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Catch can full?

Discussion in 'SVT Shelby GT500' started by 70SCJ, Aug 28, 2019.

  1. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    After a few fairly short drives my passenger catch can is almost full. I'm thinking I have a big problem. No visible smoke or smoky smell.
    Built/camm'd motor with pretty well most bolt-ons including a low vac bypass valve. Running about 14lbs boost on E-85 and about 6K miles. Motor has not been beat on, but had a problem a few weeks back with some misfiring which was found to be loose connections with my Vampire anti-knock system and my coils. Plugs were wet when I pulled them.
    I had the SC off a few months ago to get the injectors cleaned and I'm wondering if I hooked something up wrong or did the misfires with the extra fuel wash down the cylinders?
    Help appreciated.
    70
     
  2. Mpoitrast87

    Mpoitrast87 Well-Known Member Established Member

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    Everyone will say do a compression/leakdown test. so Id do that first and report your findings.
     
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  3. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    That's in the plan.
     
  4. Race Red Boss

    Race Red Boss Active Member Established Member

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    Roger that on the big problem. No way your catch can should be getting that much oil so fast. Hope it isn't something serious. Good luck.
     
  5. serickson1

    serickson1 sericksonGT500 Established Member

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    What is in the catch can??.....E-85, Oil, or both?
     
  6. RBB

    RBB Well-Known Member Established Member

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    As others have stated, if your catch can is full after a few short drives you've got a big problem. That said, I've noticed I have more blow by and my separator fills faster on my built/cammed motor. Nothing like what you're seeing, though, I can still go quite some time before emptying it. Let us know how the compression/leakdown test turns out.
     
  7. Snoopy49

    Snoopy49 Well-Known Member Established Member

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    Have you checked your engine oil for E85 contamination?
     
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  8. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    Smells like oil only. Might have a hint of E-85.

    Did a compression test last night and every cylinder came back with 5% of one another. I'll do a leak down test as soon as I pick up a tester.
     
  9. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    I haven't tested it yet, but I'll put that on the list of things to do.
     
  10. biminiLX

    biminiLX never stock Established Member

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    Good news on the compression check.
    You mentioned plugs were wet, did you replace them?
    What do they look like now?
    Do you have a bore scope?
    Who built the engine?
    I’d recommend a used oil analysis.
    Good luck.
    -J
     
  11. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    I have not replaced the plugs. During the compression test they looked pretty good. Kinda grayish, but dry.
    If I locate a problem during the leakdown I'll take it in for scope and I'll draw an oil sample and send it off.

    The shop I use in St. Louis has an outside engine builder they use. Pretty reputable I believe.
     
  12. Catmonkey

    Catmonkey I Void Warranties! Premium Member Established Member

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    How many miles had you accumulated since the last time you drained the catch can?
     
  13. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    A couple hundred, maybe.
     
  14. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    More info, but not many answers. I did a leak down test and came up with the following results.
    Cyl 1 8% Cyl 5 15%
    2 10% 6 8%
    3 13% 7 8%
    4 7% 8 7%

    Compresson:
    1- 185psi 5- 187psi
    2- 185psi 6- 182psi
    3- 180psi 7- 185psi
    4- 190psi 8- 182psi

    I could hear a very faint air leakage in the exhaust with a stethescope and more pronounced when I stuck the stethoscope down the hole next to the leak down tube.
    Am I screwed?
     
  15. me32

    me32 BEASTLY SHELBY GT500 TVS Established Member

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    How aggressive are the cams? How is the vacuum?
     
  16. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    Cams are MMR Stage 3's. Vacuum is about -6 to -7 inches at idle. On decal in might run to -11.

    More info. I had switched catch cans a few months back when the Sheby snake engraved was offered by I believe JLT. It catches much more than my old Watts unit, which only showed a small bit in the cup.
     
  17. lexustech48

    lexustech48 RIP FoMoCo 1903-2014 Premium Member Established Member

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    Stupid question here, but maybe your PCV valve is bad?
     
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  18. 70SCJ

    70SCJ (Ret) USMC F/A-18 Driver Established Member

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    Is there a way to check it or just replace and move on?
     
  19. fullboogie

    fullboogie Well-Known Member Established Member

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    That's a damn good suggestion. I hadn't thought of that either.
     
  20. lexustech48

    lexustech48 RIP FoMoCo 1903-2014 Premium Member Established Member

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    Id replace it and move on. Traditionally, the idea is that you remove from Valve Cover and shake it. If it rattles its not concretely failed, but may not be operating optimally.

    Since our PCVs are electrically heated to regulate its temp, the heater element may have failed. Check to make sure you have voltage and ground on the harness side.

    Not to say perhaps you dont have another issue going on, but the PCV valve is an often overlooked maintenance part. Considering how cheap it is, Id try a new one and recheck for oil in your separator.
     

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