I had my 88 MJ 4.0 give me a flicker last summer when I shut it down
on a steep downslope (felt like it was standing on it's nose, couldn't
close the doors if I wanted to) then started it back up a while later
after we moved the log that was in the way (no, there was no way to
climb over it <g>). I figured that the oil had simply drained to the
front of the pan and it gulped air as I rocked it. Shouldn't do that
on a (near) level, tho. Were you low on oil? Did the idle droop
especially low maybe?

On Mon, 7 Jun 2004 17:48:02 UTC "Endo" <me@oh.my> wrote:

> I was out on a trail with my '97 TJ and as I was sitting idling all of a
> sudden mine dropped to almost nothing and the 'check gauges' light came on.
> I rev'd it a couple times and it went back to almost normal and when I
> finally got back to pavement it was pretty much business as usual. It has
> never happened again either. I wonder what happened in my case? Something
> momentarily obstructed the pickup tube or the pump got something stuck in
> it?
>
> Shawn
>
>
> "Will Honea" <hwj25(remove this)@qwest.net> wrote in message
> news:JxX2tWiP5BNp-pn2-t55oZpnWQdhF@anon.none.net...
> > On Mon, 7 Jun 2004 04:00:57 UTC "Cal" <codom1*IHATESPAM*@triad.rr.com>
> > wrote:
> >
> > > I have seen a lot of posts here about oil pressure senders failing on
> 97's,
> > > but I want to just see if this fits the profile..
> > >
> > > My sons wrangler, 4cyl, suddenly started showing about 20 lbs pressure
> at
> > > idle. The pressure swings with engine speed, to about 45-50 lbs at
> highway
> > > speeds (1500 to 2500 rpm) and will drop quickly again at idle to 20-30
> lbs..
> > > Even though the manual states this is ok, it has never changed this much
> > > before. (usually stays over 40lbs even at idle when hot.) This was
> sudden.
> > > No change in the sound of the engine. Changed oil several weeks ago,
> and it
> > > is still up to 'full'. My grand cherokee's sender went out last winter
> > > (also a 97), but it behaved very differently (the pressure would just
> > > randomly drop and rise..) I plan to replace the sender as soon as I can
> get
> > > one, but I ask if anyone has any other ideas...
> >
> > Sounds pretty normal once it is warmed up completely. I'd expect the
> > idle pressure to start off higher then decrese to to 20 psi or so. I
> > did have to swap out an oil pump last summer because the highway
> > pressure dropped 10-15 PSI during the course of a 200 mile trip
> > (verified with a mechanical guage) but the pressure (hot) should
> > pretty much track the RPM with no rapid changes at any particular RPM.
> > Mine does drop a bit lower with really high OAT on a long, sustained
> > run but even I get a tad limp when the air temp pushes 100 F.
> >
> > --
> > Will Honea
>
>


--
Will Honea

 

I had my 88 MJ 4.0 give me a flicker last summer when I shut it down
on a steep downslope (felt like it was standing on it's nose, couldn't
close the doors if I wanted to) then started it back up a while later
after we moved the log that was in the way (no, there was no way to
climb over it <g>). I figured that the oil had simply drained to the
front of the pan and it gulped air as I rocked it. Shouldn't do that
on a (near) level, tho. Were you low on oil? Did the idle droop
especially low maybe?

On Mon, 7 Jun 2004 17:48:02 UTC "Endo" <me@oh.my> wrote:

