PCV Valve Replacement with Pictures

why so often, bad gas?

 

i'll replace mine at the same time intake manifold is off for cleaning. 80,000-100,000 miles.

 

I'll wait until 120k miles, and then replace

• plugs
• PCV
• Struts

 

Why would the manifold be off around that millage?

S my Z987 ung talk

 

How do you know the PCV valve needs to be replaced?

 

Is it really the passenger side of the engine ?

 

it must be bad something, around here, they seem to go 150k+ with no pcv problems. maybe the heat or type of driving?

 

This would be a proactive move to clean the EGR valve, valve plumbing, and the intake manifold passages associated with the EGR system. The EGR system builds up carbon deposits over time which will eventually trigger a fault code.

The OP did not say that the PCV valve had failed. He replaced it as a preventive maintenance measure.

 

right, but for what reason?

 

1. During the normal operation of the gasoline engine, hydrocarbon gases resulting from gasoline combustion leak past the piston rings and enter the engine crankcase area. This is called "blow-by".
2. These gases build up pressure in the crankcase area. In the old days, 1950s and earlier, the engine was just vented to the outside which resulted in unnecessary air pollution.
3. Starting in the 1960s, the concept of "positive crankcase ventilation" was developed to take the HC fumes and direct them to the intake manifold so the engine would burn them as part of normal operations.
4. The PCV valve regulates the flow of these gases to the intake manifold, based upon the amount of engine vacuum that is developed under various operating conditions.
5. Since the PCV valve is exposed to the HC fumes, it develops HC deposits over time which will eventually inhibit proper valve operation. Hence the valve should be replaced periodically, I would say 100K miles is a good interval.
6. The OP mentioned shaking the valve and listening to the resultant rattle as a means to judge the valve's condition. A new valve has a very metallic rattle while a used valve has a muffled rattle or in very bad cases, no rattle at all, due to the HC deposit buildup. Another way to judge the valve's condition is to blow air through it. The air should easily pass in one direction but not in the other direction.
7. A plugged PCV valve may lead to engine oil seal leaks as the crankcase pressure builds up which forces engine oil past the crankshaft seals.

 

thanks patrick, any ideas as to why some might clog earlier than others? iow, is there anything we can do to prevent it or delay it?

 

I would say that those conditions leading to engine sludge buildup are probably the same conditions that would lead to the PCV valve clogging sooner vs. later. For example, very short trips are likely to develop sludge, where the engine oil does not have a chance to heat up and dissipate water vapor coming from condensation. That is why the engine oil needs to be changed at least annually, for vehicles that are seldom driven.

 

Maybe with muffled rattle it's still functional though?

OTOH, I hate all mention of EGR and clogging, seems like that's the perineal elephant in the room.

 

It is true that a valve with a muffled rattle is probably still working, but it is not as effective as a new valve in allowing the free flow of gases through it.

 

thanks again!

 

my apologies, if i hurt you in any way den, i was actually trying to learn something, not be sarcastic.

the truth is, i don't usually bother with those threads, because i don't keep my cars that long.

but when i saw your nice write up and pics, it made me curious to learn more.

 

RE third picture: I'm having orientation problems. Are you underneath the vehicle with the cover off, or on the top of the engine?