I've done a bit of reading about the oil formulations on the market today and found out some interesting things relative to the 4.0 engine.

When the engine of its type was designed (flat lifters, or "tappets") the oil on the market had the additives that provided the proper lubricant needed to prevent hard metal-to-metal contact between the cam lobes and the flat surfaces of the lifters they contacted. One of these additives was Zink.

Zink is no longer in the oils produced today. It was eliminated when the newer engines with overhead cams came into production because they did/do not need it. It was also the victim of ecology insofar as removing the ash (soot = air pollution) that it created that fouled up catalytic converters. So, Zink had its day. But, that doesn't help the 4.0 engine. The petroleum based and the PTFE (synthetic) oils today boasting high-mileage protection are, in reality, addressing overhead cam modern high-mileage engines, not older flat tappet engines of high mileage. The so-called "high mileage" on the labeling is misleading.

The additive ZDDP (Zink) which is known as the additive in break-in grease for new engines in their first runs, is also available as an oil additive for the older flat tappet engines. STP and Rislone, two well known names in additives, produce the ZDDP in an oil additive product. Yes, they can still foul a catalytic converter (over time) but I'd much rather lose the converter than the alternative. The Rislone also boasts cleaning properties that slowly work to remove the gunk built up in older engines, versus quickly removing it causing clumps to separate from internal surfaces and clog oil passageways and galleries.

I bought some of the Rislone with the ZDDP additive today on my lunch break and added it to my oil in the parking lot of the Advance Auto store I bought it from. By the time I got back to work the lifter tap (tappet) noise that's been bugging me was all but a whisper of what it was before I added it. I change oil as a routine every 3000 miles. Can it last longer? Probably, but I have a routine and I'm regimented to it. I've been using Valvoline 10W-30 full synthetic high mileage oil.

One article I read, which addressed older flat tappet designs, suggested using Rotella T5 oil, which is formlated for diesel engines, in addition to the Rislone ZDDP additive.

I'm going to continue to read up on the benefits of additives and best oils for flat tappet engines. In the meantime I'll keep the Rislone ZDDP in normal use with each oil change.

 

Lots of good info here: https://www.cherokeeforum.com/f2/rot...essing-188168/

Also, and not to be a douche, but there's no "k" in zinc.

 

I just use 15w40 diesel oil it has more than twice the zinc in it than most gas engine oils.

 

Another oil thread.

Oh goody

Haha

 

Yeah but can you still say "Rotella" three times and have Mr. salad appear?

 

Contrary to popular belief, Valvoline Max Life High Mileage 10W-30 contains enough ZDDP to protect flat tappet cams as long as you used a higher zinc content break-in oil when the cam was new. Max Life is a 50/50 mix of "synthetic" and regular petroleum oils, and since most "synthetic" oils today are just super-refined petroleum oils anyway, it's a perfect fit.

Having said that, due to the low idle pressure in my XJ, I use Rotella T6 5W-40 in it with 5K changes. I use the Max Life in my WJ with the new engine.

The 4.0 likes to run on liquid dinosaurs anyway.

 

Mobile 1 high milage zddp 1500ppm.

Sources:
https://www.enginebuildermag.com/201...-cam-failures/

Ed Peters tech talk. His application was the t850 transmission but the content still contains his quote that only mobile was willing to disclose their zddp level.

 

This honestly made me laugh out loud. I miss Ross, haha

 

I was just about to mention that. Btw, now Mobil 1 High Mileage is 900 ppm.
https://www.mobil.com/lubricants/-/m...94A7396657AC09

Would like to see a good reference from the OP on the claim that synthetic oil is based on Teflon (PTFE).

 

I would just like to summon Salad himself to this conversation XD...

I really thought we were going to make it through the month without an oil thread, we had done so good for so long. We had a real scare when SociallyUnacceptable said that he uses whatever is on sale at walmart 10/14/2020 his first day back but no one flamed him and I thought Jesus had came again.

Today boys I want you all to know that when this thread is over with, what happens on the oil thread stays on the oil thread. Don't lose friends over what smelly liquid they put in their 25 year old motor. In the end what matters IS WHAT RADIATOR WE ALL USE MISHIMOTO FOR LIFE Bahahhahahah.

 

Before this thread goes out of control and gets locked, I will share the one thing I normally do.

Zinc does nothing until its at least 160°. So all you guys that only drive your Jeep a few miles at a time, high zinc content does nothing as your oil wont get that hot. Oil takes a whole lot longer to heat up than coolant.

Carry on...

 

It's not the zinc that quieted your lifter. It was the detergents and solvents in the Rislone that helped free up a sticky lifter.

 

Well, reading is fundamental. That's where I am right now. Never spent a lot of time chasing down the qualities and properties of the various oils and their additives until a few days ago. The PTFE additive is real, despite the knowledge base here and it's predisposed assumptions about what constitutes factual information. I just go with the information available and make no such assumptions about it. If it's marketed to the automotive industry as beneficial then I tend to trust but verify without the need to make blanket statements for or against something.

https://www.super-lube.com/engine-tr...-syncolon-ptfe

Regarding the high-mileage oil of today's blends, this article basically clears up the question about Zink content and elaborates about its benefits. It isn't the only thing in print available on the topic. It's just one that I read among others.

https://www.hyperlube.com/blog/engin...older-engines/

I really had no intentions of stirring up a cauldron of posturing about oil, which seems to be pretty childish at this point. It's just a thread about something I'm reading about in an attempt to learn what will be most beneficial to an engine I'd like to keep in good order for some time to come. I have not read this entire thread. I walked in on the bottom side to see what twist the topic took and am pretty disappointed in the sand box maturity it fostered...about freaking oil, nonetheless.

 

I hope your not referring to me... I was only trying to be funny, I know how quickly these oil threads can go sour. My apologizes if you feel like I hijacked your thread...

 

Seriously?