PCV system upgrade

[BCChevyZ71]

So I haven't seen anyone do a write up on this I will assume maybe it hasn't been done yet. My 98 k1500 when I got it was very poorly maintained amongst the list of things that didn't get any love was the PCV system. I replaced the boots and grommets and the PCV valve itself and while consistently pulling apart the intake system and cleaning years of neglect. I noticed oil in the intake tract which I personally am not a huge fan of though its common at least in many trucks I've owned. I tried fram, ac delco, and other brands of PCV valves my local parts store offers for ***** and giggles. While in my searches on the interwebs I found a write up from the NBS 5.3 guys a hidden gem in a GM re call service bulletin about the LS 5.3 trucks using a similar PCV valve as the 5.7 vortec and seeing oil usage through the PCV system via the intake. The fix? A fixed orifice PCV valve no more spring .etc I sent my local parts house on a wild goose hunt to find me one......I have since lost the part number but one could search up the service bulletin and cross reference part numbers as I did. Long story short upon switching to the fixed orifice not only do I no longer see traces of oil on my intake but I firmly believe the PCV system is working far far far better then it ever did with an OEM style PCV valve. As well I will never have to replace my PCV valve again because it's no longer containing any moving parts springs .etc I can pull it off clean it with brake clean dry it out and re install. I couldn't tell you why it works so much better but I can tell you that since switching the pcv i still haven't developed any blow by or any kind of negative adverse anything and i have a perfect just enough Suction to hold a dollar bill to the oil fill tube while running. 302,000 km and I no longer have oil in the intake at least that I notice and for the 10 ish dollars it cost me its my favorite and best bang for my buck mod I've ever done on my truck.

 

[BCChevyZ71]

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://www.mightyautoparts.com/wp-content/uploads/2019/10/tt-0122-crankcase-ventilation.pdf&ved=2ahUKEwizmZmQ6732AhUCKn0KHQacBFIQFnoECAkQAQ&usg=AOvVaw1OC_9uOBqfeV9mLFWygfIf

Here is a link with a basic write up and part numbers explaining the same basic thing as I have. You should be able to take the part number and cross reference it and be able to do the same modification as me should you decide to

 

[Leeztruk]

Just installed one into my LS 4.8L. Basically just a PCV shell with a fixed orifice.

 

[herkyhawki]

....I can tell you that since switching I have zero blow by .....

It's unlikely that changing a PCV valve will suddenly make the piston rings form a perfect seal and stop all blowby in a 302,000km engine. Maybe the new PCV is doing a better job of sucking the blowby back to intake, but it does not eliminate blowby.

 

[BCChevyZ71]

It's unlikely that changing a PCV valve will suddenly make the piston rings form a perfect seal and stop all blowby in a 302,000km engine. Maybe the new PCV is doing a better job of sucking the blowby back to intake, but it does not eliminate blowby.

Was meant more as switching the PCV hasn't caused issues. I never had any blowby the pcv never worked incorrectly aside from me not being crazy about the bit of oil I got in the air hat I edited the original post to not confuse anyone

 

[highwaystar]

Wonder if this will work on a '94. My dipstick had corrosion on it, I cleaned it, came back so cleaned it again. scratching my head, I checked the pcv valve and low and behold it was gummed up. Installed a new valve and all is good now. '94 mods?

 

[BCChevyZ71]

Wonder if this will work on a '94. My dipstick had corrosion on it, I cleaned it, came back so cleaned it again. scratching my head, I checked the pcv valve and low and behold it was gummed up. Installed a new valve and all is good now. '94 mods?

I'd say try it, and just see how it goes I know it worked on my truck

 

[Schurkey]

If the problem is oil in the intake system from the PCV valve (not some other cause) then the better "fix" is to repair/replace the oil baffles in the valve covers.

Folks go crazy "fixing" oil/water in the PCV leading to oil in the intake system; but the PCV valve should never be in contact with liquid oil. Water in the PCV plumbing--and therefore in the intake--is a huge part of why the system was invented to begin with. Of course there's water in the PCV system.

If the engine has adequate oil baffles, then there's excessive blow-by.

"Gutless" PCV "valves" are not progress, it's an example of lazy, cost-cutting GM engineering.

 

[Supercharged111]

If you do have blowby, and you don't want to fix it, you can address the breather like I did. The 350 Vortec has a pretty good breather tube stock, but the LT1 and 454 Vortec just got a single 3/8"/10mm hose like the LS motors which is grossly inadequate. For my LT1, I installed a 350 truck valve cover and ran that to a catch can. That car is speed density so no need to obsess over it venting to the atmosphere. For my dually, I punched a hole in the oil filler cap and ran a 3/4" hose from it to the intake elbow after the MAF, same as how the 350 was set up. Both vehicles reduced oil consumption to an acceptable level. I will caveat that my LT1 sees extended WOT operation and the dually is boosted. Without the blower I had no issues. Mighty Mouse makes a baffle that goes into the oil cap hole for an LS motor and they have generous hose outlet sizes. Baffles are absolutely mandatory, without them you can drive your oil consumption significantly higher.

 

[BCChevyZ71]

My truck has no blowby runs immaculately doesn't burn oil and I firmly believe the fixed orifice PCV was the key to fixing my oil in the intake issue. If its not something you believe in or care for that's cool it worked for me and does so day in and day out idk so I figured I'd pass it along.