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Last year i put a Harbor Freight (same has Home Depot) catch can between the PCV valve and the intake upper collector.
From the beginning it worked well and I generally have to empty it once per tank of gas, but this is a very small amount of oil.
A couple weeks ago, when I replaced my rear valve cover I realized there is still some oil in the upper collector but it's mostly upstream from PCV inlet, all the way up to the throttle body.
So I decided to put a 2nd catch can between the front valve cover and the helmholtz resonator.
After about 100 miles, the thing is completely bone dry. I do have the input and output attached correctly, I'm sure of that.
Has anyone here had any luck with a 2nd catch can?
Interesting. Especially since I'm in the middle of replacing both of my valve covers. I have no suggestions however. Curious how it works over time, if at all.
The rear valve cover gasket you replaced had a leak in it allowing the engine to breathe in moisture.
I had the exact same experience with the VQ30DE on my 98. I installed a PCV catch can from the front valve cover to the resonator because I noticed thin watery oil collecting inside the resonator. When I installed the catch can it collected a very thin watery oil that I had to empty 10x more often than the catch can I had hooked directly to the PCV valve on the rear cover.
When I replaced the rear valve cover gasket alone last spring the front valve cover catch can has been bone dry since.
I NEVER would have thought of that but it does make sense.
How much was your rear valve cover gasket leaking? Was it a huge amount? Also, what condition was the bad gasket in when you took it out? Did it look really bad?
I NEVER would have thought of that but it does make sense.
How much was your rear valve cover gasket leaking? Was it a huge amount? Also, what condition was the bad gasket in when you took it out? Did it look really bad?
Thanks
The leak was so minor that no oil ever leaked out. The gasket was in good condition. The one I installed last spring that fixed the leak is the same brand and PN. The valve cover bolts were either not torqued enough or it was the ultra grey sealant. Only black sealant should be used on our valve covers. It's more oil resistant and made to seal rubber to metal. Ultra grey is for metal to metal.
The easiest way to determine if our valve covers are leaking is the rear catch can connected straight to the PCV valve. If it's creamy and not the same color as the motor oil then there's a leak on either valve cover. The reason the rear catch can gets creamy during the leak instead of watery like the front is it has much higher suction. Most of the moisture is being burned in the chambers. Only a small amount gets mixed with oil making it look creamy. The front catch can gets much less suction so it collects no oil.
How did you know there was a leak if no oil leaked out? Was it purely because the catch can oil was milky?
I wish I had known about using black sealant. I went with the grey per the FSM. Is there a particular black sealant that you recommend?
The oil in the catch can on my PCV looks like regular motor oil and it always has, not milky at all, but I definitely had a leak on the rear of the VC.
One last question. How long did you let the sealant cure before starting the car?
Since replacing the rear valve cover gasket alone the rear catch can is now the same color as the motor oil. No longer creamy.
Permatex Ultra Black Sealant. The several Felpro valve cover gasket kits I purchased over the years all come with that ultra black. Another member in the 4th GEN forum also has had better luck with ultra black on the handful of 4ths he owns.
I let the sealant dry overnight for 16 hours in warm weather.
09-24-2017, 10:33 PM
