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Temporary valve cover oil leak repair

Discussion in 'Boxers/TR/M' started by Ferrari Testarossa, Jul 10, 2011.

  1. Ferrari Testarossa

    Feb 27, 2011
    88
    Full Name:
    David Mason
    I did a cheap repair of an oil leak from a valve cover gasket.
    I had family on a short term visit from California and they all wanted rides in the TR.


    I started the TR and discovered an oil leak at the bottom of the valve cover corner where it meets with the bottom cam seal. Oil was dripping on to the exhaust making lots of smoke.
    Instead of ordering a new gasket, I decided to patch the area using a less common high temperature "Ultra Copper" silicone sealant. First I emptied a Windex sprayer and filled it with lacquer thinner. The lacquer thinner was sprayed on to the area of the oil leak and wiped dry. I repeated the cleaning several times and applied the silicone sealant around the outside of the gasket leak. The silicone cured for a day and I started the TR...The leak was gone! I took everyone out for rides and the silicone patch endured the heat of the spirited driving. I'm not sure how long it will last but at least the patch works. I ordered a new valve cover gasket in case the leak reoccurs.

    Years ago I fixed valve cover oil leaks with external silicone on my old Subaru wagon and it never leaked again for the years I had the car.

    I'm not suggesting we should deal with all oil leaks in this cheap manner but in some cases
    it can work.


    All the best,

    David
     
  2. blown daytona

    blown daytona Formula 3

    Feb 6, 2008
    1,607
    maryland
    if it does not start leaking in the next week, it will probably hold for a while. The key is what you did to prep the sealant. You got it 100% clean of oil before you put the sealant on.
     
  3. Ferrari Testarossa

    Feb 27, 2011
    88
    Full Name:
    David Mason
    Well the silicone patch on the bottom valve cover continues to seal the oil leak. I have driven about 200 miles since the repair and it has not leaked. I haven't tracked the TR but I have driven it on a few hot days with the water temperature in the 195 range. Now that I'm confident about the patch job, I have no incentive to install the replacement gasket I ordered ;-)
     
  4. Champboat/Champcar

    Champboat/Champcar Formula Junior

    Jan 29, 2007
    875
    Freeport NY
    Full Name:
    Eric T
    You can also try Honda -Bond , its a silicone gasket maker, I have used it and it blows everything else i used away .
     
  5. Ferrari Testarossa

    Feb 27, 2011
    88
    Full Name:
    David Mason

    I'll check it out...Thanks for the suggestion!

    So far the silicone valve cover patch is holding with about 300 spirited miles. It's a science project. If it holds up to the test of miles and time, some others may try this cheesy and cheap repair option.
     
  6. Philwozza

    Philwozza Formula 3

    Apr 23, 2009
    2,045
    Winchester UK
    Full Name:
    Phil Worrall
    I guess I may have done that before :D

    P
     
  7. Ferrari Testarossa

    Feb 27, 2011
    88
    Full Name:
    David Mason
    Update on the oil leak stopped with external silicone sealant:

    I have driven 2,500 miles since the oil leak repair. To date the external silicone sealant applied to the bottom half of the right cam/valve cover continues to seal in the oil with no leaks. It is surprising. I admit it does not look pretty when looking up from the underside. But you can't see the external silicone when looking down on the engine. ;-)

    The next time I get under the engine, I'm going to apply the sealant to the left side cover as preventative maintenance. I'm convinced this cheap and fast repair method has potential to become a more "permanent" solution when properly applied. Of course a professional mechanic would never recommend it or do it. I will continue to monitor the silicone patch. It's not likely the sealed oil leak will burst and erupt. I'm happy about the time and money saved.

    -David
     
  8. stremer

    stremer Rookie

    Jan 27, 2013
    29
    Rancho Santa Fe
    Full Name:
    John
    David

    I am curious how well the sealant has held up
     
  9. Ferrari Testarossa

    Feb 27, 2011
    88
    Full Name:
    David Mason
    Hi John, so far the silicone patch on the oil leak is holding well. I have driven about 8K miles since the repair back in 2011 and not a drop of oil on the repaired side. The driver's side now has a tiny leak but it's not dripping. I'll patch that side when needed. I also repaired an oil leak on the valve cover of my 951 with success and I plan on patching some leaks on my 911 oil return tubes.

    I would still caution the repair as a "permanent" solution. However, I have no incentive to address these oil leaks with the traditional method of spending lots of time cussing and removing/replacing gaskets. The silicone repair costs about $6 with 10 minutes surface clean up and two minutes appliciation. With the time and money saved you can celebrate with a glass of Cognac!
     
  10. SonomaRik

    SonomaRik F1 Veteran

    Dec 15, 2006
    6,694
    Sonoma, CA
    I really gotta ask: Are you going to just skip the replacement of the gasket and rely on this approach? Due to the length of time this has gone on, I'd of course expect your obvious answer as yes, but somehow this seems to bypass the better approach to replace the seal. I mean, am I missing something here as to pressure etc.?
     
  11. roadracer311

    roadracer311 Formula 3

    May 6, 2009
    2,350
    San Francisco
    Full Name:
    Paul
    Wow! This is very impressive! It seems that, similar to painting, the key is in the prep work, and getting everything dry dry dry, first.

    A friend of mine punched a 1cm x 2cm hole in the engine case of his motorcycle when his drive chain failed. I pronounced it a fatal blow when I saw it. But then realized that the bike was worth $500 not running or $4k running, I spent about 3 hours degreasing the thing, and then an hour with fuel tank putty, patching the hole. It has been good for about a year now.
     
  12. Ferrari Testarossa

    Feb 27, 2011
    88
    Full Name:
    David Mason
    For now I'm content with using the silicone patch. The original leak had occured with about 2K miles on the gaskets after a major service at the dealer by the previous owner. The silicone layer is about 1/4 to 1/3 inch thick and spead wide but it's on the underside and nobody can see it. I figure if it ever leaks again it would easy to remove the old patch and make a new one. It's surprising how well it works.

    I also resealed my outer CV boots on my 911 with Hi temp black silicon. I was replacing the shocks and noticed the boots were tearing. I didn't want to pull the axles as it's a PITA job on a '97 C4S. I cleaned the boot surface and did not see contamination of the bearings. I figured there was no down side of patching and seeing the results. Well 5K miles later the silicone is holding well and no CV bearing issues. If the patch fails here then it's time for new boots.
     
  13. Ferrari Testarossa

    Feb 27, 2011
    88
    Full Name:
    David Mason
    I had a '72 VW van and a rock punched a one inch hole in the crank case. I made an aluminum patch and gasket. I drilled some holes and placed the patch over the damaged area. It woked perfect and never leaked. Years later the magnesium block caught fire from a fuel leak; that van burned to the ground.
     
  14. 1974gt4

    1974gt4 Formula 3
    Owner

    Sep 19, 2009
    1,496
    in my garage...
    Full Name:
    Dr. Italiani
    another fan of JB weld here.
     
  15. V4NG0

    V4NG0 Karting
    Silver Subscribed

    Dec 14, 2018
    93
    Full Name:
    Vinny
    Bringing back this thread. Has anyone else tried this method for an oil leak and what were the results?
     
  16. MOSS

    MOSS Formula 3
    Rossa Subscribed Owner

    Apr 28, 2004
    1,211
    Remember it is a zero pressure area and oil just settles in that spot so I imagine you won't see it again.
     
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  17. V4NG0

    V4NG0 Karting
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    Dec 14, 2018
    93
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    Vinny
    In this case, it’s a cam seal leak. I’m particularly curious as to the applicability of this fix for that purpose. Oil drops are hitting the ground.
     
  18. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    14,763
    The Cold North
    Full Name:
    Tom
    Will not work for a cam seal leak. Replacment is the only way to fix that one..
     
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  19. V4NG0

    V4NG0 Karting
    Silver Subscribed

    Dec 14, 2018
    93
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    Vinny
    Can replacement be done with the engine in and is it difficult?
     
  20. turbo-joe

    turbo-joe F1 Veteran
    Silver Subscribed

    Apr 6, 2008
    5,639
    southwest germany
    Full Name:
    romano schwabel
    no
     
  21. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,552
    Which cam seal? On the rear, I see no reason why not....
     

    Attached Files:

  22. turbo-joe

    turbo-joe F1 Veteran
    Silver Subscribed

    Apr 6, 2008
    5,639
    southwest germany
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    romano schwabel
    you posted now a picture of the front, and this seal you can not change with engine inside the car


    why soo much hylomar?
     
  23. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,552
    As applied, the Hylomar is pushed out of the connection as the flange/o-ring is pushed into place. The Hylomar was placed on the male flange outboard of the o-ring and not in the female cylinder head. At the o-ring groove, a minimal amount of Hylomar lubricates the o-ring as it slides into place. A quick wipe cleans the exterior, leaves the joint full and no Hylomar is pushed into the engine.

    No leaks.

    Sliding a dry o-ring into that position may tear, or roll the o-ring.... leaks.

    you are right... the pic is the front intake. Can’t pull the cam belts to get at the seal with engine in. The rear distributors however can come off to expose the seal with the engine in.
     
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