15W40 Heaven!
12-23-2011, 09:40 AM
#11
JK Super Freak
I noticed a significent decrease in engine noise when switching to 5w-30. I'v sent off a sample of my used oil since switching, and every wear metal is within universal averages except for copper, which seems to be excessivly high in every UOA (used oil analysis) I have seen for the Wrangler 3.8, including those who use 5w-20. I imagine there are lots of people on this forum who would be very interested in seeing a UOA of your oil when you drain it. That will give us a hard answer to the question of using thicker oil. I usually go through Blackstone labs and they charge $25.
12-23-2011, 09:47 AM
#12
JK Enthusiast
Join Date: Nov 2011
Location: Ohio
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12-23-2011, 09:58 AM
#13
JK Freak
I don't let anyone do my oil changes ever free or not ill pay for it and do it myself. I have been running 10-w30 since I bought mine w/o problems. Got some friends to switch from the 5w-20 and they are a lot happier as well
12-23-2011, 05:16 PM
#14
JK Newbie
Join Date: Nov 2011
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funny, the 3.8L in the vw minivan (rebadged caravan) is 5w30 regular old castrol by vw specs. still have issues with them on occasion. have had them apart a few times. It is an old war horse engine. I think the factory is after any help they can get with MPG and emmisions. seams to me that it should be on 10w30, bearing clearance is not that tight when compared to engines that run on 5w20 or thinner. the 3.8 is actually kind of a "loose" engine.
12-23-2011, 06:11 PM
#16
JK Freak
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I use 5w-30 winter and 10w-30 summer. 42K miles and does not burn a drop of oil. Runs like a champ!! Despite all the negativity surrounding this motor, I actually like it and am hoping to get at least 150K out of it with proper maintenance. F*ck the pentastar 
12-23-2011, 06:25 PM
#17
JK Newbie
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Just did the same hung and what a difference to engine's sound. Has not been long enough to test the oil usage.
I wonder if re routing the pcv piping like the older cars would solve oils sucking issue.
I wonder if re routing the pcv piping like the older cars would solve oils sucking issue.
12-23-2011, 06:36 PM
#18
JK Jedi Master
There were many variations of pcv systems over the years. What do you have in mind?
12-23-2011, 06:47 PM
#19
JK Enthusiast
Join Date: Aug 2011
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I live in one of the hottest places in the US where it is always over 110 in the summer; over 115 much of the time. I run 5W-20 per the advise of the service centers here (Mobile 1 synthetic). I have 50K on the 3.8 and it does not use oil. I may go to 5W-30 but don't see a reason to right now. I am not sure that the bearings in this version of the engine are the same as those from 20 years ago when 10W-30 was the norm.