> I was out on a trail with my '97 TJ and as I was sitting idling all of a
> sudden mine dropped to almost nothing and the 'check gauges' light came on.
> I rev'd it a couple times and it went back to almost normal and when I
> finally got back to pavement it was pretty much business as usual. It has
> never happened again either. I wonder what happened in my case? Something
> momentarily obstructed the pickup tube or the pump got something stuck in
> it?
>
> Shawn
>
>
> "Will Honea" <hwj25(remove this)@qwest.net> wrote in message
> news:JxX2tWiP5BNp-pn2-t55oZpnWQdhF@anon.none.net...
> > On Mon, 7 Jun 2004 04:00:57 UTC "Cal" <codom1*IHATESPAM*@triad.rr.com>
> > wrote:
> >
> > > I have seen a lot of posts here about oil pressure senders failing on
> 97's,
> > > but I want to just see if this fits the profile..
> > >
> > > My sons wrangler, 4cyl, suddenly started showing about 20 lbs pressure
> at
> > > idle. The pressure swings with engine speed, to about 45-50 lbs at
> highway
> > > speeds (1500 to 2500 rpm) and will drop quickly again at idle to 20-30
> lbs..
> > > Even though the manual states this is ok, it has never changed this much
> > > before. (usually stays over 40lbs even at idle when hot.) This was
> sudden.
> > > No change in the sound of the engine. Changed oil several weeks ago,
> and it
> > > is still up to 'full'. My grand cherokee's sender went out last winter
> > > (also a 97), but it behaved very differently (the pressure would just
> > > randomly drop and rise..) I plan to replace the sender as soon as I can
> get
> > > one, but I ask if anyone has any other ideas...
> >
> > Sounds pretty normal once it is warmed up completely. I'd expect the
> > idle pressure to start off higher then decrese to to 20 psi or so. I
> > did have to swap out an oil pump last summer because the highway
> > pressure dropped 10-15 PSI during the course of a 200 mile trip
> > (verified with a mechanical guage) but the pressure (hot) should
> > pretty much track the RPM with no rapid changes at any particular RPM.
> > Mine does drop a bit lower with really high OAT on a long, sustained
> > run but even I get a tad limp when the air temp pushes 100 F.
> >
> > --
> > Will Honea
>
>


--
Will Honea

 

I had my 88 MJ 4.0 give me a flicker last summer when I shut it down
on a steep downslope (felt like it was standing on it's nose, couldn't
close the doors if I wanted to) then started it back up a while later
after we moved the log that was in the way (no, there was no way to
climb over it <g>). I figured that the oil had simply drained to the
front of the pan and it gulped air as I rocked it. Shouldn't do that
on a (near) level, tho. Were you low on oil? Did the idle droop
especially low maybe?

On Mon, 7 Jun 2004 17:48:02 UTC "Endo" <me@oh.my> wrote:

> I was out on a trail with my '97 TJ and as I was sitting idling all of a
> sudden mine dropped to almost nothing and the 'check gauges' light came on.
> I rev'd it a couple times and it went back to almost normal and when I
> finally got back to pavement it was pretty much business as usual. It has
> never happened again either. I wonder what happened in my case? Something
> momentarily obstructed the pickup tube or the pump got something stuck in
> it?
>
> Shawn
>
>
> "Will Honea" <hwj25(remove this)@qwest.net> wrote in message
> news:JxX2tWiP5BNp-pn2-t55oZpnWQdhF@anon.none.net...
> > On Mon, 7 Jun 2004 04:00:57 UTC "Cal" <codom1*IHATESPAM*@triad.rr.com>
> > wrote:
> >
> > > I have seen a lot of posts here about oil pressure senders failing on
> 97's,
> > > but I want to just see if this fits the profile..
> > >
> > > My sons wrangler, 4cyl, suddenly started showing about 20 lbs pressure
> at
> > > idle. The pressure swings with engine speed, to about 45-50 lbs at
> highway
> > > speeds (1500 to 2500 rpm) and will drop quickly again at idle to 20-30
> lbs..
> > > Even though the manual states this is ok, it has never changed this much
> > > before. (usually stays over 40lbs even at idle when hot.) This was
> sudden.
> > > No change in the sound of the engine. Changed oil several weeks ago,
> and it
> > > is still up to 'full'. My grand cherokee's sender went out last winter
> > > (also a 97), but it behaved very differently (the pressure would just
> > > randomly drop and rise..) I plan to replace the sender as soon as I can
> get
> > > one, but I ask if anyone has any other ideas...
> >
> > Sounds pretty normal once it is warmed up completely. I'd expect the
> > idle pressure to start off higher then decrese to to 20 psi or so. I
> > did have to swap out an oil pump last summer because the highway
> > pressure dropped 10-15 PSI during the course of a 200 mile trip
> > (verified with a mechanical guage) but the pressure (hot) should
> > pretty much track the RPM with no rapid changes at any particular RPM.
> > Mine does drop a bit lower with really high OAT on a long, sustained
> > run but even I get a tad limp when the air temp pushes 100 F.
> >
> > --
> > Will Honea
>
>


