5 quarts enter, 4 quarts leave

[MattLaurence]

I'm convinced my asymptomatic oil usage is hinting at deeper problems for this 3.6L manual trans JLUS wrangler with 74,000 miles on it. I've read several similar posts, but im still concerned.

I have owned it since new and done all of the oil changes. In the beginning, I changed oil religiously at 4,000 miles, and at that time 5 quarts in, roughly 5 quarts right back out. But over the last year I've been letting it ride longer, going by the oil change percentage on the dash, usually changing it when the meter reads 15% life left, which is upwards of 6,000~ 7,000 miles between changes.

Just like the title states, usually only about 4 quarts comes out. Dipstick reads halfway up the hatch markings right before I drain it.... no smoke in the exhaust, no leaks, underside of jeep is free from drips, etc.

It may just be the "new norm" and something to keep an eye on for me. Anyone have additional thoughts on this?

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[mwilk012]

this is normal.

 

[Qjoh5510]

Half way up the dipstick hash marks would indicate it has 4.5 quarts. Bottom of hash marks to top is 1 full quart. A half a quart loss at 7k mile OCI’s isn’t terrible, but still could be pointing towards a potential future issue.

 

[Fuel Fire Desire]

Yep, normal. Every car I’ve owned, every engine did this. 3 GM 3800’s, a 3.8 JK, a 5.7 Hemi, and my current 3.6 JL and JT. Check the oil often, and if there’s more than 0.5-1 quart lost between oil change intervals it might be a red flag.....but I wouldn’t worry about it unless you’re having to add oil in between changes, you get a dripping leak, or it starts smoking.

The last two GM 3800 engines I owned never drank more than 1 quart between changes, and I took them to 300,000 mi. Consumption stayed the same from when I bought them under 100,000 mi, until the end. I’ve yet to take a Chrysler power plant beyond 100,000 mi though.

 

[Jeepin' John]

The 3.6 in the jeep is mounted with a slope down to the rear, putting the pcv valve / pickup at a lower point on the back of the valve cover, which makes for a lot of oil flow through the pcv line. I'm sure the engineers have some reason for putting it there, but it sure makes for a lot of oil consumption

 

[Punknhed]

ill check when i do my next oil change, but, i think mine is the same as others mentioned. I drive mine pretty hard, unfortunately mostly on pavement. Take a look at ur coolant make sure its not changing colors. i know mine on my cobalt at 267k and still going has turned black and it definitely uses oil but again im extremely hard on it and always have been. Long as the oil isnt milky that rules out head gaskets.

 

[JJMalone]

All four stroke poppet valve engines have to burn a little oil. Valve guides need a little, not much but any oil lubricating valve guides is burned. Oil to the intake guide is pulled into the cylinder and burned. Oil to the exhaust guides exit into the outgoing exhaust and lost. Also it is necessary for a slight oil film to lubricate pistons. Some small amount of oil is lost in cyl lubrication. Any of these engines that do not consume a small amount of oil in this fashion won’t last long. Suggest checking oil often and keep topped up. Running with the oil topped off will give you the best long term result. A 5 quart capacity motor running with 4 quarts is working the oil 20% harder and less oil to dilute contaminates.

 

[One_off]

At least it's not a honda S2000. That thing drank a qt every 2000 miles. Honda said that was normal.

 

[JJMalone]

At least it's not a honda S2000. That thing drank a qt every 2000 miles. Honda said that was normal.

In my experience a good tight motor will consume way more oil when worked hard up in the meat of the power band then the usual light duty a car motor gets when being driven for economy . A motor turning 6000 rpm makes the oil rings work a lot harder and can't scrape the cyl walls as good as it would at say 2000 rpm so oil consumption goes way up. 'Course that's why the C6 z06 comes with 8 qt capacity and the Wrangler 392 takes 6.7 qts; a little safety factor. Race cars usually way more.

I've never driven an S2000 but I bet that is a fun car to take driving and work the motor hard, the attraction of an S2000? Was that car driven hard much?

 

[m3reno]

I had a Porsche944 Turbo S and that thing drank a quart of oil every 1000 miles when driven hard. At that time the dealership said it was normal

 

[WXman]

Half way up the dipstick hash marks would indicate it has 4.5 quarts. Bottom of hash marks to top is 1 full quart. A half a quart loss at 7k mile OCI’s isn’t terrible, but still could be pointing towards a potential future issue.

I've had good luck with the 3.6. They seem to do well. I agree.

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