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  1. #11

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    The PCV valve, hose and grommet are GM replacements. The hose and fixed orfice valve came as an assembly. I will dissconnect the valve from the hose and see if the vaccuum increases, if so, I will put the old style pcv valve back in and see if it makes a difference with fuel mileage. Thanks for all the responses j cat.

  2. #12
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    what is the part number of this new pcv fixed orifice /HOSE valve ? I WOULD LKE TO CHECK THIS PART OUT .

    I just replace the pcv and if needed get new hose like oem 2000 . use ac delco pcv .

  3. #13

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    Engine Crankcase Ventilation #12574660 GM. It comes with the fixed orfice valve and tube. I found Ebay to be the cheapest.

  4. #14
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    the part number is correct so just make sure that the intake connection is with no restrictions. also pvc tube may have some debris packing material in it.

  5. #15

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    The vaccum is low with the fixed orfice valve on it. I pulled the valve off with the engine running and it had really good vacuum, so I put the original style AC Delco valve back in it and there was still good vacuum. I just filled up my tank and only got 14.1mpg's this last tank. Will see if changing the pcv valve back to the original helps with the fuel mileage.

  6. #16
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    ya 14 mpg is not good. up here I get 17 MPG in the cold winter temps. you should get in 70 deg f temps 17-18 mpg if you keep the speed down to 70MPH.

    after the test run post back what happened.

    I have never seen this vac restrictor on any vehicle . the hose is with no internal valves.

    I am going to see if I can get one to look at .

  7. #17

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    The pcv valve is from a TSB that GM sent out for motors that are using too much oil during their oil change interval and it's supposed to slow consumption. I think its mainly for the AFM motors though, but figured I would try and see if my oil consumption would completely go away even though I am only using a quart about every 4,000-5,000 miles. The valve is hollow inside with a small hole in the end that goes into the valve cover.

  8. #18
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    well we are lucky we do not own those AFM engines. I too go about 8,ooomi on oil change synthetic mobil 1 and I use less than a qt of oil with 140,ooomi on it now. I would say 3/4 qt @ 8,ooomi. those new engines suck up lots of oil some with 40,ooomi use 1 qt every 1,000mi.

    thats why I still have this 2000 sil. new ones are not good !

    if the engines have alot of blowby gases reducing the PCV flow will reduce oil useage BUT it will create lots of carbon issues and plug fouling/oil damage. these engines also require dexos GM approved engine oils. my last oil change the mobil 1 has this now on the container.

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