+ Reply to Thread
Results 1 to 8 of 8
  1. #1
    Registered Member
    Location
    hilton head, SC, United States
    Member No: 72641 tricked is an unknown quantity at this point tricked's Avatar
    Join Date
    Apr 2003
    Posts
    29
    Rep Power
    0


    Yes | No

    excessive pressure blowing coolant via cap

    Car runs great!, no fouled spark plugs, great compression,no white smoke from tailpipe. however, whenever I boost the engine (10 p.s.i) EXCESSIVE PRESSURE BUILDS UP IN THE COOLANT HOLDING TANK AND BLOWS COOLANT OUT OF THE CAP! I've replaced the thermostat, with a 70, bought a new cap 16psi, don't know what else to do any suggestions? KURT


  2. #2
    davide30
    Guest
    Location
    , ,
    Member No: davide30's Avatar


    Yes | No

    so what you think about that

    About the Apexi S-AFC , it's a piggyback fuel computer , they work good on bimmer ??? or experience with that computer ???

  3. #3
    Michel.
    Guest
    Location
    , ,
    Member No: Michel.'s Avatar


    Yes | No

    Re: excessive pressure blowing coolant via cap

    It looks like a bad head gasket. Combustion chamber pressure is blowing into the coolent circuit.
    A gasket with a firering (I don't know if they exist for Bimmers) would seal better.

  4. #4
    Registered Member
    Location
    hilton head, SC, United States
    Member No: 72641 tricked is an unknown quantity at this point tricked's Avatar
    Join Date
    Apr 2003
    Posts
    29
    Rep Power
    0


    Yes | No

    Re: excessive pressure blowing coolant via cap

    How can the head gasket be blown if compression is still perfect and there is no evidence of fouled plugs or smoke blown is blown right?

  5. #5
    Registered Member
    Location
    Spencer, MA, United States
    Member No: 12259 Boru635 is an unknown quantity at this point Boru635's Avatar
    Join Date
    Jul 2001
    Posts
    1,800
    Rep Power
    0


    Yes | No

    It only happens when you\'re under boost so >>>

    the increased cylinder pressure, while under boost, is squeezing past the gasket. Under normal driving conditions or when testing the compression the cylinder pressure isn't high enough cause the gasket to leak.

    Sweeney

  6. #6
    Registered Member
    Location
    hilton head, SC, United States
    Member No: 72641 tricked is an unknown quantity at this point tricked's Avatar
    Join Date
    Apr 2003
    Posts
    29
    Rep Power
    0


    Yes | No

    Re: It only happens when you\'re under boost so >>>

    Thanx for the input! I just replaced this gasket 2 months ago, do you think I should re-torque the head? Or Take the head off have it pressure tested and then re-install? It's discouraging, I've just completely re-built the entire engine and turbo 6 months ago, didn't realize the fuel pressure regulator was missing and burnt up the first head gasket. Kurt

  7. #7
    Turbo_Bimmer
    Guest
    Location
    , ,
    Member No: Turbo_Bimmer's Avatar


    Yes | No

    Re: It only happens when you\'re under boost so >>>

    I don't know if BMW 'torque 'n yield' bolts used on the head are marginal for forced induction, but last summer, I drove the whole summer with my turbo at 6 psi with no problem. Then, in september, I did a 2 day DE, which was most of the time full throtle and full boost. When I came back of the event, my coolant level was a bit low, about 2-3 cup. After a fast inspection, I found some traces of dried coolant on the side of the engine block.
    The head gasket was only 2 year old (did the profile gasket), and the head bolts were also new BMW, of course.

    This winter I'm installing a copper head gasket with ARP studs, and the head has been o-ringed. Many people that I talked to said that torque and yield bolts were not the best thing for a blown application, and studs should be used.

    Michel.

  8. #8
    Registered Member
    Location
    hilton head, SC, United States
    Member No: 72641 tricked is an unknown quantity at this point tricked's Avatar
    Join Date
    Apr 2003
    Posts
    29
    Rep Power
    0


    Yes | No

    true that!>>>

    Actually I re-torqued my head slightly over specs well about 75 'lbs, but it was that or have to tear it all apart again. I've taken her over 6000 in 1st 2nd and third no problem no broken head bolts-Whew no coolant leaks the gasket was only two months old!

+ Reply to Thread


Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

     

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
1e2 Forum