PCV question???

[pbm]

My 2001 Honda Accord PCV valve seems to stop 'rattling' every couple of weeks. I thought it was due to the aftermarket (Fram and Purolator) PVC valves but it's still doing it with a $20 Honda OE valve. In contrast, my 2002 Buick still rattles while using a Purolator after a year of usage. What causes the Honda to gum up and what can I do to fix it? I do notice that oil usage and PCV valve 'gumming' seem to go hand in hand.

Could somebody explain the 'catch can' thing?

 

[willix]

Someone posted a nice DIY set up with great pics not that long ago.

 

[UNC017]

Originally Posted By: willix
Someone posted a nice DIY set up with great pics not that long ago.


Are you referring to the thread I started? Lots of good ideas from other folks on that thread, including the Porsche OEM trap and part number.

https://bobistheoilguy.com/forums/posts/1728352/

FWIW, my little home-brew trap seems to have knocked down oil consumption on the PT Cruiser by more than a factor of 2. I ultimately wound up not even using the filter mesh in the glass fuel filter- just the drop in air velocity catches most of the liquid oil and holds it in the bottom 1/3 of the trap, and when you shut the engine down it drains back into the valve cover through the PCV valve. It would work even better with a bigger volume trap, and probably if I relocated the PCV valve itself to the other side of the trap.

 

[mechtech2]

Rattling is not a good test of a PCV.
It can rattle and be bad in a number of ways.
No rattle because of gunk means it needs to be cleaned. But some don't rattle when brand new.

The catch can comes AFTER the PCV valve. Therefore it won't keep it clean. It keeps the manifold, throttle body, ports, valves, and combustion chamber cleaner. But this is AFTER the actual valve.

Make sure your other end of the PCV system is open and breathing . Usually a vent or breather on the valve cover. A loose VC that sucks air will cause anomalies, too.
Cold weather and short trips make PCV gunk worse.


BTW, I use a catch can. For my smaller engine I use a common air line water separator sold at Home Depot, Menards, etc..
Install it with the flow arrows backwards, and remove the filter for good flow, esp in winter. Under $20 for the pice and barbed fittings.

 

[pbm]

After reading 440Magnums Dec. thread I came up with a plan.
I removed the PCV valve from the valve cover and fitted a 1/2" brass barbed hose connector into the opening. It fit pretty snugly but I wrapped some duct tape around it to make sure. I attached approximately 3 1/2" of 1/2" heater hose to the barbed connector and then attached my PCV valve to that. I replaced the hose on other side of the PCV valve with a longer piece and put an upward loop in the hose.

What I now have is my PCV valve sitting about 3 1/2" above the valve cover connected by a (larger ID) hose. If any oil vapors are able to overcome the additional gravity they would still have even more additional gravity from the other side of the PCV valve to the manifold. I'm hoping that this keeps more oil in the engine and also keeps the PCV valve 'rattling'.

Does anybody see any problem with this? Thanks

 

[willix]

Thats it 440, I like it. How is that simple setup working out? It it separating vapors well enough?

 

[mechtech2]

pbm - What is coming out is not oil [OK, maybe a little], but blowby vapors and water [a product of gas combustion].

Oil vapors are induced in the PCV system by engine vacuum, not gravity.

If you have such severe PCV gunk problems that it requires a pre filter to it, then you have engine problems.