SpinsB

iTrader: (5)

Used up about a quart in just 280 miles. Mild driving on the street. I had a compression test done last october and all numbers came back good, rings in good condition. No oil leaks or anything of the sort. A little white smoke on start up but goes away. What to check? where am I eating oil at? Next step?

LS6427

iTrader: (2)

If there's no external leaks, and you know the rings are NOT the problem...the valve seals would be about the only way you can burn that much oil. PCV, a tiny bit.

SpinsB

iTrader: (5)

No external leaks at all. What would be a good valve seal to go with. Its an LS1 head ported and all that jazz. Any does and dont's when doing so??

good2go

My LS7 427 was eating a half quart every 2,000 miles through the PCV system. I'm now running a K&N breather with no vacuum to the crankcase and have ZERO oil usage.

MrDrezzUp

iTrader: (1)

I have a new 416 that is also chewing through large quantities of oil. I was freaked that it was the rings, but I have been told it is the PCV system and have since purchased a Cartek catch can. The Cartek catch can is unique in that the PCV system routes to the can and the can does not route back to the intake or to the throttlebody. Many catch cans route back to the intake and throttlebody. With the Cartek catch can there is no way oil can get into the intake.

I have not yet had a chance to test if the Cartek catch can has solved my problem, but I am hoping it will.

The PCV system on these engines is a fixed orifice. When GM decided on what size of fixed orifice to go with, they may have based their decision on how much vacuum was being produced on the intake side. With an aftermarket motor (especially something as large as a 427) the amount of vacuum has probably been significantly increased. Thus, the amount of suction on the PCV system would also increase, which would draw more oil mist into the intake. When I installed my catch can, I also removed the throttlebody to look inside of the intake. The inside of the intake was all oily yet the intake only has ~2000 miles on it.

Take a look at your spark plugs. If they are all oily (and oily the same amount) the PCV is probably the culprit as the chances of all of your valve seals being bad (and being bad the same amount) is a bit slim. If only a few are oily, or some spark plugs are a lot more oily than others, bum valve seals are probably the issue.

SpinsB

iTrader: (5)

the last time I changed plugs all the plugs had oil all over the threads. The spark end itself was clean of oil but was brown from the oil its burning? Should I start with a good catch can and see if I can get the car oilmist free see what happens then look into the seals??

MrDrezzUp

iTrader: (1)

Exactly.

My plugs were exactly the same. Spark end itself was reasonably clean but the threads were oily. I think it is like you said. The oil is burnt off of the spark plug tip.

If all of your plugs look the same it could be one of three issues.

1) Your heads were ported to such an extreme that the rocker bolt pathway actually pierces through. Oil is moving past the rocker bolts into the intake path. <-- Unlikely. To check this a rocker arm bolt is removed and a visual inspection is done to see if the bolt hole pierces through the head (it is not a blind hole anymore).

2) All of your valve seals have popped off of the valve guides. <-- Unlikely. To check this, remove the valve cover and take a look. If the valve seals have popped off they will be riding high on the valve stem. You can see this even with the valve spring still on.

3) PCV system is the culprit. <-- Likely. Install a catch can that eliminates the valley to the intake PCV, and the passenger side valve cover to the throttlebody PCV. Also install a oil cap breather. The majority of catch cans, still route back to the intake and throttle body. Look for one that does not.

SpinsB

iTrader: (5)

Here is where I get confused. I have no hose going from the vally to the intake. The tube coming from the vally is capped off.? Also Ever catch can I see still goes back to the intake. Who has them that dont? I did a search for cartek catch can with no results... Out of all three I hope its the PCV

MrDrezzUp

iTrader: (1)

Unfortunately, Cartek does not have the catch can on their website. They need to be called to order one.

If you already have the valley hose capped off that would leave the line from the passenger side valve cover that is running to just before the throttlebody.

As a temporary test (before running out and buying a catch can) you could do the following. Install an oil cap breather, and plug the PCV line running from the passenger side valve cover. Drive the car for a while and see if the oil consumption ceases. Make sure you have an oil cap breather as the crankcase needs a way to vent.

SpinsB

iTrader: (5)

I understand all of that. Where or who has a valve cover breather? Not looking for a cheap one that just replaces the oil fill cap. Ive seen ones that replace the whole neck and cap.?? WS6store has one but not sure if it is a direct replacement. any ideas.....

Gordon0652

iTrader: (4)

Thank you for the idea!
Couldn't you just drain it back into the oil pan?

SpinsB

iTrader: (5)

Did some more research and reading found a breather that will work for me. I will try the breather and cap off the pass. side and see what happens. There are now down sides to doing it this way is there? Will I still need a catch can? If I do the breather and cap off the pass side and the oil consumption seems to stop do I just keep the set up that way or what?

MrDrezzUp

iTrader: (1)

The oil mist is contaminated with combustion byproducts and needs to be removed. Part of the purpose of a PCV system is to "get rid of" the oil mist so that it cannot condense back to liquid and contaminate the oil.

Gordon0652

iTrader: (4)

Thank You!

MrDrezzUp

iTrader: (1)

Rumour has it that without a vacuum source a catch can will collect little to no oil.

Some people simply have a downward facing hose hanging off of the passenger side valve cover and downward facing hose hanging off of the valley cover. Thus any oil simply drips onto the ground while you are driving.

The drawback to any system that does not connect back to the intake is twofold. First, without a vacuum souce (e.g. intake) the contaminated mist is only removed from the crankcase as crankcase pressure "pushes" it out. Secondly, there is the environmental concern. Part of the PCV system's purposes is to recycle the contaminated oil mist back into the combustion chamber so that its burned.

SpinsB

iTrader: (5)

So just running a breather and having everything else capped off isnt a good thing? There seems to b alot of different set ups and different ways to run things? Seems alot depends on what vally cover we have and so on.. that true?

MrDrezzUp

iTrader: (1)

Having everything capped off and a breather does not provide as much ventilation as an oil breather cap, and a non-return catch can. My recommendation is for you to try capping everything off and install the oil breather cap, but not as a permanent solution. Use this setup to test if the PCV system is your oil consumption culprit. If the PCV system is the culprit then install a non-return catch to aid and increase crankcase ventilation.

Which valley cover used does play a huge part, because different valley covers can have different different sized PCV orifices.

SpinsB

iTrader: (5)

its an LS2 block so im guessing an LS2 vally cover. Long story about not really knowing what was used for my build(not getting into it) Lets say the PCV is the culprit of the oil consumption and I get a catch can from Cartek whats the way to hook it up? in my case assuming i have an LS2 vally cover grr not knowing is upsetting.....

SpinsB

iTrader: (5)

Thanks for all the info getting alot out of this MrDrezzUp

MrDrezzUp

iTrader: (1)

You are welcome!

The Carteck catch can has three ports. Two of the ports come with 90 degree elbows and the the third port has a plug on it. The fitting are interchangeable and Cartek provides a hose that you cut to the lengths you need. You have a variety of plumbing paths to pick and you simply pick the paths that you like best.