Jabo

I just replaced the cam in my xj and when I read the warranty paper it said to use diesel oil in it to keep from voiding the warranty.I use lucus in mine with every oil change

RenoXJ

use it. but the only good its doing is giving you the warm*n*fuzzys

SeriousOffroad

Think again and do your research before making blanket statements that cannot be supported.
Read these...
http://www.ericpetersautos.com/home/...0&Itemid=10926

http://www.hotrod.com/techarticles/e...l_summary.html

http://www.joegibbsracingoil.com/tra...er/082106.html

http://www.joegibbsracingoil.com/tra...er/031606.html

http://www.ttalk.info/Zddp.htm

COSXJFAN

So Frank, this includes all "light duty" oils currently available, even "dino" lube??

whowey

ANY Gasoline oil that meets the API-SM specification has less than 1000ppm of Phosphorous. It's the main difference between the older API-SL and the SM specifications. Flat tappet camshafts need a level higher than 1000ppm to keep them well protected.


The oil that FrankZ was talking about (Chevron Delo) is a diesel oil. Diesel oils use a different rating system that creates some confusion on how they meet the SM rating while having a higher than allowed phosphorous level. Diesel oils that claim SM spec, won't carry the API certification mark(the so-called doughnot).

Lucas stabilizer really is nothing more than a viscosity improver and shear stabilizer. It makes your oil thicker and slows down the break-down process on the oil.


Valvoline dino does have Zinc and Phosphorous. If it is carrying the API-SM mark, just not enough of them.

whowey

Some cam manufacturers recommend diesel oils because of their much higher limits of Zinc and Phosphorous available on any shelf to people that don't pay attention to what they are buying.

A CJ-4 rated diesel oil allows 1200ppm of Phosphorous
A SM rated gasoline oil allows 800ppm of Phosphorous

SeriousOffroad

To the best of my knowledge, yes. I thought I had a web-based sreadsheet bookmarked that showed all of the major brands and their ZDDP levels but I can't find it. I'll keep looking for it.

COSXJFAN

I would've thought that there would've been some kinda notice to us "old" vehicle owners if they took a major friction fighting element out of lubricants??? Did I miss something??

Thanks for cluing me in guys!!

RenoXJ

They didnt "take it out" they just reduced it. In the name of fouling/plugging cats and being more "green".

HyPr0gLo

So where does that leave us newer guys? should we worry about adding the extra ZDDP to the engine if we have a mid 80's and newer XJ?

Right now I use Mobile 1 high millage and that has a ppm level of 1000 which seems to be less than the minimum needed (They have a chart with all of thier oils .. Click)

Should I also add some of the lucas oil TB Zinc+ or the ZDDP that blue uses with each oil change?

BlueXJ

HyPrO if you add something to your oil you will not harm anything. If you don't you may get premature wear. You decide.

RenoXJ

Ill speak for myself and most the guys here... were not running triple valve springs or 9,000 RPM... so regular oil is fine. Its enough to Make me sleep well at night. These 4.0L are not too picky.

BlueXJ

You can NOT ignore the writeups Noob. You need to heed the warnings or you will be replacing your camshaft sooner than later. That is an expensive thing to learn from.

sandstone

I just started adding Comp Cams Engine Break In supplement to my Mobil 1 10w-30 during oil changes in my '96 and '99 Cherokees and my '84 Dodge RamCharger, all of which have flat tappets. I've read too many scary articles and testimonials to ignore the advice on declining zinc levels in oils. It does add about $7 to the cost of the oil change, though. Any of the other zinc products ought to be OK, too.

sandstone

I first heard of this in an issue of Mopar Enthusiast magazine last year and I've been hearing more and more scary stories and reading more and more scary testimonials ever since!

Here's reference to the article that alerted me to this last year: http://www.forwardlook.net/6265-archive/msg25985.html