--
Will Honea

 

It was at crawling at idle on mostly level ground from what I remember.
Can't think of anything external that could have caused it. Wonder if it
was a symptom of faulty contacts on the back of my instrument cluster? I've
had the turn signal indicators go out a few times. It did light the 'check
gauges' light though. Not sure if that is computer controlled or built in
to the cluster.

Shawn


"Will Honea" <hwj25(remove this)@qwest.net> wrote in message
news:JxX2tWiP5BNp-pn2-vBjnSdhw3H3O@anon.none.net...
> I had my 88 MJ 4.0 give me a flicker last summer when I shut it down
> on a steep downslope (felt like it was standing on it's nose, couldn't
> close the doors if I wanted to) then started it back up a while later
> after we moved the log that was in the way (no, there was no way to
> climb over it <g>). I figured that the oil had simply drained to the
> front of the pan and it gulped air as I rocked it. Shouldn't do that
> on a (near) level, tho. Were you low on oil? Did the idle droop
> especially low maybe?
>
> On Mon, 7 Jun 2004 17:48:02 UTC "Endo" <me@oh.my> wrote:
>
> > I was out on a trail with my '97 TJ and as I was sitting idling all of a
> > sudden mine dropped to almost nothing and the 'check gauges' light came
on.
> > I rev'd it a couple times and it went back to almost normal and when I
> > finally got back to pavement it was pretty much business as usual. It
has
> > never happened again either. I wonder what happened in my case?
Something
> > momentarily obstructed the pickup tube or the pump got something stuck
in
> > it?
> >
> > Shawn
> >
> >
> > "Will Honea" <hwj25(remove this)@qwest.net> wrote in message
> > news:JxX2tWiP5BNp-pn2-t55oZpnWQdhF@anon.none.net...
> > > On Mon, 7 Jun 2004 04:00:57 UTC "Cal" <codom1*IHATESPAM*@triad.rr.com>
> > > wrote:
> > >
> > > > I have seen a lot of posts here about oil pressure senders failing
on
> > 97's,
> > > > but I want to just see if this fits the profile..
> > > >
> > > > My sons wrangler, 4cyl, suddenly started showing about 20 lbs
pressure
> > at
> > > > idle. The pressure swings with engine speed, to about 45-50 lbs at
> > highway
> > > > speeds (1500 to 2500 rpm) and will drop quickly again at idle to
20-30
> > lbs..
> > > > Even though the manual states this is ok, it has never changed this
much
> > > > before. (usually stays over 40lbs even at idle when hot.) This was
> > sudden.
> > > > No change in the sound of the engine. Changed oil several weeks
ago,
> > and it
> > > > is still up to 'full'. My grand cherokee's sender went out last
winter
> > > > (also a 97), but it behaved very differently (the pressure would
just
> > > > randomly drop and rise..) I plan to replace the sender as soon as I
can
> > get
> > > > one, but I ask if anyone has any other ideas...
> > >
> > > Sounds pretty normal once it is warmed up completely. I'd expect the
> > > idle pressure to start off higher then decrese to to 20 psi or so. I
> > > did have to swap out an oil pump last summer because the highway
> > > pressure dropped 10-15 PSI during the course of a 200 mile trip
> > > (verified with a mechanical guage) but the pressure (hot) should
> > > pretty much track the RPM with no rapid changes at any particular RPM.
> > > Mine does drop a bit lower with really high OAT on a long, sustained
> > > run but even I get a tad limp when the air temp pushes 100 F.
> > >
> > > --
> > > Will Honea
> >
> >
>
>
> --
> Will Honea

 

It was at crawling at idle on mostly level ground from what I remember.
Can't think of anything external that could have caused it. Wonder if it
was a symptom of faulty contacts on the back of my instrument cluster? I've
had the turn signal indicators go out a few times. It did light the 'check
gauges' light though. Not sure if that is computer controlled or built in
to the cluster.

