Engine related issues at 50,000 Miles
01-06-2011 | 08:54 AM
#21
JK Freak
Joined: May 2009
Posts: 548
Likes: 0
From: Englewood, CO
Yeah, check the placement of the rings on the pistons if you get a chance. Pistons have been discovered on these oil burners with the compression rings installed with all the gaps lined up (=BAD) and oil expander rings fitted upside down (=VERY BAD). In other words, blatant manufacturing faults occurring at the assembly stage of production that lead directly to oil burning and premature engine failure.
Where I am the most commonly used V6 (found in GM sedans here for 20 years) is the GM 3.8L V6, which is very similar in vintage and design (ie: single cam, pushrods, iron block/alloy heads, etc) and performance to the Chrysler 3.8L V6 used in the JK. These GM motors have a legendary record here for longevity and the ability to take abuse and keep running, with many at well over 200K miles without any issues and never even having had the heads off. I just find it hard to accept that a growing number of perfectly maintained, lightly-worked Chrysler 3.8L V6s fitted to JK Wranglers bite the dust at the magic 40K mile mark, all due to oil burning and eventual bearing failure, and Chrysler continues to bury it head in the sand and deny there is a problem; particularly since this same motor in its 3.3L/3.8L variants previously had a good record for reliability and longevity in its minivan applications.
Sure, I've spun a bearing in a motor and sent a rod flying out the side of the block before but it was an old carburetor 202ci GM I6 with 200K miles on it & I abused the thing for years skipping oil changes, towing huge boats thousands of miles on mountainous highways, and redlining the crap out of it in every gear. I just find it inconceivable that the motor in my JK, which I maintain perfectly, change the high-grade, full-synthetic oil and filter every 3000 miles, may suddenly fail in another 5 or 10K miles (I'm at 35K at the moment) when I would expect to be seeing well over 100K miles on it before doing any major repairs on it.
Mine doesn't consume any oil, however I noticed an ever-so-slight tappet tick on it the other day for the first time that persisted for about 7 or 8 seconds after cold start-up that now has me worried.
Where I am the most commonly used V6 (found in GM sedans here for 20 years) is the GM 3.8L V6, which is very similar in vintage and design (ie: single cam, pushrods, iron block/alloy heads, etc) and performance to the Chrysler 3.8L V6 used in the JK. These GM motors have a legendary record here for longevity and the ability to take abuse and keep running, with many at well over 200K miles without any issues and never even having had the heads off. I just find it hard to accept that a growing number of perfectly maintained, lightly-worked Chrysler 3.8L V6s fitted to JK Wranglers bite the dust at the magic 40K mile mark, all due to oil burning and eventual bearing failure, and Chrysler continues to bury it head in the sand and deny there is a problem; particularly since this same motor in its 3.3L/3.8L variants previously had a good record for reliability and longevity in its minivan applications.
Sure, I've spun a bearing in a motor and sent a rod flying out the side of the block before but it was an old carburetor 202ci GM I6 with 200K miles on it & I abused the thing for years skipping oil changes, towing huge boats thousands of miles on mountainous highways, and redlining the crap out of it in every gear. I just find it inconceivable that the motor in my JK, which I maintain perfectly, change the high-grade, full-synthetic oil and filter every 3000 miles, may suddenly fail in another 5 or 10K miles (I'm at 35K at the moment) when I would expect to be seeing well over 100K miles on it before doing any major repairs on it.
Mine doesn't consume any oil, however I noticed an ever-so-slight tappet tick on it the other day for the first time that persisted for about 7 or 8 seconds after cold start-up that now has me worried.
cause the last time I went in for the only change my coolant was really low but they have not said anything about low oil and I have not used anyone else to do my changes, owned the jeep since mile 4. I do have the same tick when I do a cold start as you do but it only happens in the winter and I live high in the mountains. Curious, are you still using the factory battery? Anyways, like I said I have had the jeep since mile 4 and I have always had the cold start tick. I figure if I put a block heater on it it would go away but I have yet to test that hypothesis.
