coolant leaking in combustion chamber

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Thread: coolant leaking in combustion chamber

  1. #1

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    coolant leaking in combustion chamber

    like the title says im got a massive coolant leaking into the engine. the engine didnt over heat i was watching it the whole time.

    2 years ago i have done a HKS metal headgasket and ARP studs as preventive maintenance turns out the last owner already did it prior to me doing it but had bolts. I was driving on the highway and went to pass someone and hit 18psi (usual) and then coasted till i got off the freeway. then i noticed that it was running as if a spark plug came off (no power from idle to about 3k rpms) but white smoke coming from exhaust. drove from idle into higher rpms then when boost starts to kick in ran completely normal. ive checked the plugs and they are steamed cleaned. pulled the engine out and decided to pull the head thinking it was the head gasket but after i took the head off found that the gasket is 100% good no issues found there. but how did i get coolant into all 6 cylinders? i dont have coolant running thru my throttle body. i cleaned the head no cracks. checked the block also no cracks. is my hks turbo blowning coolant into the intake? i removed the turbo and checked but looks good. has anybody else ran into this problem?

    mods are
    HKS sport turbo upgrade
    HKS sport intercooler
    HKS 3000 pipe
    HKS evc-s
    lexus afm
    550cc injectors
    3inch turbo back exhaust w/test pipe
    3row radiator
    87 n/a hardtop auto-sold
    91 n/a-t sunroof 5speed-sold
    90 turbo targa 5speed

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  3. #2
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    you should have checked the torque of the studs.
    also did you use the supplied ARP lube when torqueing the studs down?

    This would happen if at ANY time the aluminum was annealed (ie overheated). Yes I mean anytime throughout the life of that aluminum head.

    The other problem might be detonation due to too aggressive timing or just not good fuel.
    Back in the supra game! 89..pics to follow shortly
    Into taking care of paint on cars. Enjoy all vehicles.

  4. #3

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    Actually i did they were all torqued correctly and i did use the lube supplied by ARP
    i redid the timing again about a month before this happened. it was put to oem standards

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  6. #4
    7M Fanatic sixpack's Avatar
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    What Figgie about the head fasteners when you pulled the head, were any of them loose ?
    Maybe a warped head.
    Post pictures of the head, block, and gasket surfaces, if you didn't clean them already.

    You need to approach engine failure problems like a crime scene investigator,
    don't wipe the finger prints off the murder weapon when you first get there

    And read Quake's thread on the cure for 7M heads coming loose:
    https://www.supraforums.com/forum/sh...sue&highlight=

  7. #5

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    no none of the fasteners were loose. right I did check the block and head as well as gasket before cleaning anything. I didn't of ever take pictures of it but I will take pics of the block and gasket just to be sure I didn't over look anything.
    the head and block were machined before install of new gasket.

  8. #6
    90T 3p141592654's Avatar
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    If its a cometic MHG then maybe the rivet that interferes with the head was not removed. Or maybe the timing cover was not machined with the block. Although both of those problems usually results in a big oil leak up front so probbaly not the case here.

  9. #7

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    Quote Originally Posted by supralip View Post
    it was put to oem standards
    if you torqued it to OEM specs, then there is your problem. OEM torque = too low for ARP.

  10. #8
    7M Fanatic sixpack's Avatar
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    Too low for a stock engine and bolts also.
    The root cause for the 7M's bad head gasket reputation.
    Mistake early on, so they were assembled wrong at the factory, and service manuals were printed wrong.

  11. #9
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    90 ft lbs for MLS + ARP studs (using supplied ARP lube).
    Last edited by Hybridau; 04-28-2019 at 04:04 AM.

  12. #10

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    Quote Originally Posted by CFTISupra View Post
    if you torqued it to OEM specs, then there is your problem. OEM torque = too low for ARP.
    no timing set to oem 10-12*
    head studs torqued to 90ftlbs with ARP lube
    Last edited by supralip; 04-29-2019 at 07:25 AM.

  13. #11

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    In order to use a stacked metal head gasket, both upper and lower surfaces need to be highly polished and absolutely flat for a proper seal. In my case, I had the block resurfaced and used a 0.020" metal shim gasket on top of the block sprayed with permatex copper and a standard Toyota gasket on top of that torqued down to 90 foot-pounds with ARP stud nuts. I needed a shim gasket to add back the metal that was taken from resurfacing the head and the block. Toyota only allows 0.010" from standard.

  14. #12
    7M Fanatic sixpack's Avatar
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    There is that .020" shim claim again....
    Have a link yet ?

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