Grand Cherokee Oil Pressure
 

Man, I'm having a go with my Jeeps this month.

We also own a 94 Grand Cherokee 318 V8 and have often noticed the dip
stick accuracy seems to be sensitive to shut-down time and vehicle
angle.

Last week it showed 1 Qt low so I added one. A couple of days ago I
checked the oil level and it is showed ONE OVER and the oil pressure
gauge shoots right over to max pressure after startup and doesn't
waver from max until the engine shuts down. We don't know when the
gauge began reading max only...

I've drained one liter- clean oil- no water... Changed the filter -
the old one came out EMPTY... Still the gauge shoots and stays at
max.

There are no rattles and the engine runs as always before- perfectly.

What do you think: sender unit or something serious like a partially
spun bearing?

Re: Grand Cherokee Oil Pressure
 

jim.c.christiansen wrote:
> Man, I'm having a go with my Jeeps this month.
>
> We also own a 94 Grand Cherokee 318 V8 and have often noticed the dip
> stick accuracy seems to be sensitive to shut-down time and vehicle
> angle.

They all are. Especially when it's cold outside.

> Last week it showed 1 Qt low so I added one. A couple of days ago I
> checked the oil level and it is showed ONE OVER and the oil pressure
> gauge shoots right over to max pressure after startup and doesn't
> waver from max until the engine shuts down. We don't know when the
> gauge began reading max only...

When you check oil level make sure you wait at least 10 min after shutdown
of a warm engine. That ensures all the oil has drained down. 1 qt over
shouldn't be a problem, just don't do it all the time. I check oil level
in the morning before heading out.

> I've drained one liter- clean oil- no water... Changed the filter -
> the old one came out EMPTY... Still the gauge shoots and stays at
> max.

By empty, do you mean bone dry or slightly filled. That can be the bypass
valve being cocked up inside the filter. Stay away from Fram filters, they
are not good oil filters.

Pegged pressure without a dead engine tells me your sender is shot. Time
to get a new oil pressure sender, but first check to make sure the wire
hasn't been knocked off the sender. Should run about $31 at NAPAonline or
chryslerpartsdirect.



--
-- 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!

Re: Grand Cherokee Oil Pressure
 

On Jan 12, 6:36 pm, "DougW" <I.only.read.use...@invalid.address>
wrote:
> jim.c.christiansen wrote:
> > Man, I'm having a go with my Jeeps this month.
>
> > We also own a 94 Grand Cherokee 318 V8 and have often noticed the dip
> > stick accuracy seems to be sensitive to shut-down time and vehicle
> > angle.
>
> They all are. Especially when it's cold outside.
>
> > Last week it showed 1 Qt low so I added one. A couple of days ago I
> > checked the oil level and it is showed ONE OVER and the oil pressure
> > gauge shoots right over to max pressure after startup and doesn't
> > waver from max until the engine shuts down. We don't know when the
> > gauge began reading max only...
>
> When you check oil level make sure you wait at least 10 min after shutdown
> of a warm engine. That ensures all the oil has drained down. 1 qt over
> shouldn't be a problem, just don't do it all the time. I check oil level
> in the morning before heading out.
>
> > I've drained one liter- clean oil- no water... Changed the filter -
> > the old one came out EMPTY... Still the gauge shoots and stays at
> > max.
>
> By empty, do you mean bone dry or slightly filled. That can be the bypass
> valve being cocked up inside the filter. Stay away from Fram filters, they
> are not good oil filters.
>
> Pegged pressure without a dead engine tells me your sender is shot. Time
> to get a new oil pressure sender, but first check to make sure the wire
> hasn't been knocked off the sender. Should run about $31 at NAPAonline or
> chryslerpartsdirect.
>
> --
> -- 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!

One qt over is ok? Won't that cause foaming and lack of lubrication?

Greg

Re: Grand Cherokee Oil Pressure
 

jerryg wrote:
> On Jan 12, 6:36 pm, "DougW" <I.only.read.use...@invalid.address>
> wrote:
>> jim.c.christiansen wrote:
>>> Man, I'm having a go with my Jeeps this month.
>>
>>> We also own a 94 Grand Cherokee 318 V8 and have often noticed the
>>> dip stick accuracy seems to be sensitive to shut-down time and
>>> vehicle angle.
>>
>> They all are. Especially when it's cold outside.
>>
>>> Last week it showed 1 Qt low so I added one. A couple of days ago I
>>> checked the oil level and it is showed ONE OVER and the oil pressure
>>> gauge shoots right over to max pressure after startup and doesn't
>>> waver from max until the engine shuts down. We don't know when the
>>> gauge began reading max only...
>>
>> When you check oil level make sure you wait at least 10 min after
>> shutdown of a warm engine. That ensures all the oil has drained
>> down. 1 qt over shouldn't be a problem, just don't do it all the
>> time. I check oil level in the morning before heading out.
>>
>>> I've drained one liter- clean oil- no water... Changed the filter -
>>> the old one came out EMPTY... Still the gauge shoots and stays at
>>> max.
>>
>> By empty, do you mean bone dry or slightly filled. That can be the
>> bypass valve being cocked up inside the filter. Stay away from Fram
>> filters, they are not good oil filters.
>>
>> Pegged pressure without a dead engine tells me your sender is shot.
>> Time to get a new oil pressure sender, but first check to make sure
>> the wire hasn't been knocked off the sender. Should run about $31 at
>> NAPAonline or chryslerpartsdirect.
>>
>> --
>> -- 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!
>
> One qt over is ok? Won't that cause foaming and lack of lubrication?

