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    #1

    Compression and leakdown tests relating to oil loss.

    I did a compression test today to try and find out what I need to do about my oil issue(I'm going through a bunch), initially I had hoped valve seals would solve the problem but they did not.
    All cylinders read about the same at 140 with no big change between any of them, I have been told that my oil issue could be either valve guides or rings and of course guides will be less of a big deal since the motor won't have to be taken all apart and more problems found...
    I am trying to interpret results so far, what will a leakdown test tell me?
    I have a test kit but both of my compressors have decided to not work, so I gotta either fix one or get a new one in the next few days to use the tester.
    The motor had a turbo on it, it's a XXX block that was machined by a shop in PA and it's got AFR 185 heads with a CHP stroker kit.
    I also have the problem with coolant that appears to be coming out the head gasket on the passenger side, it is not going into the oil and oil is not going into the coolant.
    I only see oil smoke when I drive the car then park and restart it again within the hour.
    Any other tips to help me figure out if it's rings or guides for sure?
    1989 Country Squire - Twilight Blue, 347 stroker


    2005 Crown Victoria Sport - Black - Stainless Works full exhaust with Borla Pro XS mufflers, BBK 75mm TB, Accufab plenum, CVPI airbox, Heinous control arms, etc...
    Tags: None
    #2
    If you slip a little bit of oil into the cylinder after a compression test and retest, the pressure will climb if the rings are shot, not if the valves are bad. With all cylinders even I would say valves guides are your problem without even the oil test

    That said I have never learned about leakdown tests and how much more info they can provide.
    03 Marauder DPB, HS, 6disk, Organizer Mods> LED's in & Out, M&Z rear control arms, Oil deflector, U-Haul Trans Pan, Blue Fuzzy Dice
    02 SL500 Silver Arrow
    08 TC Signature Limited, HID's Mods>235/55-17 Z rated BFG G-Force Comp-2 A/S Plus, Addco 1" rear Sway, Posi Carrier, Compustar Remote Start, floor liners, trunk organizer, Two part Sun Visors, B&M Trans drain Plug, Winter=05 Mustang GT rims, Nokian Hakkapeliitta R-2 235/55-17
    12 Escape Limited V6 AWD, 225/65R17 Vredestein Quatrac Pro, Winter 235/70-16 Conti Viking Contact7 Mods>Beamtech LED headlight bulbs, Husky floor liners

    Comment

      #3
      Yeah, I didn't do the wet test because I didn't have any extra.
      I thought it's supposed to increase with oil added to the cylinder.
      1989 Country Squire - Twilight Blue, 347 stroker


      2005 Crown Victoria Sport - Black - Stainless Works full exhaust with Borla Pro XS mufflers, BBK 75mm TB, Accufab plenum, CVPI airbox, Heinous control arms, etc...

      Comment

        #4
        A leakdown test tells you if there's a leak in a valve or rings. It'll his out the intake if an intake valve leak. Out of the exhaust for an exhaust valve leak. And out the breather for rings. There should be some leakage for the rings since there's a gap, but since you have good compression, I would say that isn't an issue. The leakdown test is usually done when low compression is found to determine if it's top end, bottom end, or both. I would think that you may need an oil catch can on the PCV lines and the grommet for the PCV valve may need some ultrablack RTV to seal it to the intake if it's using a stock style PCV valve. The oil loss may be leaking out the PCV or being sucked up through it (which is why boosted applications use a catch can).

        Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
        rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
        Originally posted by gadget73
        ... and it should all work like magic and unicorns and stuff.
        Originally posted by dmccaig
        Overhead, some poor bastards are flying in airplanes.

        Comment

          #5
          Yes it is supposed to increase with oil if rings are bad. not so much if valves are bad. The idea being the oil will "seal" the rings.
          Sly has some good suggestions there.
          03 Marauder DPB, HS, 6disk, Organizer Mods> LED's in & Out, M&Z rear control arms, Oil deflector, U-Haul Trans Pan, Blue Fuzzy Dice
          02 SL500 Silver Arrow
          08 TC Signature Limited, HID's Mods>235/55-17 Z rated BFG G-Force Comp-2 A/S Plus, Addco 1" rear Sway, Posi Carrier, Compustar Remote Start, floor liners, trunk organizer, Two part Sun Visors, B&M Trans drain Plug, Winter=05 Mustang GT rims, Nokian Hakkapeliitta R-2 235/55-17
          12 Escape Limited V6 AWD, 225/65R17 Vredestein Quatrac Pro, Winter 235/70-16 Conti Viking Contact7 Mods>Beamtech LED headlight bulbs, Husky floor liners

          Comment

            #6
            What engine are we even talking about here? 4.6 or 5.0?

