Question about oil pressure gauge in 04 Rubicon

BRING IT BACK!!!

I had the reverse problem, at around 30k, seemed like i was losing pressure. Mine turned out to be a bad guage.

I'll bet he has a cheap Fram filter in it, or the equivalent.

Earle

Thank you guys for replying. I REALLY appreciate all the info!

I have a 2005 rubicon 8k miles my jeep does the same thing. I too was just starting to wonder. I was thinking of going to a dealer and test driving a new jeep and see if it did the same thing. Or take it in to the dealer.

I dont recall if it always did this or not. Maybe I am worrying over nothing and the guage is slow. Let me know what you find out.

snipped-for-privacy@webtv.net wrote:

I have a 2005 rubicon 8k miles my jeep does the same thing. I too was just starting to wonder. I was thinking of going to a dealer and test driving a new jeep and see if it did the same thing. Or take it in to the dealer.

I dont recall if it always did this or not. Maybe I am worrying over nothing and the guage is slow. Let me know what you find out.

snipped-for-privacy@webtv.net wrote:

Sorry for the top post, but:

Back when I used to drive Slant 6 cars (1980-1999), I noticed the following:

1. On the Slant 6, just like the 4.0 Jeep, the filter sits upside down so that gravity tends to make the oil flow back out of the filter and into the pan when not running.

1. Despite the claims made here and elsewhere, based on my oil lights on

3 vehicles over almost 20 years, Fram filters tended to hold pressure overnight better than AC, Motocraft, Mopar, and a few others. Purelator was an exception...they always worked.

1. Some, like AC, would work fine until a good long run at high speed. After that, they would cause a delay in putting out the oil light when starting. Some (mixed brands) had the same behavior from the first start.

2. I finally gave up on the Slant 6s and used Frams. Sure, the construction of the anti-drainback valve may appear flimsy, but it always worked unlike most others. Perhaps that cardboard/rubber flap actually works better in service than the more logical systems used in other filters. Several times, after an oil change, I had to replace "Xbrand" filters with Fram to hold oil in the filter overnight. The Frams always assured a quick oil light turnoff until they got replaced at the next oil change.

1. On my XJ, after reading the assorted oil filter tests on the web, I switched to Purelator and have not had a problem. But the only stores that carry them locally, (Pep Boys) tend to run out of the proper filter, so I have to buy several when they are actually in stock. I'd use Fram again in a pinch.

2. I'm not commenting on the filter medium itself. Just the anti-drainback function.

Best Regards,

DAve

Earle Hort> I'll bet he has a cheap Fram filter in it, or the equivalent.

I seen on the web where the Jeep 4 liter will accept the Ford V-8 filters (FL-1)

The 4.0 liter engine originally used a PH3985 or equivalent, with a metric filter adapter having 20mm-1.5mm thread. In 1991, Jeep switched to a PH16 with 3/4-16, which is what many Chrysler products used. This appears to have the same base as the larger PH8, used on older Ford and Chrysler engines.

Can you substitute the one quart filter for the half quart filter? I suppose so, but I have never done it.

Earle

I hear you Bill. A bit less surface area is of course counterbalanced by more frequent oil and filter changes. Most of my vehicles see relatively few miles vs. months, but nearly all of it in Los Angeles traffic. So, I go with 4 months/3000 miles.

Interestingly, on the carb engines, oil would get dirty much faster than more modern FI engines with similar age/mileage. The newer engines certainly appear to reach operating temp faster, and this may be the difference, not spewing as much unburned gas into the oil during warm up.

Anyway, I've nearly stopped doing my own oil. Living in an apartment these days with no good place to do it, it is just simpler to go to the local shop for those messy fluid draining chores. I still do about 1 in

3 so that I'm sure to crawl under the old XJ and have a look around. You never know what you will find lurking...

Best Regards,

DAve

L.W.(Bill) Hughes III wrote:

If your case is pre-Allied Signal, you should be OK.

Yup, I have a Motorcraft FL-1 filter on mine. XJ's would have some problem because of the right angle filter adaper, not much room in the engine bay for a larger filter.

??? Filter sits horizontal, not upside down on the 4.0L.

I've found the opposite. For my Super Duty V10, the Mobil 1 filter actually had worse start-up pressure than anything. I use Motorcraft filters, which I believe are made by Purolator.

Consider that what you may be seeing is the Frams filter so poorly that the oil reaches pressure downstream of the filter sooner .

Then what's the point of a filter?