XJ oil pressure reading?

Just bought an 86 Cherokee 2.8 and oil pressure readings seem weird.

I've just read all the postings covering low oil pressure. (A lot of
postings.) The sender often seems be the prime suspect.

When I first start the engine the gauge shows about 40 pounds and
drops to about zero before there's even much heat in the engine. It
stays there if I run the rpm up to 3500 or so. No warning light comes
on. There are no rod or lifter rattles or knocks that I can hear.
Nothing that sounds like main bearing "clunks" either.

Odometer says about 165k. Seller says it has only been started every
couple of months for about 1+ years. Hasn't been driven because of the
oft mentioned black smoke,stumbling throttle response, rough idle
thingie, whatever that is. She claims no history of low oil pressure
problems. Oil was down a quart and dirty when first checked.

I'm afraid to drive this thing home.

Suggestions?

Thanks,

Lance Ferguson

Have a tow service bring it to your home. Then work on it at your leisure.
Does this beast have a carburetor? Black smoke could just be a stuck or
non-working choke. Get a new sending unit. They are cheap.

Earle

"Dutchmajician" > wrote in message
oups.com...
> Just bought an 86 Cherokee 2.8 and oil pressure readings seem weird.
>
> I've just read all the postings covering low oil pressure. (A lot of
> postings.) The sender often seems be the prime suspect.
>
> When I first start the engine the gauge shows about 40 pounds and
> drops to about zero before there's even much heat in the engine. It
> stays there if I run the rpm up to 3500 or so. No warning light comes
> on. There are no rod or lifter rattles or knocks that I can hear.
> Nothing that sounds like main bearing "clunks" either.
>
> Odometer says about 165k. Seller says it has only been started every
> couple of months for about 1+ years. Hasn't been driven because of the
> oft mentioned black smoke,stumbling throttle response, rough idle
> thingie, whatever that is. She claims no history of low oil pressure
> problems. Oil was down a quart and dirty when first checked.
>
> I'm afraid to drive this thing home.
>
> Suggestions?
>
> Thanks,
>
> Lance Ferguson
>

Be sure to throw a mechanical gauge on it before
replacing the sending unit. A lot of auto parts stores will 'lend' you the
gauge..


"Earle Horton" > wrote in message
om...
> Have a tow service bring it to your home. Then work on it at your
> leisure.
> Does this beast have a carburetor? Black smoke could just be a stuck or
> non-working choke. Get a new sending unit. They are cheap.
>
> Earle
>
> "Dutchmajician" > wrote in message
> oups.com...
>> Just bought an 86 Cherokee 2.8 and oil pressure readings seem weird.
>>
>> I've just read all the postings covering low oil pressure. (A lot of
>> postings.) The sender often seems be the prime suspect.
>>
>> When I first start the engine the gauge shows about 40 pounds and
>> drops to about zero before there's even much heat in the engine. It
>> stays there if I run the rpm up to 3500 or so. No warning light comes
>> on. There are no rod or lifter rattles or knocks that I can hear.
>> Nothing that sounds like main bearing "clunks" either.
>>
>> Odometer says about 165k. Seller says it has only been started every
>> couple of months for about 1+ years. Hasn't been driven because of the
>> oft mentioned black smoke,stumbling throttle response, rough idle
>> thingie, whatever that is. She claims no history of low oil pressure
>> problems. Oil was down a quart and dirty when first checked.
>>
>> I'm afraid to drive this thing home.
>>
>> Suggestions?
>>
>> Thanks,
>>
>> Lance Ferguson
>>
>
>

Well, mystery solved. I couldn't find a mechanical gage to test the
oil pressure. It occured to me to buy an aftermarket kit to mount an
auxillary gage and premanently replace the old sender and gage. This
avoided replacing a part with a bad failure reputation with another of
the same.

It cost 16 bucks.

The oil pressure is really just fine.

Lance


-------------------------------------------------------------------------------------------------------------------------------------------------------.
> > "Dutchmajician" > wrote in message
> roups.com...
> >> Just bought an 86 Cherokee 2.8 and oil pressure readings seem weird.
>
> >> I've just read all the postings covering low oil pressure. (A lot of
> >> postings.) The sender often seems be the prime suspect.
>
> >> When I first start the engine the gauge shows about 40 pounds and
> >> drops to about zero before there's even much heat in the engine. It
> >> stays there if I run the rpm up to 3500 or so. No warning light comes
> >> on. There are no rod or lifter rattles or knocks that I can hear.
> >> Nothing that sounds like main bearing "clunks" either.
>
> >> Odometer says about 165k. Seller says it has only been started every
> >> couple of months for about 1+ years. Hasn't been driven because of the
> >> oft mentioned black smoke,stumbling throttle response, rough idle
> >> thingie, whatever that is. She claims no history of low oil pressure
> >> problems. Oil was down a quart and dirty when first checked.
>
> >> I'm afraid to drive this thing home.
>
> >> Suggestions?
>
> >> Thanks,
>
> >> Lance Ferguson

On 4 Apr 2007 09:51:44 -0700, "Dutchmajician"
> wrote:

>Well, mystery solved. I couldn't find a mechanical gage to test the
>oil pressure. It occured to me to buy an aftermarket kit to mount an
>auxillary gage and premanently replace the old sender and gage. This
>avoided replacing a part with a bad failure reputation with another of
>the same.
>
>It cost 16 bucks.
>
>The oil pressure is really just fine.


Nice solution. That 2.8 is a GM engine and basically a sturdy design
(it was morphed into a 3.1 and a 3.4 too) and if you keep it full of
coolant and clean oil it should run a long time.
-----------------
TheSnoMan.com

Won't it start throwing codes of the computer thinks the engine has no oil
pressure?


"Dutchmajician" > wrote in message
ups.com...
> Well, mystery solved. I couldn't find a mechanical gage to test the
> oil pressure. It occured to me to buy an aftermarket kit to mount an
> auxillary gage and premanently replace the old sender and gage. This
> avoided replacing a part with a bad failure reputation with another of
> the same.
>
> It cost 16 bucks.
>
> The oil pressure is really just fine.
>
> Lance
>
>
> -------------------------------------------------------------------------------------------------------------------------------------------------------.
>> > "Dutchmajician" > wrote in message
>> roups.com...
>> >> Just bought an 86 Cherokee 2.8 and oil pressure readings seem weird.
>>
>> >> I've just read all the postings covering low oil pressure. (A lot of
>> >> postings.) The sender often seems be the prime suspect.
>>
>> >> When I first start the engine the gauge shows about 40 pounds and
>> >> drops to about zero before there's even much heat in the engine. It
>> >> stays there if I run the rpm up to 3500 or so. No warning light comes
>> >> on. There are no rod or lifter rattles or knocks that I can hear.
>> >> Nothing that sounds like main bearing "clunks" either.
>>
>> >> Odometer says about 165k. Seller says it has only been started every
>> >> couple of months for about 1+ years. Hasn't been driven because of the
>> >> oft mentioned black smoke,stumbling throttle response, rough idle
>> >> thingie, whatever that is. She claims no history of low oil pressure
>> >> problems. Oil was down a quart and dirty when first checked.
>>
>> >> I'm afraid to drive this thing home.
>>
>> >> Suggestions?
>>
>> >> Thanks,
>>
>> >> Lance Ferguson
>
>

On Wed, 4 Apr 2007 19:37:44 -0400, "billy ray"
> wrote:

>Won't it start throwing codes of the computer thinks the engine has no oil
>pressure?

Not on a 86
-----------------
TheSnoMan.com