Oil Pressure too high ??

This is a 2000 Jeep Grand Cherokee, V-8, 150,000 miles.

Up until this week, the oil pressure would go up to about 50 lbs when cold,
then would settle down to around 40 lbs, and about 35 lbs at idle.

All of a sudden, the oil pressure gauge shows 70 lbs of pressure at full
speed, and down to about 50 lbs at idle. But at driving speeds, it stays
up at 70 lbs, even after it is warm.

Thus, I have an increase of 20-30 lbs of overall oil pressure.

I have checked my oil level, and it is normal.

What caused this? Is it bad to have too high oil pressure? Can the
sending unit be bad ? I had thought not, as these readings are stable, and
not erratic.

Any ideas or advice ? (don't laugh.... I guess the advice will be to be
glad to have good oil pressure on an engine with 150k miles... ha ha)

Thanks !!

James

Hi James,
I would start by cleaning the connection at the oil pressure switch. If
it's on the oil pump side of the filter like the six, a clog filter could do
it. So go ahead change them. And, of course many times it's the switch that
fails, maybe leaking oil on the other side of it's diaphragm. That's why
Real Jeeps have aftermarket oil and temperature gauges by a major
manufacture, like Stewart Warner, or Auto Meter.
God Bless America, Bill O|||||||O
http://www.billhughes.com/


"James" > wrote in message
. ..
> This is a 2000 Jeep Grand Cherokee, V-8, 150,000 miles.
>
> Up until this week, the oil pressure would go up to about 50 lbs when
cold,
> then would settle down to around 40 lbs, and about 35 lbs at idle.
>
> All of a sudden, the oil pressure gauge shows 70 lbs of pressure at full
> speed, and down to about 50 lbs at idle. But at driving speeds, it stays
> up at 70 lbs, even after it is warm.
>
> Thus, I have an increase of 20-30 lbs of overall oil pressure.
>
> I have checked my oil level, and it is normal.
>
> What caused this? Is it bad to have too high oil pressure? Can the
> sending unit be bad ? I had thought not, as these readings are stable,
and
> not erratic.
>
> Any ideas or advice ? (don't laugh.... I guess the advice will be to
be
> glad to have good oil pressure on an engine with 150k miles... ha ha)
>
> Thanks !!
>
> James
>
>

James wrote:
> This is a 2000 Jeep Grand Cherokee, V-8, 150,000 miles.
>
> Up until this week, the oil pressure would go up to about 50 lbs when
> cold, then would settle down to around 40 lbs, and about 35 lbs at
> idle.
>
> All of a sudden, the oil pressure gauge shows 70 lbs of pressure at
> full speed, and down to about 50 lbs at idle. But at driving
> speeds, it stays up at 70 lbs, even after it is warm.
>
> Thus, I have an increase of 20-30 lbs of overall oil pressure.
>
> I have checked my oil level, and it is normal.
>
> What caused this? Is it bad to have too high oil pressure? Can the
> sending unit be bad ? I had thought not, as these readings are
> stable, and not erratic.

Bad sending unit.

If it was just pegged at 70 I'd say the wire to the sensor was loose,
but creeping high pressure is a sign of a sender going bad.


--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

Thanks Bill !!

James

James wrote:
> Thanks Bill !!
>
> James
>
>
With the caution that I do not know how much it costs on your particular
Grand, the failure on the pressure sensor is usually internal, where
replacing it is reasonably cheap and quite simple. The sensors on the
Grands are notoriously flaky and unreliable.

As most of you advised, it was the oil pressure sending unit that was
defective. With the installation of a new one, the oil pressure readings
are in the normal range for this car/ 40/60 lbs from idle to full speed.

thanks for the help !!

James

James wrote:
> As most of you advised, it was the oil pressure sending unit that was
> defective. With the installation of a new one, the oil pressure
> readings are in the normal range for this car/ 40/60 lbs from idle
> to full speed.
>
> thanks for the help !!

Glad to know that was the problem.

Seems in about 99% of the cases (the other
1% being where the engine goes paff) it's
the pressure sender.

--
DougW