I have a 94 6 speed with a remote mount turbo setup with 10 lbs of boost and i am noticing that when I come off boost I am getting a little bit of blow by and it seems like some oil is coming out of the dipstick. I have a stock PCV valve and i have tried a one way check valve however the check valve just seemed to make things worse. What should I do to fix this?

 

Hi

You need to block the pcv hose, remove the dipstick and cap it.
I have a custom valve cover cap with a hose to an oil catch can.

Any vacuum port can be influenced by the blowby and pressurizes the crankcase forcing oil out the dipstick and seals.
Cheers

 

I am having trouble envisioning this do you have any pictures of a catch can setup

 

Are you saying you disabled the pcv and blocked off the oil dipstick tube, making the valve cover breathrs the only orifice oil can come out of ...at which point it goes into a catch can.....

 

How are you brakes hooked up?

 

Just the way the way they came from the factory vacuum

 

Do I have to modify how the brakes are setup with the vacuum assist

 

Yes, it needs a check valve so the brake booster doesn't see, well boost.

Otherwise your vacuum assist will turn into boost detriment

 

Do you have any detailed pics of your PCV and brake setup

 

no, I need to take some

 

Can you grab some pics for me please I need to get this sorted out

 

I would be interested in seeing these pictures as well. I was pushing oil out the front seals with my oil cap on and just for a temporary setup I put a filler neck from a Tahoe on my valve cover fill and zip tied a rag to the neck of it so it can relieve the pressure.looks pretty hokey but it works for now.

 

OK some practical history here. First the checkvalve on the brake booster is a checkvalve. If it fails you may damage your booster but it is rare. However all my kits include a checkvale to insert in-line because a checkvalve is a hell of a lot less money than a new booster !!!!

Next - do you need a PCV valve. No not really but it is a GOOD thing to have as it cleans your crankcase during normal driving. Most PCV valves will leak a little boost to crankcase under boosted conditions so good to add an in-line checkvalve to the PCV system if one is to keep. A decent checkvalve may cost you $15. On the LTx difficult to add because of the little 'U' tube hose but can be done. I made an integral PCV and check but too expensive.

Crankcase Breathing: First if you blow out the dipstick buy a new one. The rubber seal goes bad. If you blow out the new dipstick you have a serious blow-by issue (assuming open breathers on each valve cover) !!!!!!!!!!! And with that I recommend open breathers on each valve cover. If emissions inspection require closed loop then get breathers with hose connections and connect to air filter.

So after all of the above you are still dripping oil: THEN get a new and professional engine builder ! A properly built SBC engine under 15 pounds of boost will not blow oil out breathers and require an exotic catch-can system !!!!!!!!

But if you must blow oil then by all means build your self a really good catch can system !!!!!!!!!!!! LOL
greg

 

Thanks for the info Greg (by the way this is Kurt Hill) When you have a chance send me that e mail on the logging set up. I don't think I got it yet. I am back from Power Tour and the car survived the trip from Madison to Baton Rouge (barely) I have some work to do. I really want this car "right" and I have not given up (YET!)

 

Let me clear up some misconceptions from my original post...I am not blowing my dipstick out of the tube however some oil is blowing out the dipstick tube under high boost and i get some puffs of smoke out of the exhaust. How much is one of these modified pcv check valve things and how do i order them. I have a feeling that my check valve may be causing a too much of a restriction on the system because it may be too small and not allowing proper flow... what kind of check valve do i need.... here is the one I currently have

http://www.mcmaster.com/#7775k52/=xonspv

 

A good checkvalve is $15

I suggest you first cap off the PCV system and replace the oil dipstick with a new one.
Then if you have open breathers on each valve cover there should be no oil dripping from dipstick tube.

Are the puffs of smoke under WOT or when you lift ?

 

When I lift after I hit boost

 

who sells a reasonable but decent set of valve covers that has breathers on both sides? I'm running the stock set so I've only got the oil filler as a breather on the passenger side. Will that be enough with a catch can setup? and with proper breeders do you still need to cap the PVC system?Also anybody have pictures or ideas for their catch cans?

 

Need a good working Pcv system or the hydrocarbons will start to break down the detergents etc in the oil..

 

I do have a decent pic of my breather setup
The long tubes are in case there is blowby, it won't start a fire