Installed weistec catch can and just checked it for the first time after 1700 miles. There isn't a single drop of oil or anything in there. I'm wondering if there's an issue or if this is normal and I just need to check it after 10k miles or something. Starting to wonder if I wasted my money and this car doesn't really need this mod. Thoughts?

 

Should have stuff in it after 1700 miles maybe you are missing the filter element ? Or it's t not connected correctly?

 

your PCV is working and doing its job is why.

 

I'm not an expert here, but wouldn't this suggest that the PCV is not working? If the valve fails to open (stuck shut), then the crankcase vapors would never flow through the catch can, thus never condensing in the catch can. If it were functioning properly, it should allow flow into the intake plenum by passing through the can. Therefore, I would expect at least some condensate if it was functioning properly during that somewhat short run, even if it was just a film.

 

@BalanBro , great question. it would be impossible to be stick shut, the spring does not have enough tension and the flap valve will tear well before there is a spring failure of tension in most cases. if the does flap valve tear, it'll stay open. if the spring shrinks due to age and excessive use, the spring will hold the flap open ever so slightly bleeding off crankcase vapors allowing unmetered air into the intake stream past the metering device (MAF sensors). when the PCV is stuck open or if the spring isn't with enough tension bleeding crankcase vapor, this excess flow will pull oil vapor. the PCV is a regulated system which only allows for flows above a specific PSI of pressure into the intake stream. the M156 oil pump also will introduce a specific amount of vacuum suction at the bottom part of crankcase to suction oil.

i've spent a large number of hours researching and analyzing in efforts to redesign the M156 PCV system into an all in one aftermarket catch can. the simple but yet effective factory PCV valve, is a pretty exacting system that is designed specifically for the flow capacity of the M156. it isn't generic as generic of a PCV as one may think. it is meant to flow at the correct time breaking through initial spring seat tension to prevent crankcase fluid from escaping the crankcase. it also flows more air than any PCV available on any production engine ever from what i've been able to find. i know enough about the design and flow capabilities because i've spent hundreds of dollars purchasing multiple PCV systems to analyze and attempt to identify a higher flow unit than the M156's.

and for those others who are wondering what the PCV system does, it is to expel crankcase vapor in a safe manner, to bleed off additional crankcase pressure, and to provide suction to the piston rings at the right time to aid in sealing which promotes power production.

 

If everything is working than the can should be collecting something. Even if it's just clear water condensate. The fact he has none suggests something is off somewhere

 

I have an update. Checked my catch can after 3000 miles and here is what was in it. Maybe a few tea spoons worth. Interesting that there was something in it this time as opposed to my first check.

 

Looks like some condensation caught there.

 

I definitely get a mix of oil and water in mine. I also don't get a big volume either, only a 1/4 inch or so.

 

What oil are you using? Our track car usually gets more darker (just pure engine oil) blowby oil caught.

This looks like some lifter or ceramide additives are filtered. some of the compounds in additives have lower flash points and turn into its steam and adversely get spat out the pcv.

 

liqui Molly high tech 5w40. I also added 2 bottles of Ceretec about 6k miles ago.

 

Good timing on the catch can. That ceratec stuff fouls the intake manifold without it.

 

good thing it was the first tine i've used it then. Probably won't touch it again for 20k mile intervals

 

Please explain further as so many on here have used Ceratec including myself?

 

Explained it on this post. If you read the data sheet on ceratec its flash point (where liquid turns to gas) where it turns to vapour is low. It gets caught in blowby through pcv and without a catch can to filter the vapour, it gets spat out into the intake manifold.