2005 GMC PCV Valve 5.3L

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139
Location
Arkansas
Thread starter
I have a 2005 GMC Sierra 1500 with the 5.3 engine. I need to replace the PCV valve because it is sticking open and pulling oil out of the engine. The PCV valve is made into the valve cover, so the entire valve cover($150) must be replaced to fix the PCV valve. Are there any other options? Thank you for your time and advice.
 
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19,479
Location
Chicago Area
You could try cleaning it with spray carb cleaner. But they are normally open when running anyways. I have no idea what is going on with your car.
 
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169
Location
Ontario Canada
...there really isn't a PCV Valve. It is a fixed orifice. No moving parts... Maybe something has happened to the baffle in the valve cover?
 
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2,620
Location
High Tax Illinois
Does this engine have MDS? If it does GM has had problems with the shut down cylinders sucking oil past the rings. Check with GM dealer for TSB for this problem.
 
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Messages
139
Location
Arkansas
Thread starter
I have an oil consumption problem. A dealership, that I trust, told me they have replaced the left side valve cover, that contains the pvc apparatus, in several vehicles with a similar oil consumption problem and it fixed the problem. I am thinking about installing an inline PCV valve in the vacuum line that goes to the valve cover instead of replacing the whole valve cover. Would that cause any problems?
 
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19,677
Location
Sunny Florida
Originally Posted By: Gotch
...there really isn't a PCV Valve. It is a fixed orifice. No moving parts... Maybe something has happened to the baffle in the valve cover?
You do not need new parts! Just remove and clean everything, this commonly plugs up with crud.
 
Messages
139
Location
Arkansas
Thread starter
HOT DOG!!! I can do that! This is a completely different kind of PCV arrangement than I have ever seen before, and I did not know exactly what was there. Removing and cleaning will only cost me a little time. If it does not fix the problem, then I can try something else. THANKS!
 
Messages
185
Location
Illinois
If I remember right, GM has made a revised valve cover with a slightly different PCV/baffle for those engines. You can try cleaning it and see what happens, but if it doesn't fix it, I believe there is still hope.
 
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998
Location
Lexington, SC
What is MDS? I don't think GM calls it MDS. The feature I think you are referring to is GM's AFM , I don't think you can buy a 5.3L GMC Sierra, Silverado, Yukon, or Tahoe without AFM.
 
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19,677
Location
Sunny Florida
Originally Posted By: Jim Spahr
What is MDS? I don't think GM calls it MDS. The feature I think you are referring to is GM's AFM , I don't think you can buy a 5.3L GMC Sierra, Silverado, Yukon, or Tahoe without AFM.
Jim, MDS is a Chrysler acronym for Multi Displacement System. It gets used when describing almost every car that cuts out cylinders during light load operation.
 
Messages
3,258
Location
Indiana
Originally Posted By: The_Jake
If it is slipping out try some gorilla glue on it and allow to dry overnight in your garage. Don't use too much as that stuff expands 3x.
what are you talking about ????? glue ??? this truck has a non-removeable PCV setup.
 
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3,561
Location
Central Iowa
The AFM (automated fuel management) setup on many GM engines that causes the engine to go to 4 cylinder mode when less power is needed has caused a plethora of oil consumption problems. Supposedly, this problem got resolved with the late 2011 engines on, but time will tell. Many, like me, have effectively disabled the AFM from ever going to 4 cylinders. The engine remains in 8 cylinder mode all the time. Now, to the oil problem getting into the intake from the PCV system. Simple. Most, if not all, folks should consider installing an oil catch can in the PCV line from the PCV valve/fitting and the intake manifold. This will filter out any oil that normally is drawn up with the crankcase gasses. This oil can reduce power, in that the ECM has to compensate and sometimes resort to low octane settings in the ECM. Also, this oil will coat the inside of intake manifold, add the EGR exhaust gasses coming in, and you have a recipe for serious crud. And some of this will coat throttle bodies and valves. All in all, just a bad situation just waiting to happen. These oil separators are relatively inexpensive and not difficult to plumb into the PCV line. I just purchased a 2013 Silverado with 5.3L and an oil separator will be going on within the next few weeks.
 
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