01-06-2011 | 09:40 AM
#22
JK Newbie
Joined: Dec 2010
Posts: 14
Likes: 0
From: Kansas
46,000
Well mine didnt quite make it this long. I bought it about a month ago with 45,000 miles on it. Lasted about three weeks and to like 45,650 before I had dealer come pick it up from a horrible noise from motor and major power loss when I was cruising on the highway. This is after I drove jeep for a week saw no oil loss then changed oil for mobil 1 synthetic and wix filter. Come to find out lost all oil feed to the heads which meant all my valvetrain was in the oil pan but dealer could not tell me the cause of it.. Dealer stepped up and is replacing motor with a Jasper reman at no cost to me but beware there are bad motors out there people.
01-06-2011 | 11:27 AM
#23
JK Newbie
Joined: Jul 2010
Posts: 27
Likes: 0
From: Knoxville, TN
Hey guys keep in mind that these threads and all that you read about bad engines and crap Jeeps are really just a handful compared to the amount of great Jeeps and engines that are out there. People don't complain when everything is awesome and going great, however if the smallest thing happens then the first thing to do is tell someone else. Just a thought. 
01-06-2011 | 12:30 PM
#24
JK Freak
Joined: Aug 2010
Posts: 892
Likes: 0
From: Euless, TX
01-06-2011 | 04:25 PM
#25
Thread Starter
JK Newbie
Joined: Nov 2009
Posts: 39
Likes: 0
From: Philadelphia, PA
Originally Posted by 07jeepX
Hey guys keep in mind that these threads and all that you read about bad engines and crap Jeeps are really just a handful compared to the amount of great Jeeps and engines that are out there. People don't complain when everything is awesome and going great, however if the smallest thing happens then the first thing to do is tell someone else. Just a thought.
01-06-2011 | 07:10 PM
#26
JK Enthusiast
Joined: Dec 2010
Posts: 208
Likes: 0
From: N.E. Georgia
Hey guys keep in mind that these threads and all that you read about bad engines and crap Jeeps are really just a handful compared to the amount of great Jeeps and engines that are out there. People don't complain when everything is awesome and going great, however if the smallest thing happens then the first thing to do is tell someone else. Just a thought.
) but to me, that's ridiculous for an engine with anything under 125,000-150,000 miles! At any rate, mines taken 4 now in less than 1500 miles since last changed, and it's about ready to hold another one. She goes in Saturday for an oil consumption test at my expense, and probably everything else will be too, since it has 85,000 on it, but I'm definately going to take my findings from the dealer and TRY to make Chrysler feel sorry for me....
01-06-2011 | 08:33 PM
#27
JK Newbie
Joined: Oct 2010
Posts: 73
Likes: 0
From: Greenville, SC
Let's us know the outcome. I'm at 36K on an '07 and not having any significant consumption yet, but I'll definitely be keeping a close eye on it.
01-06-2011 | 10:11 PM
#29
JK Super Freak
Joined: Feb 2009
Posts: 1,488
Likes: 1
From: Sydney, Australia
Yep, Chrysler won't investigate oil burning in a motor unless its well over 1 quart per 1000 miles. Which means by their reasoning, with a 6 quart sump you'd be down to a quart or less by the next scheduled change & the oil pump would be sucking air, and this is normal?
01-07-2011 | 08:03 AM
#30
JK Freak
Joined: Dec 2010
Posts: 647
Likes: 0
From: Bath, Oh
Originally Posted by JKlad
Yep, Chrysler won't investigate oil burning in a motor unless its well over 1 quart per 1000 miles. Which means by their reasoning, with a 6 quart sump you'd be down to a quart or less by the next scheduled change & the oil pump would be sucking air, and this is normal?
As for Chrysler helping out... people with legal tender debt notes were screwed over, why would they help someone with whom they have no obligation? And we are talking about a problem that stems from three owners ago. Call Daimler and ask for help.