Air bubbles do not lubricate very well check this out:
http://www.bobistheoilguy.com/images/lucas/lucas.htm

With the cold start temperatures of Winter right around the corner, just use any brand name 5w-30. As far as the "slightest ticking noise" how many miles are on this motor? If it's got a lot of miles it's probably something as benign as a lifter tick. Don't sweat it and turn up the volume on the stereo to mask it if it really bothers you.

 

Really? Then you don't know the 4.0 and history of it very well. This has been confirmed by CALLING and talking to different oil manufacturers. They also sell zddp additive for push rod engines now . It was taken out for the sole purpose of emissions. Thinner oils mean higher mileage and lower emissions, it's not necessarily good for an engine.

A lot of jeepers run the zddp additive with 10-30.

http://www.naxja.org/forum/showthrea...highlight=zddp
http://www.naxja.org/forum/showthrea...highlight=zddp
http://www.naxja.org/forum/showthread.php?t=992751


I can find another dozen zddp threads from jeep forums to corvette forums if you want...

 

They recommend thin oils to meet federal emissions standards. Plenty of 4.0 run year round on 15w-40. Rotella is widely known as one of the best oils for the 4.0 unless you are calling everyone else that runs rotella an idiot also...

 

I would suggest that it might be the fuel injectors ticking.
You can hear them on my renix firing off.
Use a long extension as a stephescope and listen to the injectors then move to the valve cover and move down it till you hear it loudest.
I doubt it is anything to worry about if its that subtle.

 

It's got 200K on it. I agree with the air bubbles in oil...not cool. However, they were using synthetic oils and a heavier weight, not 10W30 non-synthetic. I have seen those gear things everywhere and the bubbling is concerning but I have never seen one done with regular, non-synthetic 10W30...so idk if the Lucas really does cause it to bubble up like that. I would hope if it does that they wouldn't still make it, lol. Good experiment though.

 

Yeah, I will do that...I was looking into upgrading the injectors anyway so this might make me do it sooner, lol

 

fellas keep in mind straight 6 with the lifters on top sometimes oil doesnt drain back or gets up there because of the position of the lifter different than a v motor I remember going for 60 mile country rides in my 92 and having it play a symphany in many cylinders and oil changed 3k go to 10w30 oil and over 100k consider vavoline maxlife Im using it now in my 2000xj it seems to like it

 

U obviously didn't read the link I posted, your statement about thin oils and federal emissions standards is clueless and the only one using the word idiot in this entire thread is u. Use all the ZDDP u want, post post all the threads u want about cams and lobes and the lack of ZDDP in modern oils, that's cool. The 4.0L only has 55-60 lbs closed spring pressure. That's a little more than the spring in a "click type" ball point pin.

 

The lifters aren't on top, they're on the side of the block down low and are pressure fed by the oil pump via an oil gallery just like most hydraulic v motors.

 

I agree! The 15-40w oil got pushed aside for emission purposes. The greenies are at fault. I run my 99' with 15-40w year round. I always have fantastic oil pressure and the oil looks great (for its age/use) when I change it out.

Everyone has their own alligance to a certain oil and/or brand. Pour whatever oil in it that you're comfortable with. I'm not sure about the rest of you, but I don't have sponsor stickers slapped all over my stock Cherokee.

Also, let's not forget folks that not everything you find online (links) is true. There is a lot of bias and flat-out trickery out there (not claiming the any particular link is such).

 

X2 i checked mine when i was hearing the same noises and behold its a lil plastic peace up on the firewall.. Like him can remember the name of it. But that piece sounds exactly how u describe the noise.. Faint ticking

 

I just realized that you usually post just to contradict everyone's opinion and usually get shot down pretty bad.... Never mind.

 

15W40 is still readily available. It's gone nowhere but out of favor with the auto mfgs. No one recommends it any more except maybe the big rig mfgs. The higher the oil pressure, the lower the horsepower to the wheels. Re-read the link I posted, Motor Oil 101. There will be a pop quiz afterward.

 

Did u also notice that I post a number of info links/facts to try to myth bust, debunk (there's that word again) false info that just continues to be perpetuated on the Internet? Guess not.

 

That was a good link and a nice experiment...it was however pretty biased and causes you to have to "guess" on a lot of things. Still, I just say use what you use in it and stick with it...any oil is better than no oil at all, lol.