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

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.

dmsfun said:

Blue smoke = engine oil is leaking directly into the combustion chamber, and pcv blowthrough would not cause this. My guess is either valve stem seals or piston rings were not done /installed properly by the rebuilder. I'd confront the rebuilder about the problem.

Click to expand...

DUDE. I LOVE YOU. So glad you convinced me to check up on the warranty.

Jeep Since New: 108,927
Engine Repaired: 75,712
___________
Current Engine Miles: 33,215

Date Repaired: Oct 09 2010

Warranty (even if it was a short block repair): 3 Year/100k



Looks like Im still under warranty :thumbsup:

Waiting for the dealer to call back once he pulls my hard copies up.

I need to resurrect this thread. I bought a 2005 GC with a hemi. I got it fairly cheap cuz it had a knock that my mechanic thought was a rod bearing. Turns out it was a valve seat that had dropped and took out a piston. Took head to a machine shop and did just the seat that dropped and put in a new piston. Buttoned the engine up, started, ran, shut it down restarted BANG another valve seat dropped, another piston ruined. This time both heads go to machine shop, all intake valves seats replaced and another new piston. I'm into this engine almost 3 grand. It has 148,000 miles. Now my problem this thing drinks oil almost 2 gals. in 800miles. I put in a new PCV it still billows blue smoke. I unhooked the hose that goes from the PCV to the intake plenum and plugged the vacuum still blows blue smoke. I thought maybe the crankcase was being pressurized by blowby so I took the oil fill cap off and have been running it directly into the air. What do you think might be the issue?

Asssuming they put the new pistons/rings in correctly, it sounds like there may have been more damage to the engine than you (and your mechanic) initially thought. Dropped valve seats are caused by excessive heat, and in many cases the stock temperatures these things run at are too hot. The cooling fan doesn't come on "high" until about 235-240* with the stock thermostat and PCM fan "start" temperatures are all set too low, IMO. Unless you find something simple amiss, you'll be taking it apart again.

I have two Hemi's in the range of the potential dropped seat problem. I've been very proactive though, beginning with cooler (190*) thermostats and fan start temps. set to 198 for low, 203 for medium, and 207 for high. Neither of mine never get more than about 212* and then just momentarily until the fan cools it back down. I recently did a test at a road construction site. We sat there for a full half hour in 104* temps. with the A/C on and it never got above 208 while sitting there. Once we got going it briefly got up to 214* and then cooled back down under 200*. I've been running this setup on both for about 7-8 years without issue.

Also, since the valve seat issue was starting to show up more again I decided last year, since we travel a lot, to pull both apart and have ALL the seats replaced on both engines just for a little added insurance. While I was at it I had them ported/polished and milled .030 in. When the guy was cutting the seats out of the heads off our LX (the one we use most for travelling), he was able to only cut them half way before they started spinning in the heads. They were probably candidates for the dropped seats. Glad I had it done before we had a problem.....perhaps in the middle of no where.

Good luck and I hope you find something simple otherwise, if the rest of the vehicle is sound, I'd be saving for a stroker motor, as the cost isn't that much more than a new 5.7 short block. You'll already have the heads done.