I did this breather mod and it eliminated the oily smell
 

I added a few check valves and a T fitting to my breather system and it totally eliminated the oily smell I was getting inside the car. Now the engine sucks from the valley under part throttle and idle which pulls air into the valve covers and through the breather box filters. Under boost the valley still evacuates into the breather box like before. I used 2 GM part #20861501 check valves but I bet many other check valves would work just as well.

It is worth noting that this mod introduces unmetered air into the manifold so it could / should effect the mass air reading at idle. I added some fittings that would allow me to quickly swap in different size jets incase I needed to restrict the flow of unmetered air into the system at idle. I started with a NX 136 jet (which has a 136 thousandths orifice) and it worked fine so I never went to anything smaller. It might work without a restrictor at all but I didn't try that.

I don't know if anyone else is wanting to eliminate the oil smell from their breather system but I thought I would pass my experience along just incase it helped any fellow forum members. I have attached a crude drawing of the routing and check valve placement.

Note - I have a wet sump car so I don't have the hose going to the middle of the passenger valve cover. I am not 100% sure if the line I drew from the center of the valve cover is how LMR recommends it....

assuming you have the breather tank by LMR right? You can send them your tank and they can update it to have the rerouted lines (to get rid of the smell) and quick connect fittings for the valve covers actually. It's supposed to be $200. They have my tank right now and are doing the upgrade to the new revision. I am not sure how long it is supposed to officially take to do the upgrade, but they received mine about 3 weeks ago (as of today) and I have been calling them at least once a week on what's going on and keep hearing "it should be ready to ship tomorrow or the day after". I personally think the time it's taking is starting to get a little excessive to weld on two fittings and put all the necessary fittings and hoses in a box to ship out but maybe they are just super busy right now. Their stuff is quality, so I'll wait for the best, but geez. lol.

Not a bad idea. You're essentially keeping the gases from seeping at idle or low speeds, which is when we smell them the most. :yesnod:

Ant, the official re-route still takes the gases to the scoop vent, I believe. I tried this and was a bit unhappy with still getting the smell.

You can use the hardware to do a relocate to the bottom of the compartment (ignore my fittings since you're getting yours re-done) like I did here - been happy with that, even though I'm sure it's not environmentally friendly. :rolleyes:

https://www.corvetteforum.com/forums...ng-option.html

I remember reading through that thread a while back. Looks like it's time to give it a reread. Thanks, Sean.

Mine smelled more at first but I think it was mostly the plastic of the filters or something because it isn't bad anymore, with the old style filters. The only time I ever get a whiff is on rapid deceleration to a stop or if I let it idle for longer than what I would consider normal, and even then, I am getting mostly exhaust smells than crankcase anyways since I have no cats.

Basically, I am not worried about it anymore, I am putting my ECS supercharger on next week and with boost we will see if it makes it worse.

I'm just going to hazard a guess and say 'yes' - it's been pretty awful for all of us with boosted setups, but here's hoping you get lucky! :cheers:

:iagree: Much Much happier now with the car with the factory blower.