Shawn


"Will Honea" <hwj25(remove this)@qwest.net> wrote in message
news:JxX2tWiP5BNp-pn2-vBjnSdhw3H3O@anon.none.net...
> I had my 88 MJ 4.0 give me a flicker last summer when I shut it down
> on a steep downslope (felt like it was standing on it's nose, couldn't
> close the doors if I wanted to) then started it back up a while later
> after we moved the log that was in the way (no, there was no way to
> climb over it <g>). I figured that the oil had simply drained to the
> front of the pan and it gulped air as I rocked it. Shouldn't do that
> on a (near) level, tho. Were you low on oil? Did the idle droop
> especially low maybe?
>
> On Mon, 7 Jun 2004 17:48:02 UTC "Endo" <me@oh.my> wrote:
>
> > I was out on a trail with my '97 TJ and as I was sitting idling all of a
> > sudden mine dropped to almost nothing and the 'check gauges' light came
on.
> > I rev'd it a couple times and it went back to almost normal and when I
> > finally got back to pavement it was pretty much business as usual. It
has
> > never happened again either. I wonder what happened in my case?
Something
> > momentarily obstructed the pickup tube or the pump got something stuck
in
> > it?
> >
> > Shawn
> >
> >
> > "Will Honea" <hwj25(remove this)@qwest.net> wrote in message
> > news:JxX2tWiP5BNp-pn2-t55oZpnWQdhF@anon.none.net...
> > > On Mon, 7 Jun 2004 04:00:57 UTC "Cal" <codom1*IHATESPAM*@triad.rr.com>
> > > wrote:
> > >
> > > > I have seen a lot of posts here about oil pressure senders failing
on
> > 97's,
> > > > but I want to just see if this fits the profile..
> > > >
> > > > My sons wrangler, 4cyl, suddenly started showing about 20 lbs
pressure
> > at
> > > > idle. The pressure swings with engine speed, to about 45-50 lbs at
> > highway
> > > > speeds (1500 to 2500 rpm) and will drop quickly again at idle to
20-30
> > lbs..
> > > > Even though the manual states this is ok, it has never changed this
much
> > > > before. (usually stays over 40lbs even at idle when hot.) This was
> > sudden.
> > > > No change in the sound of the engine. Changed oil several weeks
ago,
> > and it
> > > > is still up to 'full'. My grand cherokee's sender went out last
winter
> > > > (also a 97), but it behaved very differently (the pressure would
just
> > > > randomly drop and rise..) I plan to replace the sender as soon as I
can
> > get
> > > > one, but I ask if anyone has any other ideas...
> > >
> > > Sounds pretty normal once it is warmed up completely. I'd expect the
> > > idle pressure to start off higher then decrese to to 20 psi or so. I
> > > did have to swap out an oil pump last summer because the highway
> > > pressure dropped 10-15 PSI during the course of a 200 mile trip
> > > (verified with a mechanical guage) but the pressure (hot) should
> > > pretty much track the RPM with no rapid changes at any particular RPM.
> > > Mine does drop a bit lower with really high OAT on a long, sustained
> > > run but even I get a tad limp when the air temp pushes 100 F.
> > >
> > > --
> > > Will Honea
> >
> >
>
>
> --
> Will Honea

 

It was at crawling at idle on mostly level ground from what I remember.
Can't think of anything external that could have caused it. Wonder if it
was a symptom of faulty contacts on the back of my instrument cluster? I've
had the turn signal indicators go out a few times. It did light the 'check
gauges' light though. Not sure if that is computer controlled or built in
to the cluster.

