Engine oil?

[pezter65]

What type of engine oil do most people recommend for a 4.0? I live in Southern California,San Diego ....

[nickyg]

I use 10w40 Of whatever big name brand that's on sale. I think the key to oil is to make sure you change it on a regular basis.

[cpttuna]

I also use what brand name I can get on sale. I also use a quality filter. I won't mention any particular name. I do not want to start any arguments. I like what I use and I like the price I have to pay for it. To each his or her own.

[Mudderoy]

I ran Pennzoil straight 30 weight for about 125k miles. Due to some recent "events" we've swapped out the completely rebuilt 4.0l and put the original engine back in. This is the same one that I ran the Pennzoil in. The engine looked great. We honed the cylinders, new rings, replaced the rod bearings, and had the head redone.

I have Pennzoil 10w30 in it now, that's what I had on hand. When the 500 miles are up I'll be switching to Mobile 1 high mileage synthetic.

[downsy]

Usually standard Dino Rotella T here with a NAPA/WIX filter.

[98XJblack]

I had to replace my camshaft after a whole series of events including a blown head gasket and cracked head in my 2000 XJ. The camshaft and lifters were showing serious wear including one in particular that was completely gone. From a reputable and knowledgeable machine shop that does engine work informed me that the 4.0 because it is a flat tappet engine (no rolling lifters), truly needs oil with a zinc additive to keep those crucial engine parts lubricated. Conventional motor oil and most any oil for consumer on road vehicle had the zinc removed from them to meet federal emissions regulations. I suggest getting that additive for your oil changes or find a place that sells off-road/racing oil (this is how they get around the zinc issue by saying it's not for street use. Look into it, could save your engine from a disaster like mine.


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[pezter65]

Thanks for the information 98 I will look into that!

[denverd1]

you can also buy the zinc additive separately and add it to whatever oil you're using. HAS to be cheaper than "racing oil"

[denverd1]

hmmm.... that begs the question, why not put roller lifters/rockers into the 4.0? MORE POWER!!!

also wondering about longer than stock roller rockers that give more valve lift than the standard rocker ... ? might be a great way to wake up a 4.0 sans cam job :rolleye0012: :cheerleader:

Sorry guys! got a little excited there.

back to your oil discussion, I run penzoil 10w30. haven't had a reason to change. high mileage means high dollar. ain't fer me!!

[pezter65]

Does anyone know who makes the additive is that something from Lucas or what?

[downsy]

Diesel oils have higher levels of ZDDP (anti-wear additives) than gasoline oils. Examples of Diesel engine oils are.

Rotella
Delo
Mobil Delvac ect.

[pezter65]

😆 thx

[denverd1]

not sure about lucas. it's common in the racing world. find a good speed shop, they'll be able to point you in the right direction.
or this: http://www.nthcoast.com/product.asp?itemid=769&gclid=CjwKEAiA4rujBRDD7IG_wOPytXkSJACTMkga8iLSwBwZ pvYtes2lgt4oWOulu0-O60W8LdozaXk40hoCJurw_wcB

[4.3LXJ]

I use Valvoline racing oil. Highest additives on the market

[abebehrmann]

hmmm.... that begs the question, why not put roller lifters/rockers into the 4.0? MORE POWER!!!

also wondering about longer than stock roller rockers that give more valve lift than the standard rocker ... ? might be a great way to wake up a 4.0 sans cam job :rolleye0012: :cheerleader:


Someone please correct me if I'm wrong but I think if you replace your stock lifters/rockers with rollers, you also need to change out your cam as it needs to be ground specifically for the rollers. Something about how it contacts the cam lobe differently. Read about it in Eric Zappe's new book.

Jeep Cherokee XJ 1984-2001: Advanced Performance Modifications (Performance How-To): Eric Zappe: 9781613250792: Amazon.com: Books@@AMEPARAM@@http://ecx.images-amazon.com/images/I/61DGlNb%2BJIL.@@AMEPARAM@@61DGlNb%2BJIL

I use Mobil 1 High Mileage Synthetic 10w30 because it has one of the highest ZDDP contents I could find in a full synthetic and you can get a 5qt jug for about $20 at Walmart. I do my best to not shop at Walmart but I do go there for engine oil as it's usually around $10-15 cheaper than the parts store.

[4.3LXJ]

Correct on the cam and lifters

[Pookapotamus]

I would like to start this thread up again, I am going to rebuild my ax-15 here very soon and use redline synthetic for it, so I figured I would look in to Redline racing oils for the engine as well, does any one use this or have experience with full synthetic in a 4.0L?

http://www.summitracing.com/int/parts/red-10505/overview/

[4.3LXJ]

No experience with engine oil, but I run full synthetic high temp oil in the 4L60E tranny. Great stuff. It is designed for motor home use, so it will take some abuse

[WhiteDevil1311]

Rotella 15w40 365 days a year and it lives in chicago.

[prcjeep]

Rotella 15w40 365 days a year and it lives in chicago.

I put this in just before my my trip to Big Bend, lots of exteneded idling, full tank runs etc. I'm planning on changing it soon and sending a sample to blackstone labs for analysis, The oil has about 3000 miles on it.

[abebehrmann]

I put this in just before my my trip to Big Bend, lots of exteneded idling, full tank runs etc. I'm planning on changing it soon and sending a sample to blackstone labs for analysis, The oil has about 3000 miles on it.

I hope you do, would love to see what the analysis says.

[Pookapotamus]

I have been using rotella too, but I have had to rebuild morts engine twice, don't really think that had anything to do with it, but figured I would look into motor oils and see what I come up with

[WhiteDevil1311]

Prc. Go for it. I use it for the benefit of the tappets. I havnt hit 3k since last years fathers day weekend when i last changed it. Still looks new and smells like the gallon jug of it does.