Tell me why I shouldn't change my oil

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Jeep 4.0L. Running Peak SAE30 with 1/2 bottle of SLOB. Wix filter. 2100 miles on oil and filter. 90% of my driving has been in temps 100+. Coolant 230ish is common. Change or run it longer?
 
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5K minimum in that engine in those conditions IMO! 4.0's will run on virtually anything that resembles an oil, so you are good to go!
 
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SO it's hot, that is not really an issue, what kind of duty cycle? If you are using it only on the road and getting it to those temperatures everytime you run it you can safely go longer. If you have been in 4 lo for a larger portion of those miles or you have mixed in a bunch of really short trips you may shorten it.
 
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Why such high coolant temps?? i can tow 4 ton in 90 deg and keep 200-210 all day, i think your fine it's a strait weight and with the slob adding zinc to the mix your good,take it to at least 5,000 or 6. On the other hand i would feel better tho with a synthetic in your temps your seeing.
 

Chris142

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 Originally Posted By: daman
Why such high coolant temps??
It's a Jeep. Pretty small cooling system in these. 10qts total capacity. It has been 110-120 for the last 2 weeks. Pulling a hill with the AC on with the fan clutch roaring and it will run right on 230 which is normal for the 4.0L.
 
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Newbie question. What the heck is SLOB? When in doubt, change it out. It cost me about $15 to change oil and takes me 15 minutes, plus it's fun. I'd just change it.
 

Chris142

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 Originally Posted By: GOPHER FREAK
Newbie question. What the heck is SLOB?
Street Legal Oil Boost An additive we like. It has Zddp and other stuff to help protect my non roller cam and lifters.Hard to find now
 
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Leave it for a minimum 5-6k miles. A straight-30 weight is already a pretty stout oil that can take heat better than a multi-visc., and you've further fortified it with a nice, strong additive - SLOB is loaded with goodies. And i practice what I preach - I run palin conventional out to 8-9k miles in my Cavalier in all weather/driving conditions. UOA's come back fine.
 
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 Originally Posted By: Chris142
 Originally Posted By: GOPHER FREAK
Newbie question. What the heck is SLOB?
Street Legal Oil Boost An additive we like. It has Zddp and other stuff to help protect my non roller cam and lifters.Hard to find now
WE like? Depends on who WE is. Dunno WHY you aren't running 5W30 as specc'd by the manufacturer? Then you wouldn't need the SLOB (you don't need SLOB anyway even with the straight 30). All that unneeded zinc and whatnot, bad for the CAT. Just run what they tell you. What, you know better than the manufacturer? Oh, I know. Cause you know BETTER. Sorry. My bad.
 
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Most temperature gauges use a a low pass filter so you do not really see what is happening to your coolant temperatures. When it does get too high you will then see the needle go to the red. You really don't think your coolant could stay constant through all types of driving do you? Mostly they work like idiot lights these days.
 

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 Originally Posted By: Oldwolf
Most temperature gauges use a a low pass filter so you do not really see what is happening to your coolant temperatures. When it does get too high you will then see the needle go to the red. You really don't think your coolant could stay constant through all types of driving do you? Mostly they work like idiot lights these days.
My Autometer gauge in the Mustang stays within a 10-degree range; 180-190 degrees. The fan comes on at 190, which then pulls it back down to 180. I agree that many of the modern gauges are very vague.
 
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I have a Scan gauge and a temperature gauge on my console. The Scan gauge will go from 188oF to 212oF and the console gauge stays the same. Idiot light I would agree! ;\)
 

Chris142

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 Originally Posted By: toocrazy2yoo
Dunno WHY you aren't running 5W30 as specc'd by the manufacturer?
Jeep calls for 10w-30 And they show less wear with 10w-40 and 15w-40. I'm running ZDDP because flat cams are beginning to show up on the Jeep boards now. I never saw a thread about a stock cam going flat before SM oil. I don't want my cam to go flat. Too much work to fix it.
 
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I read just the opposite on one of the Jeep boards. They had several members post the best UOA's with 10W30, vs the 40wt and 50wt oils in their 4.0L engines.
 
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