Oil change - pressure change?
Hey guys. Decided to do my own oil changes now, which I don't know why I wouldn't have decided to do it sooner with everything else that I have tackled myself with the XJ.
Anyway, last time my oil was changed at the typical quick lube place, Pennzoil was used, pretty sure I had them put in 5W30 as winter was approaching. They used a M3600 Engine Guard II filter.
Before I changed the oil my pressure was around 40-60 accelerating and 20-40 idling IIRC.
Today I changed the oil, figured Castrol High Milage 10W30 would be fine since my '98 has 196k on the ticker. I used a Fram Tough Guard TG-16 filter. I noticed the Fram filter is larger in diameter than the old Engine Guard II filter.
Now on to my question: with the previous oil/filter used and the new oil/filter installed should one expect a 10lb.+ drop in oil pressure? I am experiencing less pressure than I had before. I wonder if that is due to the filter being larger, or to the new weight oil. I do not see any leaks anywhere.
One other thing I noticed is that the oil cap on the engine seemed to just spin around and not positively stop as if it was fully seated when I put it back on. I have had the cap off before and never remember it being like that when I put it back on. Is that normal for the cap?
Any ideas? Thanks guys
Anyway, last time my oil was changed at the typical quick lube place, Pennzoil was used, pretty sure I had them put in 5W30 as winter was approaching. They used a M3600 Engine Guard II filter.
Before I changed the oil my pressure was around 40-60 accelerating and 20-40 idling IIRC.
Today I changed the oil, figured Castrol High Milage 10W30 would be fine since my '98 has 196k on the ticker. I used a Fram Tough Guard TG-16 filter. I noticed the Fram filter is larger in diameter than the old Engine Guard II filter.
Now on to my question: with the previous oil/filter used and the new oil/filter installed should one expect a 10lb.+ drop in oil pressure? I am experiencing less pressure than I had before. I wonder if that is due to the filter being larger, or to the new weight oil. I do not see any leaks anywhere.
One other thing I noticed is that the oil cap on the engine seemed to just spin around and not positively stop as if it was fully seated when I put it back on. I have had the cap off before and never remember it being like that when I put it back on. Is that normal for the cap?
Any ideas? Thanks guys
Senior Member
Joined: Nov 2012
Posts: 918
Likes: 6
From: Harrisburg, Pennsylvania
Year: 1995
Model: Cherokee
Engine: 4.0L HO
Wix/NAPA gold, Purolator/Bosch/MANN, Baldwin, Hastings, Mobil 1, and Motorcraft are all good options. You can also run the larger Motorcraft FL-1A/ Purolator L/PL30001, Wix 51515/ NAPA 1515, etc. which offers more filter area and oil capacity (it is about twice the size of the OE filter, this was the stock size filter for the Ford 302/351). The Motorcraft FL-1A is excellent for the price, they are basically a Purolator PureOne filter in a standard can. The Purolator Classic is also far superior to Fram (both "Orange-Can" and Tough-Guard) for about the same price as an "Orange-Can" Fram.
Senior Member
Joined: Jan 2015
Posts: 641
Likes: 1
From: Anderson, SC
Year: 1999
Model: Cherokee
Engine: 4.0
Don't worry about the pressure, that sounds fine.
Lol at Fram.
As for oil cap, they are designed pretty poorly. I would suggest taking it off, popping it apart, and plasti-welding the two pieces together to make it act like every other fully functioning oil cap out there.
Lol at Fram.
As for oil cap, they are designed pretty poorly. I would suggest taking it off, popping it apart, and plasti-welding the two pieces together to make it act like every other fully functioning oil cap out there.
Senior Member
Joined: Feb 2011
Posts: 897
Likes: 2
From: NJ
Year: 2004 WJ, 1998 XJ
Model: Grand Cherokee(WJ)
Engine: 4.7 HO
Same thing happened to me when I used Fram. It is no joke or myth with these filters, they blow. Changed the filter and never had a loss of pressure again. I use Napa Gold's now.
My oil cap did the same thing as yours until it popped off somewhere. I just bought a replacement at Napa for $6 or so. It's a basic screw on cap, no springs or anything like the OEM one.
My oil cap did the same thing as yours until it popped off somewhere. I just bought a replacement at Napa for $6 or so. It's a basic screw on cap, no springs or anything like the OEM one.
Senior Member
Joined: Sep 2014
Posts: 580
Likes: 0
From: Saginaw Mi area
Year: 1994
Model: Cherokee
Engine: 4.0
I haven't used a Fram filter in years, but don't remember any problems with them in the old days ..
But.....every forum I'm on advises against using them. Maybe in later years the Chinese didn't use good stuff to make them.....
But.....every forum I'm on advises against using them. Maybe in later years the Chinese didn't use good stuff to make them.....
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CF Veteran
Joined: Feb 2010
Posts: 12,367
Likes: 23
From: Oroville, CA
Year: 1995
Model: Grand Cherokee
Engine: 4.0 with all of the noise and clatter
Senior Member
Joined: Sep 2014
Posts: 625
Likes: 3
From: Austintown, OH
Year: 2000
Model: Cherokee
Engine: 4.0
The cap has two parts. Is it clicking when you spin it on?
There are teeth on the bottom portion inside to let you tighten it but not over tighten it. Kinda like a gas cap.
There are teeth on the bottom portion inside to let you tighten it but not over tighten it. Kinda like a gas cap.
Senior Member
Joined: Nov 2012
Posts: 918
Likes: 6
From: Harrisburg, Pennsylvania
Year: 1995
Model: Cherokee
Engine: 4.0L HO
^This, while your pressure is still within spec (albeit on the low end of spec) and the Fram isn't likely to do any major damage in 3k mi (unless it has a major internal failure which has been known to happen due to the card-board end caps and plastic by-pass valve), since you can get a decent filter for $3-$4 and it takes all of 5 min to change it, I'd go ahead and change it out ASAP (especially if you run oil change intervals beyond 3k mi).
Well, to let everyone know, I do not hate my engine. Now that that is out of the way here is todays events:
Picked up a Purolator Classic and an extra quart of Castrol High Milage. Drove home this afternoon and the pressure dropped again so when I got home I spent the time that it was cooling down replacing the spark plugs.
Eventually I swapped the Fram Tough Guard for the Purolator and topped her off. Noticed that I gained about 5-8 lbs of pressure. Guess I'll stay away from the Frams.
Now to wait for my heater core and evap core to arrive to start on the real fun...
Picked up a Purolator Classic and an extra quart of Castrol High Milage. Drove home this afternoon and the pressure dropped again so when I got home I spent the time that it was cooling down replacing the spark plugs.
Eventually I swapped the Fram Tough Guard for the Purolator and topped her off. Noticed that I gained about 5-8 lbs of pressure. Guess I'll stay away from the Frams.
Now to wait for my heater core and evap core to arrive to start on the real fun...
Member
Joined: Jun 2013
Posts: 138
Likes: 0
From: Lawrence
Year: 1997
Model: Cherokee
Engine: 4.0 straight 6
Gotta say this is the first thing i learned from this forum. Shell Rotella and either wix, mopar, or napa gold filter. I made the mistake of using a fram with my first oil change. It killed my oil pressure at idle. Made the switch...i personally use shell Rotella T5 and a mopar filter...and the problem was gone.
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