Pcv
12-15-2008, 08:06 AM
#1
Senior Moderator
Thread Starter
Pcv
Changed the PCV on the RDX yesterday (had to order the part from the US, according to my dealer there is no stock in all of Canada 
and they said some crap about it being lifetime and not needing to change it bla bla what ever)
Just some advice, its in such a tight spot, it is suggested that you remove the coolant reservoir (its just one clip) to gain access get to the pcv and easily remove it.
image courtesy of someone on this forum lol (did a google image search)
and they said some crap about it being lifetime and not needing to change it bla bla what ever)Just some advice, its in such a tight spot, it is suggested that you remove the coolant reservoir (its just one clip) to gain access get to the pcv and easily remove it.
image courtesy of someone on this forum lol (did a google image search)
09-18-2010, 12:33 PM
#5
Intermediate
Click below for details on what a Positive Crankcase Ventilation valve (PCV valve) does.
http://en.wikipedia.org/wiki/PCV_valve
http://en.wikipedia.org/wiki/PCV_valve
09-20-2010, 12:04 PM
#6
Copy cat shinobi
What is a PCV, it's a valve that is hooked to Intake manifold and is a vacuum line, for the purpose of venting exhaust gases from the engine block.
During combustion the engine evacuates the exhaust out the exhaust manifold, allmost all the gases leave this route but some make their way into the block/ crank-case. The pressure will build so this needs to be vented somehow, PCV.
All manufactures today conform to emmissions, since these gases in the case are exhaust they cannot be released into the atmosphere. Those gases have to pass thru a catalytic converter, by re-intoducing it thru the intake manifold.
The downside of recycling exhaust (EGR & PCV) is that it does not aid in the combustion of air and fuel. It hampers the mixing, and raises the combustion temperatures.
The only reason to change a PCV if one has a crack in it and there is no required mileage. Just when it becomes unserviceble, like in this case.
Symptoms are a vacuum leak sound and found buy listening.(shhhh sound, and not turbo spool) Note that at any vacuum port the damaged line will pull in road debris and either clog or follow to the IM then into the cylinders.
Causes are most likely Gremlins, they climb in the engine bay at night while it's parked outside and chew on rubber.
There is a way to circumvent this, shortly I'll open a few performance threads, God and wife willing.
During combustion the engine evacuates the exhaust out the exhaust manifold, allmost all the gases leave this route but some make their way into the block/ crank-case. The pressure will build so this needs to be vented somehow, PCV.
All manufactures today conform to emmissions, since these gases in the case are exhaust they cannot be released into the atmosphere. Those gases have to pass thru a catalytic converter, by re-intoducing it thru the intake manifold.
The downside of recycling exhaust (EGR & PCV) is that it does not aid in the combustion of air and fuel. It hampers the mixing, and raises the combustion temperatures.
The only reason to change a PCV if one has a crack in it and there is no required mileage. Just when it becomes unserviceble, like in this case.
Symptoms are a vacuum leak sound and found buy listening.(shhhh sound, and not turbo spool) Note that at any vacuum port the damaged line will pull in road debris and either clog or follow to the IM then into the cylinders.
Causes are most likely Gremlins, they climb in the engine bay at night while it's parked outside and chew on rubber.
There is a way to circumvent this, shortly I'll open a few performance threads, God and wife willing.
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Lpf3420 (06-15-2011)
06-27-2013, 01:38 AM
#7
Thanks for this post - I changed my PCV at 4 years and 36K miles, mostly just to see if there was any build up. The input end was just damp, the output end seemed also slightly damp, but inside the rubber hose was dry.
Not to persuade anyone else - but for myself, I find it difficult to use the full 30 ft-lb torque required for the steel PCV threads, into aluminum. I just do not want to strip any threads.
I have noticed that how smoothly the PCV (or any bolt) torques down, depends upon whether the bolt is dry or oiled. If the washer and bolt threads are dry, then the PCV washer galls, and *sticks*. That cannot possibly produce an accurate torque.
So I placed a drop of clean oil on both sides of the *new* aluminum sealing washer, and on the PCV threads (after wiping clean). The oil provides some lubrication, so I reduced the applied torque. So I torqued the PCV to 250 in-lbs (21 ft-lbs).
I am not concerned about the PCV loosening, the hose and clamp will likely prevent that. But to make checking easy, I marked a line on the PCV and the part into which it is screwed, using red fingernail polish. Then each time I check the engine oil level, a quick glance tells me if the PCV has moved. I also marked all of the other easily accesible bolts/ nuts under the hood.
A last comment: I would *never* reduce the torque of a load bearing bolt or nut, but only when the fastener is just plugging a hole (drain plug - with safety wire), or as in this case of the PCV just sealing a vacuum hose.
JMO
Not to persuade anyone else - but for myself, I find it difficult to use the full 30 ft-lb torque required for the steel PCV threads, into aluminum. I just do not want to strip any threads.
I have noticed that how smoothly the PCV (or any bolt) torques down, depends upon whether the bolt is dry or oiled. If the washer and bolt threads are dry, then the PCV washer galls, and *sticks*. That cannot possibly produce an accurate torque.
So I placed a drop of clean oil on both sides of the *new* aluminum sealing washer, and on the PCV threads (after wiping clean). The oil provides some lubrication, so I reduced the applied torque. So I torqued the PCV to 250 in-lbs (21 ft-lbs).
I am not concerned about the PCV loosening, the hose and clamp will likely prevent that. But to make checking easy, I marked a line on the PCV and the part into which it is screwed, using red fingernail polish. Then each time I check the engine oil level, a quick glance tells me if the PCV has moved. I also marked all of the other easily accesible bolts/ nuts under the hood.
A last comment: I would *never* reduce the torque of a load bearing bolt or nut, but only when the fastener is just plugging a hole (drain plug - with safety wire), or as in this case of the PCV just sealing a vacuum hose.
JMO
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