I recently bought a '95 Grand Cherokee and I have noticed that the oil pressure is real high at start up(especially when the temp. is cold) but goes down as it warms up. by high it is almost to the high end of the gauge. Is this normal?

How high is high? Mine '96 I6 runs usually between 55-60 when the car starts and goes down a little after running a while.

How high is high? Mine '96 I6 runs usually between 55-60 when the car starts and goes down a little after running a while.

How high is high? Mine '96 I6 runs usually between 55-60 when the car starts and goes down a little after running a while.

What weight of oil is in the Jeep? If it's way too heavy it might cause the problem you have.

What engine do you have? In my 4.0, the pressure is usually about 50-55 at startup (or on the highway) and about 45 at idle.

I use 10/30 and since we have been having some pretty warm weather I don't belive it is that and it was changed not long ago. It usually runs around 65-70 at start then down to 40-50 after it warms up. I know my Ranger ran the same pressure all the time(whithin 5psi) cold or hot. I have the 5.2litre.:banghead:

From the numbers you posted, I don't think you have much to worry about.

It is normal for an engine with the age on it that you must have to lose oil pressure after warmup.

Two things that I would suggest if you continue to be concerned are:

Have the oil pressure checked with a mechanical gauge.
Change out the oil pressure sending unit (it's relatively inexpensive and they are a known weak spot) It's located next to the distributor on the drivers side.JD

Thanks for the info, I am really nototo concerned at this time I was just curious.I was slightly concerned at first but it runs good so I just figured it was one of foibles(sp)

Quick question, I know Ive asked this before but the problem seems to be getting worse. What is the proper operating range for oil pressure on a 96 I6? It seems to be fine when just starting (approx 50), but then after running for awhile and coming to a stop it drops down to 20, sometimes now just below! For some reason it just seems too much of a drop. The operating temp stays right at 12 o'clock the whole time and there havent been any noticible performane changes or issue. The oil level is correct (by the dipstick). Im using 10W30 Synthetic with 140k miles. This is after about 30 minutes of driving.

From this website: http://www.wjjeeps.com/engine.htm

13 psi minimum at idle, and 37-75 psi above 1600 rpm.

My 94 ZJ 5.2L on start up is about 70 PSI, then drops down to about 40-45 PSI after warms up. So I would say this is normal.

Quick question, I know Ive asked this before but the problem seems to be getting worse. What is the proper operating range for oil pressure on a 96 I6? It seems to be fine when just starting (approx 50), but then after running for awhile and coming to a stop it drops down to 20, sometimes now just below! For some reason it just seems too much of a drop. The operating temp stays right at 12 o'clock the whole time and there havent been any noticible performane changes or issue. The oil level is correct (by the dipstick). Im using 10W30 Synthetic with 140k miles. This is after about 30 minutes of driving.


20 PSI does seem low, altho still within a safe range. Could be a worn oil pump/partially clogged screen. Might want to have the engine flushed with a chemical flush, it will break down all the sludge in the engine that has built up over the years.

20 PSI does seem low, altho still within a safe range. Could be a worn oil pump/partially clogged screen. Might want to have the engine flushed with a chemical flush, it will break down all the sludge in the engine that has built up over the years.

You might try this stuff:

www.auto-rx.com

I did, and it works as advertised. :thumbsup:

Fred,

Did you buy that stuff online or were you able to find it stocked on a local shelf?

Fred,

Did you buy that stuff online of were you able to find it stocked on a local shelf?


Online. It's a fairly new product (less than 2 years I think) and hasn't made its way to stores.

You can read more about it (and other lube stuff) at: www.bobistheoilguy.com

I've got a ticky lifter. No biggie really, I can tell you exactly at which billboard it will stop doing it in the morning when I leave the house but it got me wondering if that stuff might be worth a look.

What I did do almost right away when I got my hands on the vehicle was switch to a Motorcraft FL-1A oil filter. It's made for the Mustang 5.0 but it fits the Jeep 4.0 perfectly. I don't think I saw higher than 40 lbs ever with whatever oem spec filter was on there and now I idle at 20 warm and hit 50 on the road.

At 194K, you'd need two applications, but a $50 investment will be worth it IMO....just be sure to follow the directions and you'll be good.

IMHO any jeep with 194K is worth $50. :)

! !

Stupid Question, on that site for the engine cleaner it says to replace the oilfilter prior to the first stage. I just changed my oil with synthetic and dont want to drain it out in order to add on a new filter. NOw heres the stupid question, Ive changed the filter everytime Ive changed the oil, can I replace that without losing a good amount of oil, never done this before with the oil previously being drained, I assume that the majority of the oil will be in the pan if I let it sit awhile, and I might lose about a quart changing the oil filter.

Apparently some of them drain into a clean container then change the filter, while others just do a quick swap. I guess it depends on the engine design and how much oil is above the filter (and how fast you are lol).

In both cases, they said they need to add a bit to make up what was caught in the filter.

FYI I never forgot this .... My first bottle came today. I'll start a new post about why I got some.



You might try this stuff:

www.auto-rx.com

I did, and it works as advertised. :thumbsup:

Snake oil. ;)

Snake oil. ;)

As I said, I used the product and it worked as advertised.

We'll see if his noisy lifter quiets down or not....

Well we are going to find out. :popcorn:

:popcorn:




:cwm27: