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Leak down test results from PPI... Opinions?

Discussion in '348/355' started by B Feelgood, Sep 15, 2007.

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  1. B Feelgood

    B Feelgood Rookie

    Oct 16, 2005
    35
    Pittsburgh, PA
    Full Name:
    Brian
    #1 B Feelgood, Sep 15, 2007
    I had a PPI done today on a 1995 F355 with approximately 10,000 miles The test was done a warm motor and used the tool that threaded in with the spark plug removed. This car has the original bronze valve guides and exhaust manifolds. The results are as follows.

    #1- 10%
    #2- 10%
    #3- 10%
    #4- 12%
    #5- 8%
    #6- 8%
    #7- 8%
    #8- 8%

    The shop is an independent that works exclusively on Ferrari's. The mechanic who did the testing said the results were good and in line with that year/mileage/guides. He did not do a compression test because he was confident with those percentages. Now from what I have read on these forums, the general consensus seems to be that under 10% is acceptable and over 10% is excessive.

    Obviously this is a heavily opinionated question but do these results seem borderline high for this particular car?
     
  2. Shark01

    Shark01 F1 Veteran

    Jun 25, 2005
    6,484
    #2 Shark01, Sep 15, 2007
    These numbers are ok........and it helps that they are consistant.

    If this was the low point of the PPI, it looks like a thumbs up.
     
  3. No Doubt

    No Doubt Seven Time F1 World Champ

    May 21, 2005
    72,740
    Vegas+Alabama
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    Mr. Sideways
    #3 No Doubt, Sep 15, 2007
    10,000 miles is pretty low mileage, so you'd expect that the car would need to have a good Italian tune up (i.e. full RPM drive) to clean out any carbon or gunk that's gumming up the works a bit from doing so much sitting over the years.
     
  4. B Feelgood

    B Feelgood Rookie

    Oct 16, 2005
    35
    Pittsburgh, PA
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    Brian
    #4 B Feelgood, Sep 16, 2007
    To me that was the low point of the PPI, if you would even call that a low point. From the perspective of the mechanic who did the PPI everything else looked great. Paint was excellent, zero shrinkage, no bolster wear, top worked nice, OEM toolkit/books, no sticky pieces yet etc. As for future service, he said the brass valve guides would probably be worn to the point of needing replaced at around 30,000 miles (educated guess.) If I had never visited these forums I would have thought those results were fine. I then seen a few other members with similar cars (1995-1997 / 6k-12k miles) post leak down results of 2%-4% which makes my numbers seem high. Aaaahhhh what to do...
     
  5. SGM

    SGM F1 Rookie
    Owner Silver Subscribed

    Sep 27, 2006
    2,797
    Rockville, MD
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    Steve
    #5 SGM, Sep 16, 2007
    I looked at a 97 355 last year with low miles and the leakdown had numbers ranging from 4% to 48%. And I know of others that were as high as 60%. So I dont think yours is bad at all.
     
  6. ProCoach

    ProCoach F1 Veteran
    Owner

    Sep 15, 2004
    5,465
    VIR Raceway
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    Peter Krause
    #6 ProCoach, Sep 16, 2007
  7. No Doubt

    No Doubt Seven Time F1 World Champ

    May 21, 2005
    72,740
    Vegas+Alabama
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    Mr. Sideways
    #7 No Doubt, Sep 16, 2007
    It's not a hard or fast rule, but the inner cylinders tend to experience the 355's "burned valve," valve guide, and exhaust header issues first.

    Your leakdown above doesn't show the inner cylinders as being the leakiest, so that's a pretty good sign (along with the low leakdown percentages) that you are in good shape.

    More worrisome would have been a high leakdown number in any one or more of the inner cylinders #2, #3, #6, or #7.
     

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