I had wondered why my times at the track were .3 to .5 slower since my record run of Jan. 20 and I finally determined the culprit yesterday. Every two weeks, I check the PCV valve to see that it is not clogged. It hardly moved when I checked it yesterday afternoon, and after comparing it with one that I last used in July 2004, I realized its movement was seriously restricted. After replacing it with the old, still functioning valve, my times were back to what they used to be and the oil was a lot cooler.

I added the attached picture to show the location of the valve. As I recall, this is a very inexpensive piece. We have had a few discussions before, but the pictures were not of an RX300...this is.

 

A picture of the valve out of the socket.

 

Great info

 

The importance of the PCV Valve (from http://autorepair.about.com/cs/gener.../bldef_621.htm)

"The Positive Crankcase Ventilation valve is an emissions control device that routes unburned crankcase blowby gases back into the intake manifold where they can be reburned. The PCV system is one of the oldest emission control devices, and also one of the most beneficial. Besides totally eliminating crankcase emissions as a source of air pollution, the constant recirculation of air through the crankcase helps remove moisture which otherwise would cause sludge to form. Thus the PCV valve extends the life of the oil and engine. The PCV valve requires little maintenance. The valve and filter should be replaced somewhere around 30,000 to 50,000 miles (see the vehicle owners manual for service intervals)."

 

Lex, great information, checked my ~30k service and they did not change the PCB valve. I will ask about it at next service. It looks pretty simple, is it cleanable?

 

I blew air into it and it would not budge to easily. Even water had a hard time. Do not throw any type of petroleum substance in there. I tried some dish washing liquid (since I knew the thing valve was finished anyway and that freed it up a little more).

A good test is to pull it out and shake it to see if you hear anything. In addition, one can take a small screwdriver and insert it very carefully (as shown in the picture) to see if there if there is any spring inside.

 

Hey Lexmex,

just curious as to why no petrolium products?

Only in extreme cases have I replaced the PCV valve, most of the time I just remove it and spray wd40 into it and then drain it and re-install.

Figured if there is a spring in it then wd40 should help lubricate it and remove gunk at the same time.

I do this about every other oil change, and no its not because of the cost of a new pcv valve since its peanuts, more for the practicality of it.

 

It is mentioned in the service manual and my uncle said it is a no-no. I remember the day I did exactly what you did with some WD-40 and he grabbed it right out of my hand. He said that deposits can build up in there no matter how much you wash it out afterwards.

I can get virtually the same PCV piece, so for the price, I just end up replacing it.

 

I have not tried it, but there is supposidly a simple test ... The engine cover may interfere with the test.

remove the oil filler cap.
place a sheet of flat paper over the inlet and observe the vaccum being formed ... flat paper cups inwards.

Caution:
Watch out for oils slosh throught the removed cap and keep fingers/hands out of moving parts. Certainly dont drop things inside the inlet (other than the engine oil).


Salim

 

I might try this tonight.

BTW, if I ever get up to San Antonio will try to stop up in Austin.

 

If you do, drop bye, you have a friend here. PM first.
[let see if it will coinside with when my wife asks me to clean the stable .. RX, GS & SC with lots of clutter (poop)

Salim

 

I know what you mean. I just cleaned out my barn (storage shed in my apartment building) of all the poop for the RX.

I wanted to stop by a track in Texas to get in some runs and see Austin. Not sure when I will have the chance.

 

This morning I also checkd the hose to which the PCV Valve is attached to, but after blowing through it and cleaning it out with a little soap, I found no buildup of any kind.