High zinc oil in a 4.0l?

[pjm8047]

Not an b body question but a mopar question. My brothers restoring a 4.0 xj and we were wondering if it would be ok to run high zinc oil in his 99 xj? What do u guys think?

 

[MIKESPOLARA]

If it has a flat tappet cam YES
If it has cat convertors NO

 

[33 IMP]

If it has a flat tappet cam YES
If it has cat convertors NO

Exactly!

 

[pjm8047]

If it has a flat tappet cam YES
If it has cat convertors NO

Yes it has cats. Im not sure if they put roller cams in them. Without the zinc will it hurt the cam/ lifters?

 

[pjm8047]

Yup flat tappets with converters
https://www.morris4x4center.com/lifters-53010574ab-m.html

 

[33 IMP]

Conundrum. It has cats, you shouldn't use zinc, it has flat tappets, you should use zinc.
Personally, I would be more worried about the cam than the cats. I'd run diesel oil. My opinion only.
Edit: cats are easier to change than redoing an engine overhaul cause a cam went flat.

 

[Stumper]

Cam doesn’t matter but you don’t want to run catalytic converters with high zinc Oils

 

[Photon440]

When that Jeep was new, the SAE oils were still classified as SH. (What's current, SP?) There were no zinc limits yet back then. I wouldn't worry about it any more than the factory did.

 

[RemCharger]

Lots of people get 4.0L conventional oil changes everyday. With whatever that shop had in the barrel. Never heard of common cam failures.

 

[Bighouse]

Those 4.0s run forever it would probably go 100k on WD-40 lol

 

[Don Frelier]

Royal Purple

 

[blue69runner]

I am a Rotella Man. Mobile one is my next choice. But like my dad said oil is oil when you're reading low on the dip stick and you're on the road. I carry extra oil in the trunk of my vehicle. That way I alway's have the oil I am running. Still ad a bottle of EZ zinc additive on every oil change. 4 Oz bottle.

 

[Dave6T4]

Once the cam and lifters have been broken in, and run well together, as in the case of OP 's engine, zinc additive should be less of an issue. Rotella does not have near the amount of protective additives it used to have. At least, here in Canada.

 

[MIKESPOLARA]

Do you have emission testing where you're located for this year car? If not then run zinc and don't worry about the cats. If you have emission testing then you'll probably get busted when the cats fail due to zinc oil

 

[MIKESPOLARA]

Once the cam and lifters have been broken in, and run well together, as in the case of OP 's engine, zinc additive should be less of an issue. Rotella does not have near the amount of protective additives it used to have. At least, here in Canada.

I agree except not true if they are rebuilding the engine with new cam/lifters etc. He says they're restoring it, so is that new rebuilt engine?

 

[Don Frelier]

If it's pre 1996 and he is in NY there is just a safety inspection so you can remove the catalytic converter(s)

 

[pjm8047]

Do you have emission testing where you're located for this year car? If not then run zinc and don't worry about the cats. If you have emission testing then you'll probably get busted when the cats fail due to zinc oil

Check engine light must be off and all monitors must pass in nys to pass inspection

 

[pjm8047]

If it's pre 1996 and he is in NY there is just a safety inspection so you can remove the catalytic converter(s)

Its a 99

 

[moparedtn]

Its a 99

Ah, no worries - just fetch an emulator and ditch the cat!
(Oops, did I just advise him to break the law up there in NY?)