Oil Pressure Hits Zero And Stays There- JGC '96

Most of us do fine with a GOOD hydraulic floor jack, some jackstands,
and a piece of cardboard to lay on. OK, I've got a floor creeper and
find the cardboard is just as good.



NJPainter wrote:

> thanks for the advice and the inspiration...
>
> I'm a little scared about going to the dealership. I won't be able to
> negotiate price, so I hope I get a cool mechanic to work with. I hope
> it's something small, but I'll probably back on here tomorrow crying
> about how much I just spent.
>
> How do you do your own work without a lift?
>

Dealer said it wasn't going to be the CPU so I picked their brain and
walked out before letting them diagnose the car at $94 and hour plus
tax.

Guy behind the desk suggested wear, and quoted engine replacement
around $7K. Whatever...
Mechanic said it may be wiring but that could take hours to sort out.
Going to have the mechanic take off the valve cover and see if theirs
blockage.

Considering all the possibilities, sludge or deposits seem to be the
culprit. To recap, the engine's been flushed(basic method), sensor and
oil pump were replaced. I should note that the oil pump was dinged up,
the metal plate was scored and the moving parts had some dings and
whatnot.

Is this just a simple case of engine wear? If it is, should I use
two quarts Lucas per oil change instead of one, or just switch to a
20-50? Everyone I spoke to says that engine replacement would be the
smartest option, versus having someone open it up and work on specific
parts. The engine has 164K on it. The previous owner did regular oil
changes w/ synthetic, and I've followed suit...

Herb Leong wrote:

>
> #It is also 'super' easy to clear the CPU codes... Just disconnect the
> #battery for a few minutes.... There are also auto store places that
> #will check the codes for free.
> Checking them should just be a matter of turn the ignition on, off, on,
> off, on without cranking...
>
> /herb

thx-

My mechanic sent me to the dealer to have the CPU flashed? He said
that only the dealers can reprogram the cars. The dealer told me that
the CPU has nothing to do with it. They said it could be wiring, wear
or possibly blockage.

I was leery of having the dealership do work, or even the diagnostic
this morning because the cost seemed out of hand. I'm leaning towards
having my mechanic clean out the returns since I read in another thread
that that worked for another guy with the same problem...

thx

my mechanic said he'd run it for me, but he said the engine would've
f-d up already if there wasn't any pressure.

You are driving me insane reading this!

Why oh why don't you just get a mechanical oil pressure gauge and put it
in there instead of letting those so called 'mechanics' rip you off
blind?

None of the bull**** 'fixes' you have posted here has been valid.

Arrgggg!

Or are you one of those 'fools and their money'?

On that note, I am off bush running in my Jeep for the weekend, good
luck.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

NJPainter wrote:
>
> Dealer said it wasn't going to be the CPU so I picked their brain and
> walked out before letting them diagnose the car at $94 and hour plus
> tax.
>
> Guy behind the desk suggested wear, and quoted engine replacement
> around $7K. Whatever...
> Mechanic said it may be wiring but that could take hours to sort out.
> Going to have the mechanic take off the valve cover and see if theirs
> blockage.
>
> Considering all the possibilities, sludge or deposits seem to be the
> culprit. To recap, the engine's been flushed(basic method), sensor and
> oil pump were replaced. I should note that the oil pump was dinged up,
> the metal plate was scored and the moving parts had some dings and
> whatnot.
>
> Is this just a simple case of engine wear? If it is, should I use
> two quarts Lucas per oil change instead of one, or just switch to a
> 20-50? Everyone I spoke to says that engine replacement would be the
> smartest option, versus having someone open it up and work on specific
> parts. The engine has 164K on it. The previous owner did regular oil
> changes w/ synthetic, and I've followed suit...

Jeffrey DeWitt wrote:
> 4000 miles isn't really that long, and it's not NEARLY enough to cause
> the kind of problem you are having. If you regularly drove it 10,000
> miles or more between oil changes then you could have this problem, but
> not one 4,000 interval.
>

what if I used Hyperlube, instead of Lucas?

Man, I don't know what the deal is, all I know is that I let the oil
go to long in the dead of the summer, when I was doing a ton of stop
and go driving, stops, and re-starts. About 4 or 5 a day.

The problem first presented itself after driving 40 minutes or so at
70-80 MPH, then sitting in traffic for another half hour or more.
That's why I think it has to do with the oil. But I'm probably wrong.

Correct, so therefore there is 'Nothing' wrong with your engine!

'If' the new sender works, then you have a defect in the wire to the
dash or a defect in the dash circuit board. A cold solder joint in a
circuit board acts just like you describe. The ground for the sender is
bolted to the dipstick, look for some small black wires there, maybe one
is bad.

For less than 50 bucks you can install a mechanical oil pressure gauge
under your dash and forget about the stock one.

For that matter, you don't 'need' a gauge at all. The engine will rattle
really good if it actually does lose oil pressure.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

NJPainter wrote:
>
> my mechanic said he'd run it for me, but he said the engine would've
> f-d up already if there wasn't any pressure.

Today it took 15 minutes to bottom out. I'm thinking if I put a higher
weight oil in there it might do the trick. I'm also switching out the
FRAM filter. I read of another guy who changed out the Fram and the
problem went away. I noticed that the Fram Tough Guard has smaller
holes than the Pure One.

Is your engine still running?

If yes, then the gauge is just plain lying to you!

If no, then you really do need engine work or oil work.

There is 'no' in-between.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

NJPainter wrote:
>
> Today it took 15 minutes to bottom out. I'm thinking if I put a higher
> weight oil in there it might do the trick. I'm also switching out the
> FRAM filter. I read of another guy who changed out the Fram and the
> problem went away. I noticed that the Fram Tough Guard has smaller
> holes than the Pure One.

Mike Romain wrote:
> Is your engine still running?
>
> If yes, then the gauge is just plain lying to you!
>
> If no, then you really do need engine work or oil work.
>
> There is 'no' in-between.
>
>

Engine is running, but doesn't seem to run as strong when the pressure
is at zero. What weight oil would you recommend?