It's darn close, once the engine is running the Jeep's oil pan is
sufficent to handle the extra quart without getting in contact
with the crankshaft. Wouldn't make it a habbit though.

--
DougW

Re: Grand Cherokee Oil Pressure
 

On Jan 12, 7:16 pm, "DougW" <I.only.read.use...@invalid.address>
wrote:
> jerryg wrote:
> > On Jan 12, 6:36 pm, "DougW" <I.only.read.use...@invalid.address>
> > wrote:
> >> jim.c.christiansen wrote:
> >>> Man, I'm having a go with my Jeeps this month.
>
> >>> We also own a 94 Grand Cherokee 318 V8 and have often noticed the
> >>> dip stick accuracy seems to be sensitive to shut-down time and
> >>> vehicle angle.
>
> >> They all are. Especially when it's cold outside.
>
> >>> Last week it showed 1 Qt low so I added one. A couple of days ago I
> >>> checked the oil level and it is showed ONE OVER and the oil pressure
> >>> gauge shoots right over to max pressure after startup and doesn't
> >>> waver from max until the engine shuts down. We don't know when the
> >>> gauge began reading max only...
>
> >> When you check oil level make sure you wait at least 10 min after
> >> shutdown of a warm engine. That ensures all the oil has drained
> >> down. 1 qt over shouldn't be a problem, just don't do it all the
> >> time. I check oil level in the morning before heading out.
>
> >>> I've drained one liter- clean oil- no water... Changed the filter -
> >>> the old one came out EMPTY... Still the gauge shoots and stays at
> >>> max.
>
> >> By empty, do you mean bone dry or slightly filled. That can be the
> >> bypass valve being cocked up inside the filter. Stay away from Fram
> >> filters, they are not good oil filters.
>
> >> Pegged pressure without a dead engine tells me your sender is shot.
> >> Time to get a new oil pressure sender, but first check to make sure
> >> the wire hasn't been knocked off the sender. Should run about $31 at
> >> NAPAonline or chryslerpartsdirect.
>
> >> --
> >> -- DougW -- 93 ZJ 4.0http://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!
>
> > One qt over is ok? Won't that cause foaming and lack of lubrication?
>
> It's darn close, once the engine is running the Jeep's oil pan is
> sufficent to handle the extra quart without getting in contact
> with the crankshaft. Wouldn't make it a habbit though.
>
> --
> DougW- Hide quoted text -
>
> - Show quoted text -

My wife has a 06 Grand and our mechanic overfilled it by about a
quart. I called him the day after, he came to my house personally to
check the level, said we prolly shouldn't drive it, and had us bring
it in to his shop so they could drain some of it. Well I own a 95
Wrangler that I do ALL the maintenence on, and fiqured letting my
local mechanic change the oil in our Grand(not these instant oil
change places) would be ok. Well, it pays to do it yourself.

Greg

Re: Grand Cherokee Oil Pressure
 

jim.c.christiansen@gmail.com wrote:
> Man, I'm having a go with my Jeeps this month.
>
> We also own a 94 Grand Cherokee 318 V8 and have often noticed the dip
> stick accuracy seems to be sensitive to shut-down time and vehicle
> angle.

Tends to be true of pretty much every vehicle. Possibly one with oil
pan baffles might be less likely to be thusly sensitive.

> Last week it showed 1 Qt low so I added one. A couple of days ago I
> checked the oil level and it is showed ONE OVER and the oil pressure
> gauge shoots right over to max pressure after startup and doesn't
> waver from max until the engine shuts down. We don't know when the
> gauge began reading max only...
>
> I've drained one liter- clean oil- no water... Changed the filter -
> the old one came out EMPTY... Still the gauge shoots and stays at
> max.
>
> There are no rattles and the engine runs as always before- perfectly.
>
> What do you think: sender unit or something serious like a partially
> spun bearing?

Before you panic, swap the pressure sensor. They're cheap and
notoriously fragile.

Then panic.