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  Topic Review (Newest First)
07-08-2019 07:10 PM
1998XJLtd Ran Valvoline 5w-30 and a Mopar -090 filter for first 150k. Last 25k or so has been Mobil1 5w-30 syn and same -090 filter you can find for $5 at Wal-Mart. Pushing 180,000 on the odometer and no issues.
07-02-2019 05:19 AM
75SV1
Quote:
Originally Posted by gutthans View Post
Good thought. I haven't run cats in years, so I don't worry about that.
I think Rotella has 1,000 to 1,200 ppm of Zinc. The XJs or older Jeeps use older catalytic technology. So, that amount of Zinc shouldn't plug them as quick. I think the 'newer' speced oils use molybdenum or such. And again, I'd agree that to heavy of an oil can cause problems and MPG decrease. I've run 15W-40 Rotella before. I did not have any issues. Others run it too. I ran Rotella 10W-30 in the past few years. If you engine does not leak, Rotella T6 5W-40 synthetic is a good choice. Shows good to better wear rates than a lot of other oils, according to Blackstone Labs.
06-27-2019 03:37 PM
gutthans
Quote:
Originally Posted by mukluk View Post
Be careful about using oil with "lots and lots of zinc" as this can easily lead to catalytic converter damage. Yes, flat tappet engines like the 4.0L need more ZDDP than more modern designs to prevent excessive valvetrain wear, but you can quickly reach a point of having too much of a good thing which can cause problems elsewhere.

Unless your bearings and oil pump are worn to where you can't keep pressure in spec, there's not much point in running oil heavier than 10w30 in these engines.
Good thought. I haven't run cats in years, so I don't worry about that.
06-27-2019 02:00 PM
mukluk Be careful about using oil with "lots and lots of zinc" as this can easily lead to catalytic converter damage. Yes, flat tappet engines like the 4.0L need more ZDDP than more modern designs to prevent excessive valvetrain wear, but you can quickly reach a point of having too much of a good thing which can cause problems elsewhere.

Unless your bearings and oil pump are worn to where you can't keep pressure in spec, there's not much point in running oil heavier than 10w30 in these engines.
06-27-2019 01:12 PM
gutthans
Quote:
Originally Posted by 75SV1 View Post
I like to use Shell Rotella. The do make 10W-30 and 10W40. I like to use a bit higher zinc levels. I do use a NAPA oil filter. I am running Rotella T6 presently. Its a synthetic. Still, nothing wrong with conventional oils.
"Hi-Mileage" oil tends to have the best zinc levels. I, however, am sold on Brad Penn Oils I get by the case from Summit. I run the 30w (Florida) Break-in Oil all year. LOTS & LOTS of ZINC. I researched that a looong time ago and did Valvoline Hi-mileage until I found Penn.
06-27-2019 12:25 PM
75SV1
Quote:
Originally Posted by gutthans View Post
May not be a 'brand' issue...More likely the weight of the Amsoil Race? What weight did you put in? What's your average temp there over the next 3 months?
I was thinking the same thing. I am not sure how heavy of an oil a 4.0L can take. I did have a Ford Contour with the 4 cylinder or was it my SVT. I used a 20W-50 in it, Mobil 1. It clattered a bunch. I didn't run that oil long. Ran OK after that. (not a bash on Mobil 1).

I like to use Shell Rotella. The do make 10W-30 and 10W40. I like to use a bit higher zinc levels. I do use a NAPA oil filter. I am running Rotella T6 presently. Its a synthetic. Still, nothing wrong with conventional oils.

Also, you might lose a few MPGs with a heavier oil.
06-21-2019 09:49 PM
gutthans
Quote:
Originally Posted by Markeje74 View Post
My 4.0 was nice and quiet on start up and run. I tried Amsoil Race this year because I use it in my bike and it's great. PLus a nap gold filter because I had it laying around. But now in the 4.0 I get the lifter clack on start up. What oil should I run to quiet this down? I do not remember what I had in before unfortunately. Pretty sure it was Pennzoil. I know I used a K&N oil filter.
May not be a 'brand' issue...More likely the weight of the Amsoil Race? What weight did you put in? What's your average temp there over the next 3 months?
06-21-2019 08:12 PM
wildbill23c My 98 says 5w-30, so that's what I use in it. Mine has the normal lifter clattering as well, not nearly as bad as the 2.9L V6 that's in my 1988 Ford Bronco 2 had before the engine was replaced though. Maybe add some zinc additive when you change the oil, that may help.
06-21-2019 07:57 PM
StrippedTorx You sure you’re putting enough oil in it?
06-21-2019 04:49 PM
biffgnar If you change it regularly use whatever is on sale at the parts store when you walk in.
06-19-2019 10:28 PM
mukluk Use your choice of name brand 10w30 or 5w30 oil that meets MS-6395 or API SN.
06-19-2019 06:40 AM
Markeje74
Oil recommendation for 4.0

My 4.0 was nice and quiet on start up and run. I tried Amsoil Race this year because I use it in my bike and it's great. PLus a nap gold filter because I had it laying around. But now in the 4.0 I get the lifter clack on start up. What oil should I run to quiet this down? I do not remember what I had in before unfortunately. Pretty sure it was Pennzoil. I know I used a K&N oil filter.

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