[rcoe]

Had track day today, car has been perfect all year no issues.

About 10 minutes in they flag me to come in, said I had white smoke coming out exhaust and they did not want me to damage the engine. I could not tell and car was running great, everything on gauges right where it should be.

Looks like the catch can was full and pushing fluid past the back into the intake.

Cleaned it up and drained the catch can. Went back out taking it a little easier and got almost 20 minutes, no smoke and noticed a small spray on my windshield that came from the vent in my Anderson hood.

Catch can was completely full. Thinking I was getting a bunch of blow by open the vents on my covers with it idling zero pressure. Pulled the #1 and #3 plugs as they are the only ones I can get out while it was hot, little oil on the bottom of the plug and 1st couple threads but tip looked good on both.

Just seems like it happens during sustained high rpm runs. Nothing really looks off in HPtuners, no misfires or anything else that I could see.

Any ideas, valves/springs or maybe rings?

[dreksnot]

What brand catch can and how do you have it installed? PCV setup or draft setup?

I had big issues with my LSX. The combination of the valve covers, where and how the vent tubing was - was the big issue. Answer the above and maybe I can lead you.

[rcoe]

Thanks

Weapon X baffled covers
mighty mouse wild

one valve cover is vented to factory location far left position
other cover goes to the large inlet on the can
small port with check ball goes to intake manifold vac.

[Joshinator99]

Originally Posted by rcoe

Thanks

Weapon X baffled covers
mighty mouse wild

one valve cover is vented to factory location far left position
other cover goes to the large inlet on the can
small port with check ball goes to intake manifold vac.

The valve covers are almost guaranteed to be at fault. The baffling on virtually all aftermarket valve covers are garbage compared to OEM (except the THPSI ones, they’re solid) and I’ve yet to see Weapon X make anything properly thought out unfortunately. If you reach out to MM I believe he’ll suggest a small restrictor that helps but doesn’t fix the valve cover design issue.

Also, obligatory post about your coolant being low lol

[rcoe]

Originally Posted by Joshinator99

The valve covers are almost guaranteed to be at fault. The baffling on virtually all aftermarket valve covers are garbage compared to OEM (except the THPSI ones, they’re solid) and I’ve yet to see Weapon X make anything properly thought out unfortunately. If you reach out to MM I believe he’ll suggest a small restrictor that helps but doesn’t fix the valve cover design issue.

Also, obligatory post about your coolant being low lol

Might need to switch the covers out, too bad they look really good.

Old picture and I am almost certain you posted about the coolant level back then, she is always full now.

[AZIROC]

So I had this issue last year. Same scenario. 3 laps in and it looks like I blew my engine cause of all the smoke **I even have a post somewhere about it** needless to say I was having a huge oh shit moment. Then when i got back to the pit I was now confused cause everything LOOKED right.

Anywho, the issue was the catch can version is wrong. For zl1s/boosted applications, you need the mighty mouse MILD version with the recirculating head (not the vented head).

What happens with the wild version is the exact opposite of what the catch can is suppose to do. Under hard acceleration, specially turning, and under positive boost pressure, the oil gets SUCKED out of the driver side valve cover INTO the catch can and then forced into the blower/intake. Oh...and any excess gets shot out the vented top and all over your engine bay and the potential of an engine fire goes through the roof.

The correct setup is again, the mild with recirculating top. Do that, no issues.


Edit:

Saw you have aftermarket valve covers. I hate to say it, but sell them and get OEM ones. Most aftermarket valve covers, while look amazing, aren't as good as oem baffling.


Oh...and your coolant is low. Lol

[rcoe]

Originally Posted by AZIROC

So I had this issue last year. Same scenario. 3 laps in and it looks like I blew my engine cause of all the smoke **I even have a post somewhere about it** needless to say I was having a huge oh shit moment. Then when i got back to the pit I was now confused cause everything LOOKED right.

That is exactly the same, I noticed the misting on the windshield and figured it was the car in front of me. Until they flagged me to come in. I have done many high speed passes this year with zero problems, but I guess 30 seconds of WOT is not the same as really flogging the car for a 20 minute session. Too bad my day was cut short as I had already improved on my personal best by close to 10 seconds.

Looks like MM sells just the cap to go on my can to convert it to a sealed unit, thinking this should work. Then to decide on whether to go back to stock covers or spend $$ for the TooHighPsi ones. Can probably get ma couple buck for the weaponX ones on marketplace.

Thanks for letting me know I am not the only one who has had this issue.

[ctrlz]

Originally Posted by AZIROC

Anywho, the issue was the catch can version is wrong. For zl1s/boosted applications, you need the mighty mouse MILD version with the recirculating head (not the vented head).

What happens with the wild version is the exact opposite of what the catch can is suppose to do. Under hard acceleration, specially turning, and under positive boost pressure, the oil gets SUCKED out of the driver side valve cover INTO the catch can and then forced into the blower/intake. Oh...and any excess gets shot out the vented top and all over your engine bay and the potential of an engine fire goes through the roof.