Shawn


"Will Honea" <hwj25(remove this)@qwest.net> wrote in message
news:JxX2tWiP5BNp-pn2-vBjnSdhw3H3O@anon.none.net...
> I had my 88 MJ 4.0 give me a flicker last summer when I shut it down
> on a steep downslope (felt like it was standing on it's nose, couldn't
> close the doors if I wanted to) then started it back up a while later
> after we moved the log that was in the way (no, there was no way to
> climb over it <g>). I figured that the oil had simply drained to the
> front of the pan and it gulped air as I rocked it. Shouldn't do that
> on a (near) level, tho. Were you low on oil? Did the idle droop
> especially low maybe?
>
> On Mon, 7 Jun 2004 17:48:02 UTC "Endo" <me@oh.my> wrote:
>
> > I was out on a trail with my '97 TJ and as I was sitting idling all of a
> > sudden mine dropped to almost nothing and the 'check gauges' light came
on.
> > I rev'd it a couple times and it went back to almost normal and when I
> > finally got back to pavement it was pretty much business as usual. It
has
> > never happened again either. I wonder what happened in my case?
Something
> > momentarily obstructed the pickup tube or the pump got something stuck
in
> > it?
> >
> > Shawn
> >
> >
> > "Will Honea" <hwj25(remove this)@qwest.net> wrote in message
> > news:JxX2tWiP5BNp-pn2-t55oZpnWQdhF@anon.none.net...
> > > On Mon, 7 Jun 2004 04:00:57 UTC "Cal" <codom1*IHATESPAM*@triad.rr.com>
> > > wrote:
> > >
> > > > I have seen a lot of posts here about oil pressure senders failing
on
> > 97's,
> > > > but I want to just see if this fits the profile..
> > > >
> > > > My sons wrangler, 4cyl, suddenly started showing about 20 lbs
pressure
> > at
> > > > idle. The pressure swings with engine speed, to about 45-50 lbs at
> > highway
> > > > speeds (1500 to 2500 rpm) and will drop quickly again at idle to
20-30
> > lbs..
> > > > Even though the manual states this is ok, it has never changed this
much
> > > > before. (usually stays over 40lbs even at idle when hot.) This was
> > sudden.
> > > > No change in the sound of the engine. Changed oil several weeks
ago,
> > and it
> > > > is still up to 'full'. My grand cherokee's sender went out last
winter
> > > > (also a 97), but it behaved very differently (the pressure would
just
> > > > randomly drop and rise..) I plan to replace the sender as soon as I
can
> > get
> > > > one, but I ask if anyone has any other ideas...
> > >
> > > Sounds pretty normal once it is warmed up completely. I'd expect the
> > > idle pressure to start off higher then decrese to to 20 psi or so. I
> > > did have to swap out an oil pump last summer because the highway
> > > pressure dropped 10-15 PSI during the course of a 200 mile trip
> > > (verified with a mechanical guage) but the pressure (hot) should
> > > pretty much track the RPM with no rapid changes at any particular RPM.
> > > Mine does drop a bit lower with really high OAT on a long, sustained
> > > run but even I get a tad limp when the air temp pushes 100 F.
> > >
> > > --
> > > Will Honea
> >
> >
>
>
> --
> Will Honea

 

It was at crawling at idle on mostly level ground from what I remember.
Can't think of anything external that could have caused it. Wonder if it
was a symptom of faulty contacts on the back of my instrument cluster? I've
had the turn signal indicators go out a few times. It did light the 'check
gauges' light though. Not sure if that is computer controlled or built in
to the cluster.

