I'm in MN and am running Mobil 1 10-30 now. It's not that cold this year either and it's been starting fine. As an aside, I've had my 2001 since august and am starting to slide to the side of "as long as you change it, the jeep is just not that picky on oil" side. I get more clattering with the Mobil 1 than I did with regular old walmart dino oil. Maybe I'll split the baby and throw in walmart duratech synthetic next time to see what happens, the price is about the same as conventional. I just don't like to change it so often.

 

If one is going to run synthetic oil, why run 10W30?.....Mobil 1 is available in 0W30 and will certainly flow quicker to the top than 10W30. Again, 0W30 and 10W30 are the same vis at normal operating temp.

 

I've often wondered though, would running 0w30 in an older engine that burns a little oil cause more burning when cold? Now if I'm wrong, please correct me, but with the oil being thinner and flowing easier, wouldn't that also mean it can sneak by valve stem seals and rings while the engine is cold as well?

With that question being asked, I settled with Rotella T6 5w40, and love the result in my 207k mile 4.0. I can def tell the 5w has less cold start noise than the 10w did, and also quieted down the engine when hot as well as reduced oil consumption slightly.

 

I'm sure in any "loose" motor a lighter oil will get past parts quicker than in a "tight" motor but at the same time the quicker oil gets to the top of a tight motor, the longer it will stay a tight motor. A little by the rings and stem seals just makes for good upper cyl lube. Mobil 1 makes a 0W40 oil, wish Rotella would come out with theirs soon.

 

30w is 30w...one is not lighter than the other. I've said it before, ill say it again...the only reason 10w30 is still sold, is because people buy it. Every vehicle that has a factory recommendation of 5 winter or 10 winter can run 0 winter ALL YEAR LONG. It's simple, it really only comes down to two things: brand preference and conventional vs synthetic (or semi-synthetic).

 

have coolant loss and ive been reading a lot about this, some say cam bearing, i dont think its a cracked head b/c the coolant level is the same in the resevoir its just at the bottom and its not running hot, infact its running quite well no knocks or ticks gonna get a mech oil pressure gauge but got the feeling it will read the same

should i start looking to have the cam bearings replaced or what

 

Kinda puzzled.....u say "have coolant loss" then u say "the coolant level is the same in the reservoir". If you're loosing coolant somewhere, the coolant level in the reservoir will drop, eventually being empty. This presumes the radiator cap is functioning correctly and u are not adding coolant. The coolant level in the reservoir should fluctuate upper/lower as the motor heats/cools. Look at the marks on the side of the bottle, the lower mark is minimum when the motor is cold. There must always be some coolant in the reservoir, if not, air enters the system.

Start with a reliable shop that will install a mechanical oil pressure test gauge and go from there. Also, the port where the gauge screws in needs to be clear and not plugged with crud (thanks cruiser).

 

its at the bottom of the resevoir which it where it was before i added coolant it went back there after a day of driving and it stays there, also can i replace the sending unit if the engines hot or will i get burnt

 

Is the level below the bottom mark on the side of the bottle motor COLD? For safety sake, don't do anything on a hot motor.

 

yes well below but there is coolant in the bottom

 

no coolant in the oil, coolant is about 1 1/2 to 2 inches below the add mark in the resevoir and the radiator is full of coolant, it doest run hot
any thoughts?

 

The zero weight oils do not hold up as well as a 10 or 5w. I forgot the exact details, but I know this to be true. You want the #s as close as possible, depending on ambient temps of course.

All I remember is something about the additive package and molecules stretching.

 

I do not want to be an idiot. You have 130,000 miles and say your oil pressure is a little low. Why not change the oil pump and fix the problem?

 

i switched to 10w 30 mobil 1 hm, a lot of what ive read on here says oil pumps wont fix the low pressure, its fine at cold start up about 50 psi then after its hot it idles anywhere from 10 to 20 psi, they say oil pumps create flow not pressure, its a 2000 so its an 0331 head which have problems, where im getting confused is what causes the head problems, i read an article that says the cam bearings go bad on these and the spacing is what causes low pressure when they are hot but would this cause coolant to leak into the oil, ive only filled the resevoir up once and lost all of what i added and im hesitant to add more, the reason i bought this is because my lumina was drinking coolant and it wasnt hitting the ground, im worried this has the same problem only diff is i havent seen coolant in the oil yet and the radiator is full

 

Why not just add coolant (motor cold) up to the minimum mark on the bottle? The next day and for several more days when the motor is cold, check to see if the coolant level in the bottle is holding steady at the minimum mark (motor cold).

"I forgot" this....."I know" that....."All I remember" is something.....and we wonder how oil myths are perpetuated over the Internet?????...C'mon man.

Why not have oil pressure verified 1st. Factory gauges/sending units are known crap.

The 0331 head has a weak casting flaw that can crack if overheated. The crack can allow coolant into the oil. If the oil becomes contaminated with coolant/water, the contaminated oil will not properly lubricate motor bearings causing bearing failure. Increased bearing clearances causes lower oil pressure. Cam bearings, crank main bearings, rod bearings, etc., can go bad on any motor if the oil becomes contaminated and looses it's lubricating ability.

Need to get your oil pressure checked/verified and go from there.

tj, cruiser, and others.......I need your help.