LS3 consuming lots of oil

[Zachalanche]

Hi,
earlier today while driving, i noticed my oil pressure decreasing any time i decelerated. So, I checked my oil when I returned home and the dipstick was bone dry so I'm down probably around 2 qts of oil. I checked my catch can, and it had some oil but not a lot. I then pulled my intake tube and found oil pooled at the bottom of the throttle body, so I pulled the throttle body off, and found about a pint of oil sitting in the intake manifold. Recently I've also been chasing an issue with a P0507 code which is generally related to vacuum leak or fouled throttle body seems like this may be related.

has anyone had a similar issue? did I route my pcv wrong? it currently pulls air from the intake tube after the maf to the front of the passenger valve cover, then goes from the rear of the driver side valve cover (where the port has an orifice) to catch can to vacuum port right behind the throttle body.

More specifics about the engine:
418 stroker
455 miles since build
roughly 300 miles since oil change.

car doesn't seem down on power, occasionally i see some smoke right on startup. but otherwise none. I'm surprised I can consume so much oil without leaving a big cloudy trail behind me......but maybe that is coming once my mufflers fill up with oil.
198554198553

[Zachalanche]

I found my first clue. I thought the valve cover i had was the one with the orifice, after removing, and taking a closer look, that definitely doesn't appear to be the case. So i've been running with no pcv valve. Fingers crossed thats all this is.

[andrewb70]

I found my first clue. I thought the valve cover i had was the one with the orifice, after removing, and taking a closer look, that definitely doesn't appear to be the case. So i've been running with no pcv valve. Fingers crossed thats all this is.

I bet that's it. You were definitely down on power. Oil in the intake is pretty bad for many reasons.

Andrew

[Zachalanche]

Nice thing is I can fit my arm all the way in the intake to mop this mess up. The hard part is finding a 3/8 barbed in line pcv valve.

[CarlC]

These work pretty well. http://mewagner.com/?p=444

[Zachalanche]

These work pretty well. http://mewagner.com/?p=444

Wow, looks M/E Wagner has thought of everything as it relates to pcv. I was reading about their baffle recommendations, and I wonder if the current baffling i have is also part of the reason for my oil consumption. the flow area is pretty small.

198695

[carkrazy1987]

currently battling a similar issue on my tbss. after i built a 408 for it ive have been going thru about a quart of oil per 50 miles. its awful. so far i have swapped 3 different gm valve covers, (old pcv style built in, and 2 orifice style ones, update v/c that is supposed to fix pcv issue) no change. ive actually went and removed the pcv system from my truck, removed and drained the intake manifold, and drove it 30 min in all kinds of driving to burn any oil residue left over in the intake and runners. after that i let it idle for an 1hr just to make sure. right after i shut it off, i ripped the intake back off, and found pools of oil on top of the intake valve. so next up is to change the valve seals and see if it makes any difference. at this point i am at a loss if its not the seals. it just doesnt make any sense. everything is freshly rebuilt, new seals and all.

[Zachalanche]

currently battling a similar issue on my tbss. after i built a 408 for it ive have been going thru about a quart of oil per 50 miles. its awful. so far i have swapped 3 different gm valve covers, (old pcv style built in, and 2 orifice style ones, update v/c that is supposed to fix pcv issue) no change. ive actually went and removed the pcv system from my truck, removed and drained the intake manifold, and drove it 30 min in all kinds of driving to burn any oil residue left over in the intake and runners. after that i let it idle for an 1hr just to make sure. right after i shut it off, i ripped the intake back off, and found pools of oil on top of the intake valve. so next up is to change the valve seals and see if it makes any difference. at this point i am at a loss if its not the seals. it just doesnt make any sense. everything is freshly rebuilt, new seals and all.

Weird. Ive had old engines with so much blow by that i couldn't keep the dipstick in the tube, but those engines would still make it between oil changes withou losing a noticeable amount of oil. I feel like you and i would consume less oil if our pcv lines ran from the bottom of the oil pan up to the intake.

[carkrazy1987]

ive spoken to a couple machine shops, and a few educated co workers and they cant believe the oil im going thru. machine shop said there was no way i was going thru oil like that thru the valves. they said it was rings. i dont know. its one of those hard to diagnose, because you cant really take it it too far apart easily. ive tried it all, including an expensive catch can. i believe ive tried all the "easy" external fixes. now all i can do is valve seals and pray thats it, after that, the engine comes back out, ugh. i am getting good at engine r&r on the tbss tho.

