PCV valve replacement
#1
PCV valve replacement
Just thought I would share another fruitful experience. PCV or positive crankcase ventilation valve recirculates hot gases back into the intake during idle or slow driving. You can see after 11 years the carbon builds up and starts to either block up the system or prevent valve from functioning properly. OEM is only $9.
Part number: 12204-50030
http://www.lexussouthatlantaparts.co...220450030.html
Part number: 12204-50030
http://www.lexussouthatlantaparts.co...220450030.html
#3
New oem part comes with coating on the threads. It's pretty easy to replace. Be careful of the spark plug wire right there. I unplugged it and removed one bracket. I would clean all around it before removing so nothing falls into the valve cover. It takes a little work to get a good grip and turn it. Not a lot of room. I think vice grips ended up being the easiest tool I had to remove it.
Last edited by Lavrishevo; 04-22-15 at 08:21 AM.
#4
What a nice improvement over the 400.... that design was a rubber grommet in the valve cover that the PCV valve plugged into. Over time/miles...that grommet gets hard as a rock and pretty useless... have to replace both the PCV valve and grommet at the same time. And usually the grommet breaks inside the valve cover and you have to dig it out. Fortunately there is a cover on the underside so it does not fall so far.
And timely recommendation on this maintenance item. Don't forget to check your hose for blockage and cracks....often times they need to be replaced also. Thanks Lav..
And timely recommendation on this maintenance item. Don't forget to check your hose for blockage and cracks....often times they need to be replaced also. Thanks Lav..
#6
The valve being stuck open or closed is not a good thing. It does a lot more then I realized, not just emissions.
http://www.agcoauto.com/content/news/p2_articleid/197
http://www.agcoauto.com/content/news/p2_articleid/197
Last edited by Lavrishevo; 04-22-15 at 10:45 AM.
#7
Pole Position
PCV allows vacuum air from under valve cover to be recirculated into air intake and back into combustion ... (was the first rudimentary pollution device first installed on late 60's autos). A sticky PCV can cause slightly rough idle. Rather than replace it, a PCV can be soaked and cleaned with a solvent or spray Gumout-type product.
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#8
And a clogged PCV valve could lead to valve cover gasket leakage as the air pressure build up looks to escape some place, and oil follows soon after that. For the price and hassle... I'd just as soon replace than attempt to clean.
#10
I think you are right. Looks like 01-03 is a slightly different design. It's plastic with a grommet.
http://www.lexussouthatlantaparts.co...ssembly=770277
http://www.lexussouthatlantaparts.co...ssembly=770277
#12
Lexus Test Driver
The valve being stuck open or closed is not a good thing. It does a lot more then I realized, not just emissions.
http://www.agcoauto.com/content/news/p2_articleid/197
http://www.agcoauto.com/content/news/p2_articleid/197
#13
I mentioned this above... if it is very old with lots of miles and never been replaced, you can expect it to either break or be useless in holding the new PCV valve in. When it breaks when you try to remove it, it does not fall into the engine, but rather the containment shelf in the inside of the valve cover. You can from this point, use needle nose pliers to pull it out from the ledge it's resting on. It will need to be, at least, broken in half to get it out.
#14
I have theory that the reason some people are loosing valve cover gaskets a lot earlier then others is related to clogged or malfunctioning PCV valves. It's interesting to look at.
You know what's odd. The part for my 04 came with a grommet that looks like the same one for the 01-03. No place for a grommet on the 04 that I saw. Just screws out and back in again.
You know what's odd. The part for my 04 came with a grommet that looks like the same one for the 01-03. No place for a grommet on the 04 that I saw. Just screws out and back in again.
#15
I'd rather have the ghetto PCV valve then be unable to change my tranny fluid with ease like I can now.. tradeoff I guess between gen3 and gen4 ! jk
Concerning the valve cover gaskets.. leakage from the gasket would have nothing to do with how hard you run the motor right?? since there is little pressure there?
I also read somewhere(and this could be totally wrong) that if you drive less than 20 mins at a time then you may not be allowing the motor to heat up enough for the PCV valve to kick in and release water/moisture from the system and thus wouldn't be burning off the water that is now mixing in with oil.
Concerning the valve cover gaskets.. leakage from the gasket would have nothing to do with how hard you run the motor right?? since there is little pressure there?
I also read somewhere(and this could be totally wrong) that if you drive less than 20 mins at a time then you may not be allowing the motor to heat up enough for the PCV valve to kick in and release water/moisture from the system and thus wouldn't be burning off the water that is now mixing in with oil.
Last edited by KawiLex; 04-24-15 at 02:16 PM.