? Thin
coat
> or
> > > > > thick?
> > > > >
> > > > > Thanks
> > > > > Joe in Maui HI
> > > >
> > > >
>
>

 

That's typical of lifter noise. BAD on cold start_up ... goes away when oil
pressure surges ..... then re_establishes when oil temp comes up and
viscosity goes down.


"Peter Pontbriand" <sprocket.who.hates.spam@storm.ca> wrote in message
news:cm8ebc$md$1@news.storm.ca...
> Ok, thanks. It's not a 'when cold' thing though - if anything it happens
> more when the engine is warm than when it is cold. The sound seems to
occur
> about four or five times per second when idling at 500 RPM, which makes it
1
> sound per 2 rotations of the crank. So, more likely a valvetrain thing
than
> piston slap, right?
>
> Can much harm come from ignoring it?
>
> /Peter
>
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:4187B7D9.91ACFB04@sympatico.ca...
> > It makes a tapping/clicking noise. A valve only opens once every second
> > engine stroke so a valve tap is slower than say piston slap which
> > happens every stroke. If you put a timing light on, the valve will tap
> > every second flash.
> >
> > Some of those 4.0 engines do suffer from the occasional piston slap when
> > cold. This won't hurt anything and cannot be repaired without a total
> > engine job.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > Peter Pontbriand wrote:
> > >
> > > What kind of noise does a "noisy lifter" make? I'm curious because my
> '02 TJ
> > > 4.0 has an intermittent "thunking" sound (with accompanying vibration)
> at
> > > idle. I've no idea what that could be, and because it doesn't
> consistently
> > > do it I haven't been able to take it to a shop.
> > >
> > > /Peter
> > >
> > > "Miguel Londono" <miguellondono@usa.net> wrote in message
> > > news:41872bc1$1_1@news.cybersurf.net...
> > > > I also have a 93 yj with the 4.0 with a noisy lifter, my question
is:
> will
> > > > the lifters come out without removing the cylinder head? My factory
> manual
> > > > claims it can be done both ways, true??
> > > >
> > > >
> > > >
> > > > "Joe and Joann" <mauijoe@maui.net> wrote in message
> > > > news:vBghd.33663$Kl3.418@twister.socal.rr.com...
> > > > >I am getting ready to change a noisy lifter in my '90 YJ 4.2L.
Three
> > > > >questions:
> > > > > 1) The Haynes manual says to use Perfect Seal sealing compound on
> the
> > > > > head gasket for the 4.2 L. I have an OEM replacement head gasket.
I
> > > > > thought I had read in this newsgroup that no sealer should be used
> with
> > > > > the head gasket. Any thoughts on this?
> > > > > 2) From what I have been able to find, early 4.2s used a gasket
that
> > > > > covers both the intake and exhaust manifolds and later engines
were
> > > > > equipped with an intake manifold gasket only. Since I haven't
gotten
> > > > > things apart yet, I don't know what kind I have. If you use the
full
> > > > > length gasket that covers the intake and exhaust manifolds, do you
> still
> > > > > need gasket that is for the intake manifold only. Even if the
> existing
> > > > > gasket was the one for the intake only, would I be better off
going
> to
> > > the
> > > > > gasket that covers both?
> > > > > 3) I have the aluminum valve cover. Whats the best sealant to use
on
> the
> > > > > cork gasket? Is it best to put the sealer on both sides? Thin
coat
> or
> > > > > thick?
> > > > >
> > > > > Thanks
> > > > > Joe in Maui HI
> > > >
> > > >
>
>