[Zachalanche]

Before my mustang became a pro-touring project, it had a 351w that i ended up breaking the ring lands off the #8 piston (in my younger and dumber years). I drove it for a while like that (1000-2000 miles) and it didn't seem like it drank oil like our ls engins, but that was 17 years ago and i probably wasn't keeping an eye on the oil level knowing the engine would be coming out soon. But it sure would smoke.

Have you tried a leak down test? I also think it would be hard to pass that much oil through valve seals. I recently had to replace valve seals on my motorcycle, and the oil loss was minimal.

[carkrazy1987]

i find it hard to believe too. i will do a compression and leak down when i do the valve seals. spark plug r&r is almost harder then pulling the engine.

i know i did just about like you when i got my ls together, i put about 300mi on it and started to feel loss of power before i notice the low oil pressure at a light. i was so low on oil, it couldnt keep the lifters pumped up. its weird thing to see, and the few other case i have found like this were all stroker ls also, but non ever showed resolved. im just waiting to replace my air compressor so i can do my valve seals, until then my truck stays parked for now.

[Zachalanche]

Do you still get oil pooling in your intake, or just on your valves?

[Zachalanche]

Heres where im at. Intake and spark plugs are cleaned up, and i added a pcv valve betweenthe catch can and the intake. Its what i had lying around so i did the free solution first. I also made sure to mount the pcv valve vertically. If this doesn't help, ill get more seroius about the m/e wagner pcv valve.
198724

[carkrazy1987]

since the last effort of removing the intake and checking the valves, i havent checked to see if its pooling again. i havent been driving the truck much either, trans let go during my diag lol, just bad luck all around.

[Zachalanche]

since the last effort of removing the intake and checking the valves, i havent checked to see if its pooling again. i havent been driving the truck much either, trans let go during my diag lol, just bad luck all around.

I would think that oil wouldn't travel from the valve seals to the intake (maybe someone will correct me here). if you find it further up stream is probably pcv related. if it is only on the valves then maybe it is valve seals.

[Zachalanche]

I just drove 25 miles and checked everything. No noticeable loss of oil. Just a small amount of oil in the catch can - maybe a tsp. no oil on the throttle body, but some residue in the intake (could have been from before). and the hose between the pcv valve and the intake was bone dry. Also the check engine light went away during the drive, which I expected with a clean intake and throttle body. Guess I'll just keep an eye on things for a while, but hopefully all it needed was a PVC valve......from a ford :naughty:

[icemanrd19]

Drivers valve cover is capped, passnager valve cover goes to the intake, valley cover to catch can and catch can to intake after the throttle body

[hp jnkey]

What brand of oil have you been using in the LS3 ?

I tried using Royal Purple in my C6 LS3 years ago and it was using a quart every 1000-1500 miles

Switched back to Mobil 1 , never used any oil again.

[Zachalanche]

Amsoil 5w30....but now some cheap synthetic from walmart until i have confidence that it wont be going out the tail pipe.

[Zachalanche]

Drivers valve cover is capped, passnager valve cover goes to the intake, valley cover to catch can and catch can to intake after the throttle body

My engine does not have a valley cover vent. So im drawing fesh air in throught the passenger valve cover and dirty air from the driver valve cover

[130fe]

Drivers valve cover is capped, passnager valve cover goes to the intake, valley cover to catch can and catch can to intake after the throttle body

That is how my Camaro and my LS2 based GTO are routed also. No issues.

[carkrazy1987]

i had royal purple break in oil, when first discovered my issue, then after the machine shop advised me to try and wash the cylinders, hopeing maybe the rings are dirty for some odd reason, i went with driven br oil. and then rotela just to keep oil in the car. i have mighty mouse catch can, uses oil fill on pass side for dirty >catch can> intake vacuum. and driver side valve cover to intake tube for clean air. i have been fighting my issue since january, trying to work on it between work, it was my dd, till the trans gave up.