            If its the 302, have you checked for oil in the PCV line? It may be sucking the oil up there for whatever reason. Depending on the intake, it may just have a shitty baffle under the PCV valve.

            if it was the guides, new seals would actually bandaid that for a little while. If it made no difference I'm inclined to suspect its not the guides, assuming you used good seals. The umbrella may not do it, the later style ones that look more like a shaft seal with the metal band around it work very well though.
            Last edited by gadget73; 09-23-2017, 09:44 PM.
            86 Lincoln Town Car (Galactica).
            5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

            91 Lincoln Mark VII LSC grandpa spec white and cranberry

            1984 Lincoln Continental TurboDiesel - rolls coal

            Originally posted by phayzer5
            I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

            Comment

              #7
              Since it's in Box Tech... I figured the 302.

              Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
              rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
              Originally posted by gadget73
              ... and it should all work like magic and unicorns and stuff.
              Originally posted by dmccaig
              Overhead, some poor bastards are flying in airplanes.

              Comment

                #8
                Originally posted by gadget73 View Post
                What engine are we even talking about here? 4.6 or 5.0?
                Yeah, it's the 347 in the wagon.
                I used the AFR seals for these heads, viton with the spring seal. It seemed to get a little better but the last 2-3 months it's losing more.
                1989 Country Squire - Twilight Blue, 347 stroker


                2005 Crown Victoria Sport - Black - Stainless Works full exhaust with Borla Pro XS mufflers, BBK 75mm TB, Accufab plenum, CVPI airbox, Heinous control arms, etc...

                Comment

                  #9
                  Do you know it's burning the oil? Smoke out the tail pipes? Or do you just smell it (like a leak burning off the exhaust)?

                  Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
                  rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
                  Originally posted by gadget73
                  ... and it should all work like magic and unicorns and stuff.
                  Originally posted by dmccaig
                  Overhead, some poor bastards are flying in airplanes.

                  Comment

                    #10
                    One can have good compression but the oil rings can still be leaking.
                    Scars are tatoos of the fearless

                    Comment

                      #11
                      Originally posted by sly View Post
                      Do you know it's burning the oil? Smoke out the tail pipes? Or do you just smell it (like a leak burning off the exhaust)?
                      I only see it when I start the car after it's been sitting for a short time, I go to work at 4am so it's difficult to see anything if I might be smoking.
                      I have seen once or twice that I got a small cloud when I took off after making a turn
                      1989 Country Squire - Twilight Blue, 347 stroker


                      2005 Crown Victoria Sport - Black - Stainless Works full exhaust with Borla Pro XS mufflers, BBK 75mm TB, Accufab plenum, CVPI airbox, Heinous control arms, etc...

                      Comment

                        #12
                        Then yeah... probably oil rings like turbo said or the valve seals have ridden up on the stems and are no longer seated. I've heard that the ones that don't have the seat at the bottom for the spring to sit on will sometimes do that.

                        Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
                        rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
                        Originally posted by gadget73
                        ... and it should all work like magic and unicorns and stuff.
                        Originally posted by dmccaig
                        Overhead, some poor bastards are flying in airplanes.

                        Comment

                          #13
                          I'd still be making sure its not getting sucked through the PCV system before you go too far down this rabbit hole. Oil laying in the intake acts a lot like leaky valve seals.

                          Worn rings tend to smoke more on decel than after sitting. The oil isn't going to leak past the rings when it sits, but it will suck up past under high vacuum conditions.
                          86 Lincoln Town Car (Galactica).
                          5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                          91 Lincoln Mark VII LSC grandpa spec white and cranberry

                          1984 Lincoln Continental TurboDiesel - rolls coal

                          Originally posted by phayzer5
                          I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                          Comment

                            #14
                            I have a catch can on there and the sight tube on the side doesn't show anything really, I'll dig more into it this week.
                            1989 Country Squire - Twilight Blue, 347 stroker


                            2005 Crown Victoria Sport - Black - Stainless Works full exhaust with Borla Pro XS mufflers, BBK 75mm TB, Accufab plenum, CVPI airbox, Heinous control arms, etc...

                            Comment

                              #15
                              could be the filter under the PCV valve needs replaced or cleaned if it dosnt get damaged removing it
                              Scars are tatoos of the fearless

                              Comment

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