Pennzoil Oil
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Junior Member
Joined: Mar 2009
Posts: 47
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Year: 2001
Model: Cherokee
Engine: 4.0 L
I was wondering why people say not to use Pennzoil Oil. Some posts on here say jeep engines don't like it. I'm due for a oil change in my 01 XJ and I'm a little hesitant to use Pennzoil now.
CF Veteran
Joined: May 2009
Posts: 1,844
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From: Glen Burnie, MD
Year: 1994
Model: Cherokee
Engine: 4.0 H.O. K&N, Borla headers, custom down pipe, magnaflow hi-flo cat, flowmaster to turn down tip
the 4.0 motors (especially pre 97 motors) tend not to like synthetics, because they were not built for them. basically, if you have a leak that you have never seen before, the synthetic oil will find it cause it likes to find its way through every nook and cranny. just keep to regular oil, or synthetic blends. i use the Valvoline High Mileage 10w30, i have no problems with burn off, smoking, or oil pressure. but i have never heard problems with Pennzoil for these motors, but i myself have not and will not use it. i like the Valvoline for my jeep and the Castrol EDGE for my trans am.
Seasoned Member
Joined: Feb 2011
Posts: 284
Likes: 0
From: jackson nj
Year: 1990
Model: Cherokee
Engine: 4.0
ive allways run synthetic motor oil( i run castol gtx high milage) since ive owned it. i tryied penzoil didnt care for it motor didnt feel as good as it does with the castol oil
Seasoned Member
Joined: Jun 2011
Posts: 276
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From: Van Buren Arkansas, was Joplin Missouri
Year: 1990
Model: Cherokee
Engine: 4.0L
I run mobil conventional 10w30. I have a rear main that leaks but it slowed way down since I changed from reg valvoline. I also use Lucas.
Senior Member
Joined: Apr 2011
Posts: 746
Likes: 3
From: here today gone tomorrow
Year: 1996
Model: Cherokee
Engine: 4.0
I've run full synthetic 10W-30 in my '96 from 18K miles to the present 156k. Most of those miles were with Valvoline, but at least a couple were with Pennzoil, Shell Rotella, and Now Mobil 1. I've not had any issues that could be attributed to oil type, weight, or brand. I generally like to change around 5K, but sometimes go further, and I do not add between changes, and its never down more than 1/2 qt. This is all orignal gaskets and seals!
I have heard that Pennzoil has paraffin in it, and the heat of the 4.0 melts that into the oil passages, creating nasty deposits. At least that is what I have heard.
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CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
Didn't make it past 3 posts and the oil myths got started/revived.
Has anyone ever heard a motor say I don't like this oil or I luv this oil?
Has anyone ever heard a motor say I don't like this oil or I luv this oil?
Last edited by djb383; Jun 15, 2011 at 12:21 PM.
CF Veteran
Joined: Jun 2010
Posts: 2,117
Likes: 3
From: Ohio
Year: 1998
Model: Cherokee
Engine: 4.0 stock
No I have never heard an engine say "I don't like this oil". But it will usually let you know if it doesn't with various noises. Not usually due to the oil itself but the type of additives that are in it.
Pennzoil motor oil doesn't use paraffin. At least not anymore (dunno if they did at one time)
Dino oil is dino oil IMO... With all the outrageous claims made with all the different oils I tend to stick with what I know will work. I have used Mobil 1 for full synthetic use and what is on sale for dino oil.
Pennzoil motor oil doesn't use paraffin. At least not anymore (dunno if they did at one time)
Dino oil is dino oil IMO... With all the outrageous claims made with all the different oils I tend to stick with what I know will work. I have used Mobil 1 for full synthetic use and what is on sale for dino oil.
CF Veteran
Joined: Nov 2010
Posts: 1,275
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From: North Carolina
Year: 1999
Model: Cherokee
Engine: Gas
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Joined: Nov 2010
Posts: 5,841
Likes: 117
From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
People over-analyze brands of oil.
If you want to see a really obsessive discussion, check out "bobistheoilguy".
If you use a major brand of oil, either synthetic or dino, use the correct viscosity for the temperature range you are using the vehicle in, change it at a reasonable interval and don't use an el-cheapo filter, you will be just fine.
I've got other stuff to worry about.............
If you want to see a really obsessive discussion, check out "bobistheoilguy".
If you use a major brand of oil, either synthetic or dino, use the correct viscosity for the temperature range you are using the vehicle in, change it at a reasonable interval and don't use an el-cheapo filter, you will be just fine.
I've got other stuff to worry about.............
CF Veteran
Joined: Jun 2010
Posts: 2,117
Likes: 3
From: Ohio
Year: 1998
Model: Cherokee
Engine: 4.0 stock


