bob2200

[Part 1 of 2]

Thanks for the help in discovering how to remove the V-Bank Cover.

Now I can't seem to figure out which is the PCV (Positive Crankcase Ventilation) device. I went to my local Lexus dealer and bought a replacement (#12204-20040), but nothing seems to look like it. The closest part I see, with a hose to the throttle body, is this one:

bob2200

[Part 2 of 2

The part from the dealer looks like this:

Lexmex

I am not sure what that part is in your second post. This is what I have referred to as the PCV valve before.

Wikipedia does a great job of explaining the importance of this device, http://en.wikipedia.org/wiki/PCV_valve

Last time I got one at Lexus under $5 USD from what I remember.

bob2200

I think I found the answer, using the search function, now that I got the part number from the Lexus dealer. The photo was on this forum back in 2004. It wasn't obvious to me without this photo.

HarrierAWD

I am not sure Wikipedia has the correct description (didn't read the whole thing.) I always thought that the PCV valve allow polluted crankcase air back to the air intake and get it re-burned. It helps keep the engine clean and reduce crankcase emission. It doesn't introduce fresh air into crankcase.

His 2nd post looks like a PCV valve. I haven't changed mine so I don't know what Lexus' look like. It looks similar to my old car's.

Lexmex

LOL. True, but the air would be a lot dirtier if they didn't have that valve. What you just described does indeed occur. That is why I was going to use a cleaner in the throttle body to get rid of any gunk in there given the way the PCV valve works in the RX300.

That PCV Valve is a plastic L piece. The wikipedia article has a photo that looks almost identical.

hitthepin

Lexmex, correct me if I'm wrong. I thought(which is dangerous) depending on the year of the RX the PCV valve is either a black plastic L-shape or the metal threaded part bobo posted in the earlier post. Yes, No??

Lexmex

I always understood the piece in the RX (at least mine to) be the plastic L-shaped piece, not the metal piece. They have may slightly altered the design in one of the later versions of the RX (perhaps 2001+), but I don't have another RX300 I know of for at least 800 miles away to check.

In that picture that also shows a metal piece in a similar location to mine, I can see part of the L-plastic piece sticking into it.

When I went to the dealership in Naples, Florida while on a trip, I asked for the PCV Valve (made no reference to year) and the plastic L-shaped piece is what they gave me.

hitthepin

hmmm? I'm actually glad this thread came up since I'm going to be changing this part on our 02' Rx. I've changed the PCV valve on my father's 99 Rx300 and it is the plastic L-shape piece you describe.

So without being a 100% sure I thought(maybe I read somewhere) that 02' models, the PCV is the metal part bob2200 posted. I'm going to pop the hood this weekend to have a peak at it before going to the dealership to buy the part.

I'll report back if no one else confirms this.

HarrierAWD

The black L shape piece is just a connector. PCV valve is made of metal.

hitthepin

Thanks for clearing that up. So do both PCV connector and valve need to be replaced?

bob2200

The parts guy at the Lexus dealer came out to the car and checked the date of manufacturer on my '02. I don't know if this signifies anything.

There is no PVC piece on mine, a rubber hose fits over the metal PCV device.

The original PCV device rattled when shaken, so maybe it was still OK, after 46,000 miles.

Lexmex

Looking at that second design (not the one on mine) seems like that angle would shoot the gases slightly faster toward the intake than the design on my 99. I still like the 99 with PWR control on the tranny.

The PVC piece that is on mine (the plastic valve) should be replaced as it has a spring inside that can get corroded even with cleaning. What I like to do is shoot some carb cleaner (don't just shoot cleaner in there and put it back in) in there for a second, put it under water for a second or too, then I used computer keyboard cleaner though electric contacts cleaner works well, too. Then put it under water one more time. My uncle got upset once when I just shot WD-40 into it and was going to put it back in as the deposits can build up and water alone won't clear it out.

As to the other metal piece, I would see if it is clean on the inside. I assume one could clean it in a similar fashion to the valve itself.

You can stick a small screw driver in one end and feel the spring.

Lexmex

A closer look at the valve.

hitthepin

Lexmex, that piece was the part that I changed on my father's 99Rx300 as well.

So you're saying on your Rx you only have the plastic L-shape part?