Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (
-   Troubleshooting/Problems (
-   -   5.7 drinking oil :/ (

remmy 06-28-2013 08:17 AM

5.7 drinking oil :/
Ive got a 107,XXX mileage WK but the motor was rebuilt and has almost 50k on it. It has an intake/headers/exhaust and a mild tune with EGR blocked off. I also dont really beat on it.

This thing is eating 3-4 quarts of oil between changes and I notice once in awhile a small puff of blue smoke out the back when accelerating from a stop.

Ive had cars where the motor was going bad and they always showed signs or sounds of distress but this one runs and sounds like it does as always. I dont even have a "HEMI Tick". My driveway has no stains either.

Could it be a bad PCV possibly? Ive heard of them causing the loss of 1 quart every 500 miles in some cases.

dr.lee.baugh 06-28-2013 10:38 AM

Re: 5.7 drinking oil :/
I would certainly check the PCV valve as a start.

Just remove it and give it a shake. If it rattles, it is likely ok. They are also cheap to replace, so you can always swap it out as preventative and see if that solves the issue.

dmsfun 06-28-2013 11:01 AM

Re: 5.7 drinking oil :/
A bad PCV creates excess pressure in the crankcase which can blow seals, then causing oil consumption. Replacing the PCV now though will be too late, if that is the cause of the problem since that much oil loss is huge. I've never had to even top off mine between oil changes of 7500 miles. Question, why was the 5.7 rebuilt with such low mileage on it ?

remmy 06-28-2013 11:30 AM

Re: 5.7 drinking oil :/

Originally Posted by dmsfun (Post 849777)
Question, why was the 5.7 rebuilt with such low mileage on it ?

Dumb ass brother hydrolocked it in d/t Charleston, SC while I was on deployment in 2010.

remmy 06-28-2013 11:33 AM

Re: 5.7 drinking oil :/
Ill have to order a PCV, NO ONE effing has one in town. WHY?! the 5.7 is practically in every chryco ever made this side of the millenia.

Ill have a compression test done later as well. If anything I hope I can get by with it for at least another 6 months and baby it. Im not throwing any more god damn money into this thing. Its nailed me $10k in misc b/s repairs in the last year and a half... well, some major but still.

dr.lee.baugh 06-28-2013 05:52 PM

Re: 5.7 drinking oil :/
While I agree with dmsfun that a stuck PCV valve could eventually cause motor damage, I don't think the amount of oil you are burning through necessarily indicates your seals are blown. In my experience, when a PCV valve is stuck wide open like that you'll also have issues at idle (which you do not report).

I think a couple of quarts in a few thousand miles could be just the valve staying open itself.

remmy 07-01-2013 09:59 AM

Re: 5.7 drinking oil :/
In fact, it does stall once in every couple of weeks at idle. Havent checked it yet. I forogt this weekend to do it.

remmy 07-10-2013 09:26 AM

I'll be ordering a new PCV on Friday. I added a slightly different Mobil 1 called "Advanced Formula" ... Whatever that is. It was all they had. Haven't noticed much oil burning since.

Curious; could I theoretically add heavier weight oil if I disable MDS with my diablo sport tuner?

remmy 07-10-2013 09:32 AM

Re: 5.7 drinking oil :/
Eh, just talked to a friend about it. He mentioned that it wouldnt work as it would f*** up the hydrualic lifters and MDS has nothing to do with it. He also said "American lifters designed only to work with 5-30 is the dumbest f***ing thing ever."


remmy 07-22-2013 09:11 AM

Re: 5.7 drinking oil :/
I installed the new PCV this weekend. I had to use channel locks to twist it out of position to remove it. Fair warning; you might need some needle nose pliers. The head snapped off its shaft when I tried to pull it out :( . Fortunately I had a tall friend with freaky long skinny arms who had the positional fulcrum to somehow pull it out. I lubed the new one and popped it in easily.

I noticed the old one was really oily and had residue. Cant tell if it was jammed as it broke when pulling it out although the small piston seemed to move freely. Well see from here. Im just about out of options with this oil burning issues (burned through a quart in 4 weeks) other than switching to straight up dyno oil (non-synthetic)

Install tip: Make sure the little hole under the head of the top of the PCV faces the breathing tube that goes into the head of the motor once installed

jeepgcoman 07-22-2013 11:37 AM

Re: 5.7 drinking oil :/
A couple things. Why don't you have a catch can on that thing yet? That would for sure tell you if it's coming from the PCV System. You'd probably be emptying it every other day. Secondly, I install my valves just the opposite of what you're saying. The way you have yours installed provides a direct path from the valve hole, through the hose and into the intake. I install mine with the valve hole to the rear, away from the hose. This makes it a little more difficult for any oil to get around the corner and into the hose. Don't know if it makes a difference though. I've also looked in the FSM and it doesn't specify, so I guess they don't care, or it doesn't make any difference. Also, I've added a second in-line PCV Valve, between the stock one and the catch can, and it doesn't really seem to make much difference in the amount of stuff I get in the can. Just another experiment I tried to see if I could retard the amount of oil coming through the system.

remmy 07-22-2013 12:27 PM

Re: 5.7 drinking oil :/
Im assuming the reason I would need a catch can is because too much oil is getting by the PCV and dumping it into the intake? And Im also assuming the PCV on backwards prevents more oil from getting by? Just wondering, you dont think that might have any long term effects? Im not a mechanical expert.

All times are GMT -5. The time now is 03:54 PM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community