I screwed up. Any input on my engine issue?

  • #1

    I screwed up. Any input on my engine issue?

    sterday I set up the AEM FIC , added enough fuel to be nice and rich under boost, and retarded 1 degree of timing per lb of boost. Checked to see that the retard was working with my timing light.

    Then I slapped the turbo etc on and took it out for a test run to watch AFR. She was nice and rich under low boost, spooling and boosting at low rpm, BOV was working. Great.

    I got a little ahead of myself and did a WOT pull. Unbelievable power. I was at the top of 3th and she wouldn't stop gaining power, super excited. Unfortunately my wastegate didn't open. Last I saw I was going on 20lbs, it happened extremely fast from vacuum to 20lbs. I was too excited, Should have felt it out a little more and stopped right when she went over 10psi. I only put an 8psi spring in there lol. Then I smelled coolant

    Pulled over, upper rad hose popped right off the rad. Clamp was tight. Uh-oh, Cooling system must be getting pressurized with cylinder pressures. Opened cap, refilled her. With cap off, I went to crank and got a hydrolock sound. She was almost completely hydrolocked after 1 WOT pull. For every revolution the starter could turn the engine, the radiator was shooting water like a geyser. Stopped everything, hooked up the chain and towed her home. It was late so that was that.

    I've never had this happen before so this is new to me, and I would appreciate some input so that it's not all guess work when I pull the heads off to see if I can slap new head gaskets in and put it back together after fixing the wastegate issue

    I'm thinking before I buy any new head gaskets I need to pull the heads and inspect.

    Best case scenario I blew the head gasket, next best the head floated and the threads in the block are still good. Maybe the bolts stretched. I can work with that with new head bolts

    I doubt the head cracked but it's possible. If the the water jackets in the block have any damage I'm screwed.

    Now while I was fabricating all the turbo parts during the last few months I also regasketed the engine top to bottom. I used felpro head gaskets. Now if I can salvage this I'll go with MLS gaskets.

    Any input as to what I should look for and what you think happened? Thanks.
  • #2
    Felpro head gaskets are known for being inconsistent quality, and probably even more so at 20PSI. If you're lucky, the felpro gasket vented to the coolant and
    your coolant system was over pressurized and popped the hose because the 13psi safety poppet couldn't vent fast enough.

    Pretty straightforward really, pull heads and inspect for damage. Doubt you popped any block threads or snapped a head bolt but that'll be obvious
    during disassembly. You could check the break-torque of the bolts to see if they all crack loose at similar torque values relative to each-other.

    A good quality headgasket, without breaking the bank on MLS gaskets are Victor Reinz/mahle PN 5826, Rockauto is where i get mine. Supposedly they are OEM.

    Drain oil and inspect for coolant, change oil and start it once it's reassembled then maybe change it once more if you found coolant on the first change
    just to be on the safe side if any coolant saw bearings.


    84 AE/Shiro #683/Shiro #820/84 Turbo
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  • #3
    I'd pull the plugs and get the coolant out of the cylinder(s) if you think it was hydro locked. Then spray some WD-40 down in them, unless you are pulling it apart right away.