Sinking Creek 4WD Association

Mr.WJ wrote:Heavier weight oil likely won't help consumption. Need to find out where it's being consumed. Under warranty still? Also just Googling the 3.8 Jeep Motor Oil Consumption brings up countless threads about the problem. Somewhere in there, probably a lead as to why and potentially how to fix.

The 3.8L is prone to oil consumption even when it is running 100%. Specs from Chrysler say that 1 quart every 750 - 1000 miles is normal for that motor especially after 50k. Those very same threads you are talking about typically suggest going up a weight in oil when you read them, thats how I decided to go up in weight. One of the common causes is a failed or failing PCV valve which I will be checking however its been known that after replacing this valve it only helps the problem, not fixes it. I've come to learn that the combination of the 3.8L's lack luster power and torque at low RPM and its two-stroke like oil consumption are some of the biggest reasons people hate it and that Chrysler went to the 3.6L in their newer wranglers. The US market for the JK is the only application Chrysler calls for the 5W20, everything else uses a heavier weight. Those threads and many others like them are full of testimonials and opinions which are mostly positive, my motor is out of warranty so I am not worried about voiding it, which I probably already have anyway. I'll let you know how it goes after another 1,000 miles.

Here are some of those threads:

http://www.jkowners.com/forum/jk-genera ... -3-8l.html
http://www.jk-forum.com/forums/stock-jk ... -a-217397/
http://www.fourwheeler.com/how-to/engin ... -problems/
http://www.wranglerforum.com/f202/where ... st28809698

I read up on it after I posted the above, probably should have been the other way around. But you definitely seem to be on the right track. Maybe a 5w-30?

Also saw that 2008's were notoriously bad. Is that your year?

Mr.WJ wrote:I read up on it after I posted the above, probably should have been the other way around. But you definitely seem to be on the right track. Maybe a 5w-30?

Also saw that 2008's were notoriously bad. Is that your year?

I have a 2007, which was very similar to the 08's. Once they figured out some of the JKs flaws they began changing them around then. My girlfriend has a 2016 and its incredible when I look around at all the differences. I would like to go to 10W30 but first I am going to try 5W30 because there are many times when I get in the Jeep from a cold start and have to be very hard on it to respond to the fire station, that happens anywhere from two to ten times a week so I don't want to stray too far away from the less viscous oil. I am also considering using an oil catch can similar to what you would see on a modified LS1 motor. My father owns a corvette company and he believes that if I install one it will help collect the oil saturated air coming out of my crank case before it goes back into my intake manifold to be reburned. Hopefully I will then be able to measure how much oil I'm losing and prevent the motor from collecting more carbon build up. If I go that route I'll be sea foaming the engine.

Yeah the first couple years of the JK weren't the greatest. It's tough buying the first of any new generation, there are going to be flaws to work out, with anything.

Ugh, that hurts just reading it... having to start a car cold and get on the gas heavy is about the most destructive thing.

Catch can is always a good idea, can't hurt. With you saying you you've got to go fast sometimes, 5w-30 or maybe a 0w-40.

Bunch of baloney...my 08 has had absolutely 0 problems since I've owned it

Did some small stuff over the last week. I had some surface rust on my transfer case and evap skids, so I took them off, grinned the rust off and bed lined them. While I had the transfer case skid off I drained the transfer case fluid and refilled it with SuperTech ATF+4. I went with that brand because all of that fluid is made so close to spec that it is often manufactured by the same company and simply rebranded... or at least thats how I understand it. I switched over to 5W30 oil, stuck with Mobil 1 Synthetic and a Mobil 1 filter. I used seafoam on the top of the engine while I was as it. I also relocated my 2 gallon ViaAir tank to the trunk, I used to have it under the stock bumper but it got displaced when I put on the ARB. I also still have a brand new set of seat covers, a front skid plate, and some hood brackets available for sale or trade.

Recently I have also replaced the PCV Valve and changed the air filter.

Replaced the spark plugs since this month marks 10 years (120 months) since the Jeep was built. I only have 53,000 mi but I read to replace them after either 100,000 mi or 102 months. I went with the standard Champion Double Platinum plugs, nothing fancy. I'm looking into why my MPG denies as time goes on when the batter is reconnected. For example, I reconnect the battery and it says 18 MPG and slowly declines to 11 or 12 MPG over the course of a month.