The correct setup is again, the mild with recirculating top. Do that, no issues.

They should include a Voodoo Priestess and a Doctor of Physics with every one of these catch cans!
There can be so much to getting these right.
Nice write up, and good luck to rcoe!

[dreksnot]

To expand on what my issues was and most certainly sounds similar to yours, but mine's a lengthy story.

Since I was pushing x,xxx hp, I needed more crankcase venting. So, I went bigger, and dual MM catch cans (cc) (-12AN and -10AN tubing). The "larger" one was a vented setup PCV off the passenger side valve cover off the oil-fill cap location, check-valve line behind the throttle body on the intake, while the "smaller" was venting on the driver's side valve cover rear OEM location.

OEM valve covers: First indication of trouble. Autocrossing and the hard turns and braking. Right after a hard (boosted) acceleration and releasing the throttle, positive crankcase pressure would vent into the cans AND the check-valve would go from closed to open allowing the unmetered air from the PS cc to pull air from that can/vent into the intake. But, since the oil-fill location was on the front of the valve cover, guess what oil in the valve covers does while turning hard and braking? A combination of the crankcase venting behind the oil and the vacuum from the intake pulled oil into the can, filling it quickly and thus sucking into the motor to make for the nice smoke screen at autocross, and misting the engine bay, windshield and the whole rear of the back bumper. Nasty cleanup, nonetheless. (a thought was to weld bungs in the middle-top of the OEM valve covers where oil doesn't get slammed (front or back))

So, attempt Number Two was to swap out the OEM valve covers because I thought I needed way move venting capacity. So, here goes with BTR "baffled" valve covers on. Those had hefty -12AN fittings on the front and rear of the valve covers. So, I thought trying the rear location on the PS might just work since the front on the OEM's didn't. Heck, I would have to accelerate mighty hard and the oil would have to run a longer distance from the rear valve cover against the forces of acceleration, right? So, I was at the TX Mile for this sortie. Let me say the BTR baffles were a joke. I filled up the cc's midway through the run, misting the windshield, oil-washing the whole rear of the bumper, engine bay looked like a spattered mess. (BTW, oil injection is a frowned upon octane reduction method)

I contacted Dave at MM seeking input but nothing really came about. Also, my engine builder suggested a puke can. I didn't want a band-aid.

Attempt Number Three. I searched and searched and found Motion Raceworks baffled valve covers. The baffling looked OEM-like but much more venting capacity. Calls to them only yielded a pitch of how well they would work for me with the x,xxx hp and required venting. So, WTH and let's give it a try. The VERDICT was they were head and shoulders better with their method of baffling and along with my setup reduced oil "transfer" remarkably, like getting 2-4 ounces in the PCV can on PS (almost nothing in the draft can on DS) versus overflowing the PCV side after a race day or a few months of daily. So, Motion Racework valve covers provided a HUGE improvement!

One more thing I did (and perhaps the only thing I would have needed to do in the first place) was to insert a manual ball-valve between the PCV check-valve and the cc. This, I thought, I could shut during extreme driving so my cc setups would be draft (no PCV to be able to pull oil into the intake). I never got around to trying it but I thought in principle, it would work. Keep the valve open for daily driving and less cockpit smell, close for racing. Hell, this $15 item and 1-minute installation could have been the simple fix the whole time..... and the more I think about it, the less I want to think about it

[rcoe]

Originally Posted by dreksnot

One more thing I did (and perhaps the only thing I would have needed to do in the first place) was to insert a manual ball-valve between the PCV check-valve and the cc. This, I thought, I could shut during extreme driving so my cc setups would be draft (no PCV to be able to pull oil into the intake). I never got around to trying it but I thought in principle, it would work. Keep the valve open for daily driving and less cockpit smell, close for racing. Hell, this $15 item and 1-minute installation could have been the simple fix the whole time..... and the more I think about it, the less I want to think about it

Funny what I ended up doing to keep the oil from back flowing into the intake was use a fancy set of small vice grips to gently close the line going to the intake manifold. This kept the oil out of the intake and I had no more smoking out the tail pipe, still over flowed the catch can and made a mess.

[rcoe]

Well learning more about catch cans than I thought I would ever need.

For all the newer (2020) MM catch can the center section is rotatable and can change what ports do what.

There are 2 different exit ports depending on application that should go back to the intake manifold or vac. source. This should have the check valve fitting.

The other is just a hole where you can see the metal media inside, this is the inlet from either the crankcase or valve cover. Open fitting.

Mine have been backwards. This might not completely solve my issues but would help to at least have it plumbed correctly. MM also says for track use I need their sealed cover and to have it setup as a mild.

Will try this, hoping this might fix it so I don't need to by new valve covers.

[AZIROC]

Good luck and keep us posted. I called MM when I had my issue and they were great. Mostly cause they were able to dumb down everything to a 5th grade level to where I understood it. Lol