Hello all. New here but not to wrenching. Just installed a reman 4.0 in my wifes 2000 Jeep TJ. Filled it up with Lucas 30w break in oil supplied my remanufacturer and told to change after 500 miles. We're at that point now and looking to do it's first oil change with Mopar filter but unsure on the oil. Have been a diehard Valvoline user since Pennzoil cost me a engine in my 66 Pontiac GTO way back when coffee was a dime. Now to current times. I've heard so much lately about Zinc and it's benefits> Is it really due the hype? Also a lot about the high mileage synthetics and the benefits(?) they provide. I just want to find the best 10-30 oil, recommended by rebuilder for 7 yr warranty, that will keep this old girl alive. She's just a mostly in town girl but will occasionally see some of Nevada's dirt roads. Any thought's and input appreciated. Thank you.
New engine Jeep 4.0L - which oil?
- Thread starter moosemeadows
- Start date
The brand of oil is less important than keeping her full and clean. Heavy Duty Engine Oil (HDEO) for diesels tends to have the higher levels of zinc and phosphorous if that is important to you, though, a regular gasoline engine will be fine as well. Personally, I would not worry about looking for the highest zinc levels because modern oil additives have been designed to provide high levels of anti-wear protection with today's more modest zinc levels.
You can use any certified synthetic oil from Xw-30 to Xw-40 in your engine with excellent results. Euro type oils are popular on this sight as they are designed for longer change intervals and must meet more stringent specifications. The only difference with the high mileage oils you mentioned are additional seal softeners and conditioners to help stop or reduce leaking. If it's not leaking yet, you don't need them but they won't hurt anything, either.
You will get a lot of recommendations in this thread, and none of them will be "wrong."
You can use any certified synthetic oil from Xw-30 to Xw-40 in your engine with excellent results. Euro type oils are popular on this sight as they are designed for longer change intervals and must meet more stringent specifications. The only difference with the high mileage oils you mentioned are additional seal softeners and conditioners to help stop or reduce leaking. If it's not leaking yet, you don't need them but they won't hurt anything, either.
You will get a lot of recommendations in this thread, and none of them will be "wrong."
There is some hype behind "zinc". IOW more is not better. Anyways if you're looking for passenger car oils which tend to run higher in zinc then choose any euro spec 5w30 or 5w40 and can be very affordable. Buy whichever is cheaper.
Examples,
Mobil 1 FS (30, 40 grade)
M1 ESP 30 or 40 grade)
Valvoline Euro 5w40
Pennzoil (aka Shell) Euro 5w40
Shell Euro L 5w30
Castrol Edge A3/B4 30 or 40 grade
10w30's are going to be hard to find with the latest additive packages. Your builder is recommending 10w30 rather than requiring. Euro spec 5w40's are not very heavy anyways.
High mileage oil shouldn't be needed on a reman because all the seals should be new.
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Whichever one is least expensive at Walmart.
Believe me, you will get some wrong recommendations.
We'll see.
After the cam break-in, you really don't need a high zinc oil for a 4.0L. The valve spring pressures are low enough where it won't matter. A stroker with an aggressive cam is a different story.
I run Valvoline Maxlife synthetic 5w30 in my 98 TJ 4.0L, it seems to be one of the quietest oils I've run in it. A friend also has a '97 ZJ Grand Cherokee 4.0L that has over 300k miles on plain old Valvoline conventional 5w30/10w30. A heavy duty engine oil like Rotella certainly wouldn't hurt anything, but I don't really see a benefit on a stock engine.
I run Valvoline Maxlife synthetic 5w30 in my 98 TJ 4.0L, it seems to be one of the quietest oils I've run in it. A friend also has a '97 ZJ Grand Cherokee 4.0L that has over 300k miles on plain old Valvoline conventional 5w30/10w30. A heavy duty engine oil like Rotella certainly wouldn't hurt anything, but I don't really see a benefit on a stock engine.
As you probably already know the 4.0’s are great engines!! Even with conventional oil these go 300k plus miles. Chevron Supreme is what we ran back in the day. Any full syn will be more than fine.
That 4liter is probably happy with any oil. It’s a very archaic design, would probably use any synthetic 5W-40
BrendanC
$100 site donor 2024
M1 0w-40, Valvoline EP HM 5w-30 or if you want to try to run an extended OCI after break-in; HPL PCEO 5w-40.
WOW!!! What support and input. I'm impressed. Here's where my mind/experience takes me. Back in 79-80 I was working at a Pontiac/Honda/MG/Jaguar dealership using petroleum based Pennzoil until the new craze of synthetics came out. The management decided to change to the new oil mainly to comply to the gas mileage crunch. After a while, in some instances days, mostly months of starting the change overs we noticed and uptake of Honda's coming in owners complaining of excessive blue smoke from tailpipes. The mechanics starting tearing the motors apart not knowing what to expect only to find nothing wrong inside. We sent oil out to be tested only to find out it was a synthetic base rather than petroleum base. Ok knew that but it satisficed the owners that we were doing something. We tried something on our own, w/o letting management in on it, we went and got some petroleum based Pennz put it into a Honda that just drove it smoking w/o doing anything else and the smoking stopped. What we figured was the synthetic was to slick and wasn't allowing the rings to seal allowing oil to slip by and end up in the combustion chambers. So that leads me to where I'm at today not fully trusting the synthetics. Am I just to afraid to step into the 2000's technology and it's benefits(?) or just unwilling to let go of what's been tried and true a good quality petroleum based oil? Is there still a good quality petroleum based oil available? Thanks again.
BrendanC
$100 site donor 2024
with a new motor, none of that is a concern. modern synthetics can be used in just about everything now a days.
You keep trying with the “Pennzoil ruined my engine” but there’s no basis for that in fact. Synthetics aren’t “too slick”, neither back then nor now. Your fears are unfounded.
You said you wanted the best and that would be a good modern synthetic. You also have to understand that most of today’s synthetics are chemically and structurally similar to any oil produced in the past 50 years. All oils are “petroleum based” and if you want a decent oil with superior properties then you don’t want the inferior oils that you’re mentioning.
Are you saying you have a 7 year warranty on this motor?
Yes 7 year/100k
Give it a good breakin and then a 4.0L won't care
What was then considered synthetic was comprised of a mostly PAO (aka Group 4) base oil and there was a learning curve with regards to how PAO would harden seals and needed to be balanced with an ester (aka Group 5) to counter this hardening. Hardened valve stem seals could allow for oil burning. So perhaps back in the late 1970's there was some poor quality control in the oils blended. There are people on this board who (@TomYoung , @MolaKule ) who know a lot more about what was going on back then than I ever will.
Today "synthetic" is rather a marketing term and seal hardening is no longer an issue. The 4.0l was a great engine. Drove one myself for many years.
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