[Zachalanche]

A little more than 100 miles since my cheap fix, and so far no noticeable loss of oil, and no increase in the oil in the catch can. So far so good, but the exhaust still smells like oil. I guess it may take some time burn the oil out of the mufflers or wherever else its hiding.

[pannetron]

+1 on that Wegner adjustable PCV valve.

[DualQuadDave]

If you are getting oil like that in the intake, the PCV isn't your problem. The lack of engine knowledge on this board anymore is sad, at best. A few things may have happened, that all lead to the same thing. Did you have the car tuned? Did the Tuner know what they were doing? Car smell rich when running? What the "wash your cylinders" comment you mis-interpreted was meant to be read as you "ran the car too rich and washed your cylinders with fuel, which ruined the ring seal". That is probably what happened. Mind you, may have been a machining fubar, the only way to know that is pull the motor and tear it down and measure. Where did you get the motor from? Any warranty? These days, good luck with that. Expect to pull the motor and have it done again. If you do, do NOT go back to the same place. I do have a few places I can recommend that do good work, but it's a short, expensive list. Wish you luck, hope I'm wrong.

[Zachalanche]

If you are getting oil like that in the intake, the PCV isn't your problem. The lack of engine knowledge on this board anymore is sad, at best. A few things may have happened, that all lead to the same thing. Did you have the car tuned? Did the Tuner know what they were doing? Car smell rich when running? What the "wash your cylinders" comment you mis-interpreted was meant to be read as you "ran the car too rich and washed your cylinders with fuel, which ruined the ring seal". That is probably what happened. Mind you, may have been a machining fubar, the only way to know that is pull the motor and tear it down and measure. Where did you get the motor from? Any warranty? These days, good luck with that. Expect to pull the motor and have it done again. If you do, do NOT go back to the same place. I do have a few places I can recommend that do good work, but it's a short, expensive list. Wish you luck, hope I'm wrong.

Thanks for weighing in.
I also hope you are wrong. I've since driven the car 1000 miles without losing a drop of oil, no oil present in the intake, and only trace amounts of oil in the catch can. So the PCV valve (or lack thereof originally), seemed to be the issue.

[dhutton]

Thanks for weighing in.
I also hope you are wrong. I've since driven the car 1000 miles without losing a drop of oil, no oil present in the intake, and only trace amounts of oil in the catch can. So the PCV valve (or lack thereof originally), seemed to be the issue.
Awesome!

[Steve68]

Know exactly what you guys are going through, built a SBC cam heads intake combo, got it running, drove it couple thousand miles and it was always smoking, oil coming out of the valve cover gaskets, just a mess, changed the valve covers, went back to a factory GM PVC system, all the parts, cleaned up the motor, 100% difference no smoke, no puking oil ever where, turned out to be a great motor, never even used oil between changes,

good you cleaned it up and went back to the vent and can,

[carkrazy1987]

If you are getting oil like that in the intake, the PCV isn't your problem. The lack of engine knowledge on this board anymore is sad, at best. A few things may have happened, that all lead to the same thing. Did you have the car tuned? Did the Tuner know what they were doing? Car smell rich when running? What the "wash your cylinders" comment you mis-interpreted was meant to be read as you "ran the car too rich and washed your cylinders with fuel, which ruined the ring seal". That is probably what happened. Mind you, may have been a machining fubar, the only way to know that is pull the motor and tear it down and measure. Where did you get the motor from? Any warranty? These days, good luck with that. Expect to pull the motor and have it done again. If you do, do NOT go back to the same place. I do have a few places I can recommend that do good work, but it's a short, expensive list. Wish you luck, hope I'm wrong.

never claimed to know it all, and still learn new things everyday. car was tuned from the get go, and and never ran rich, car ran for about an hour after build with spot on afr. so i didnt wash the cylinders down with fuel, not allowing the seals to set. may have been oil choice that gave me issues. checking and double checking pcv was the quickest and easier thing to check first before tear down. and when the machine shop told me to try and wash the cylinders, they ment exactly that, it was a last ditch effort, they though maybe the rings were stuck. getting that amount of oil in the intake can only get there thru the pcv system, hence why i looked there first. the engine does have to come apart, but all other options were trying to be checked first. id hate to pull and tear an engine down, just to find out it was a bad pcv system, or improperly setup pcv system. but maybe your right, i just lack knowledge, ill stick to my legos.