Shawn


"Will Honea" <hwj25(remove this)@qwest.net> wrote in message
news:JxX2tWiP5BNp-pn2-vBjnSdhw3H3O@anon.none.net...
> I had my 88 MJ 4.0 give me a flicker last summer when I shut it down
> on a steep downslope (felt like it was standing on it's nose, couldn't
> close the doors if I wanted to) then started it back up a while later
> after we moved the log that was in the way (no, there was no way to
> climb over it <g>). I figured that the oil had simply drained to the
> front of the pan and it gulped air as I rocked it. Shouldn't do that
> on a (near) level, tho. Were you low on oil? Did the idle droop
> especially low maybe?
>
> On Mon, 7 Jun 2004 17:48:02 UTC "Endo" <me@oh.my> wrote:
>
> > I was out on a trail with my '97 TJ and as I was sitting idling all of a
> > sudden mine dropped to almost nothing and the 'check gauges' light came
on.
> > I rev'd it a couple times and it went back to almost normal and when I
> > finally got back to pavement it was pretty much business as usual. It
has
> > never happened again either. I wonder what happened in my case?
Something
> > momentarily obstructed the pickup tube or the pump got something stuck
in
> > it?
> >
> > Shawn
> >
> >
> > "Will Honea" <hwj25(remove this)@qwest.net> wrote in message
> > news:JxX2tWiP5BNp-pn2-t55oZpnWQdhF@anon.none.net...
> > > On Mon, 7 Jun 2004 04:00:57 UTC "Cal" <codom1*IHATESPAM*@triad.rr.com>
> > > wrote:
> > >
> > > > I have seen a lot of posts here about oil pressure senders failing
on
> > 97's,
> > > > but I want to just see if this fits the profile..
> > > >
> > > > My sons wrangler, 4cyl, suddenly started showing about 20 lbs
pressure
> > at
> > > > idle. The pressure swings with engine speed, to about 45-50 lbs at
> > highway
> > > > speeds (1500 to 2500 rpm) and will drop quickly again at idle to
20-30
> > lbs..
> > > > Even though the manual states this is ok, it has never changed this
much
> > > > before. (usually stays over 40lbs even at idle when hot.) This was
> > sudden.
> > > > No change in the sound of the engine. Changed oil several weeks
ago,
> > and it
> > > > is still up to 'full'. My grand cherokee's sender went out last
winter
> > > > (also a 97), but it behaved very differently (the pressure would
just
> > > > randomly drop and rise..) I plan to replace the sender as soon as I
can
> > get
> > > > one, but I ask if anyone has any other ideas...
> > >
> > > Sounds pretty normal once it is warmed up completely. I'd expect the
> > > idle pressure to start off higher then decrese to to 20 psi or so. I
> > > did have to swap out an oil pump last summer because the highway
> > > pressure dropped 10-15 PSI during the course of a 200 mile trip
> > > (verified with a mechanical guage) but the pressure (hot) should
> > > pretty much track the RPM with no rapid changes at any particular RPM.
> > > Mine does drop a bit lower with really high OAT on a long, sustained
> > > run but even I get a tad limp when the air temp pushes 100 F.
> > >
> > > --
> > > Will Honea
> >
> >
>
>
> --
> Will Honea

 

>I was out on a trail with my '97 TJ and as I was sitting idling all of a
>sudden mine dropped to almost nothing and the 'check gauges' light came
>on.
>I rev'd it a couple times and it went back to almost normal and when I
>finally got back to pavement it was pretty much business as usual. It has
>never happened again either. I wonder what happened in my case?

That's EXACTLY what my '97 4.0L was doing; it was the OP sender!

-jeff

 

>I was out on a trail with my '97 TJ and as I was sitting idling all of a
>sudden mine dropped to almost nothing and the 'check gauges' light came
>on.
>I rev'd it a couple times and it went back to almost normal and when I
>finally got back to pavement it was pretty much business as usual. It has
>never happened again either. I wonder what happened in my case?

That's EXACTLY what my '97 4.0L was doing; it was the OP sender!

-jeff

 

>I was out on a trail with my '97 TJ and as I was sitting idling all of a
>sudden mine dropped to almost nothing and the 'check gauges' light came
>on.
>I rev'd it a couple times and it went back to almost normal and when I
>finally got back to pavement it was pretty much business as usual. It has
>never happened again either. I wonder what happened in my case?

That's EXACTLY what my '97 4.0L was doing; it was the OP sender!

-jeff