Mods are in sig, but I do want to say in advance I have the STM Standard Catch Can with -6AN fittings, hooked up the way they suggest it. My car never burnt oil before this.


Alright, last March I had to do the head gasket on my car, it has 70k miles on a stock bottom end, and has never burnt oil. Turbo might have 5k miles on it.



While the head was off for a head gasket, I decided to install ARP studs, GSC S2's, and beehive springs. So, off the head came, and was sent to a very reputable local machine shop. I had them do a valve job, pressure check, surface, and install new OEM valve seals at the same time they installed my GSC Beehive springs. Fast forward to getting the car back going. I made the trip to the dyno, got tuned, and have been driving it a little since then. This car is not a daily, I have only put 2k on it since last March




I have noticed when I pull up to a red light or anytime sitting at idle when warm, oil smoke from the catch can breather comes through the hood vent. Also, when riding down the road with the sunroof open, I can smell the smell of oil burning coming in the car.The car is not smoking through the tail pipe. There is NO oil smoke at all coming from the exhaust, just from the catch can breather. ALSO THERE IS NO LEAKS AT ALL. The car is so clean under the hood you could eat off of it.





I have been driving like a Grandma unless I have to pull out in front of someone, or pass someone. In the 2,000 miles since I have put the new head gasket on and installed the GSC S2's, I have burnt 1.5 quarts of oil. I'm pretty sure 1/5 or 3/4 of a quart of that was from the dyno day. But, This is super annoying as the car never burnt any oil from change to change before. Not to mention to pull up and smell that crap, and not be able to ride with my sunroof open, because if I am going somewhere that I have to be presentable, I'll smell like ***.



I have read somewhere in the past, that maybe the -6an fittings on the catch can could be causing this, but as stated, it never burnt oil before the S2 install.

Anyone else with S2's on a stock bottom end having this issue?

 

S2s stock bottom end. No increase of oil consumption. The car has always used 1/4-1/2 qt over a 3k drain interval in the ~14 yrs I've owned it.

I'd think that if the issue was with the work performed at the machine shop you'd see it out the exhaust. My guess it has to do with the OCC/PCV/breather hose set up but it's just a guess.

Another possibility is how much assembly lube if any was on the cams when the head went back in

 

I used the same amount that I have always used on previous engine builds/cam installs. The cam journals/caps surfaces were coated completely, as well as the cam itself.

I have always used this and never had an issue with it.

I'm trying to find the post that I saw when I first was looking at catch cans.

Someone had stated they had oil consumption issues with their STM can with -6ANn fittings and changed it to -10AN fittings and it went away.

 

Found it....couple of posts down..FP turbos apparently don't like the small -6 fittings?

https://www.evolutionm.net/forums/ev...issues-70.html

 

Is your green a ball bearing? It would only be an issue with the turbo if you're seeing smoke out the exhaust.


Did the machine shop do a valve job?


Have you done a leak down test?


Sometimes, when you put a fresh head on a used bottom end, it can cause increased blow by at the rings. This is due to the used/worn rings having to deal with a little more pressure do to having a nice brand new and perfectly sealed head on top of them. I have personally seen this. Did head on a Ford 4.6 with 100k on it, motor was in great shap, used no oil, just burnt an exhaust valve. With new heads on it, it started using a quart of oil every 1500 miles or so. Inspection revealed no issues with the head (valve seales, etc). So we ordered a reman short black from ford, put it in without touching the heads (just put them on the new block), problem solved.

 

No my Green isn't a ball bearing, still old school journal bearing.



Yes, the machine shop did a valve job as well, forgot to put this in my initial post.


Haven't done a leak down test.


Bottom end has 70k miles on it, the last 20k have been at 28-30psi that I know of

 

Could it be possible for the valve stem seals to be leaking? Were they replaced with the new valves?

-pal215

 

**Usually** valve stem seal leaks cause smoke from the exhaust. And they wouldn't cause smoke from the catch breather.

 

Yes they were replaced...and that would be smoking through the exhaust.

 

Correct, and who in their right mind wouldn't replace valve stem seals when the head is in the shop to have a valve job and new springs installed

 

I would do a leak down test and see what you find.

 

Sometime if you don't seat the valve stem seal down well, it can slide up and...start sucking oil into the guide.

Perhaps verifying they are all seated properly is first thing to try?
Check plugs, 1 may show something, or may not, as it may be so slight of an oil leak.

 

I had a DSM that started using oil at about the same rate as above and no visible smoke. It was valve seals.

 

All plugs pulled and checked perfect color..none were damp with a trace of anything

 

remove valve cover and veryfy that the valve stem seals are in place..