1HZ head gaskets not sealing

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Joined
Jan 23, 2014
Threads
2
Messages
8
Location
australia
gday blokes.

I have a hzj75 that popped the head gasket at the oil gallery at rear at 470k km. So I replaced the head gasket but when I drove up to 100kmh the temperature started to slowly climb, it got up to 110 degrees and stayed there. I took it back home and there was combustion gas spewing out the reservoir really badly. I took the head back off, sent it to an engine shop to get crack tested, milled flat and some other stuff and it came back all good. I put the vehicle back together and it seemed perfect. I took it up to 100kmh again and it overheated - no matter what it just sat at 110 degrees even in the drive way idle. There was a small leak of combustion gas into the coolant again as I noticed bubbles occurring at the rad cap but it wasn't big bubbles or lots and lots of gas spewing out but it was definitely leaking.

I pulled the head back off this afternoon and have ordered a genuine toyota gasket this time.

head bolts were replaced, followed the instructions that came with them that are different to toyota FSM, sought clarity and was told to follow instructions on the bolts

no contaminants in oil, no unburnt diesel from exhaust or gas coming from rocker cover

stuff about engine:
Gturbo @ 18.5psi
Intercooled
After market EGT(pre turbo)/oil pressure/water temp gauges
New radiator, fan, viscous clutch, waterpump and radiator cap
Tested thermostat allg (40k km old)
new fuel pump with correct timing, not wound up
EGT not going above 400
replaced with #5 gaskets

help me team
 
We try and keep all the diesel stuff on the diesel forum. Makes it easier to find things.
 
Ok.
1. Only use a genuine head gasket. Aftermarket ones are known for not sealing.
2. Check the head and block for warpage. Check with a machined straight edge and feeler gauges. 0.0079" limit.
3. Torque is 69Nm ,+90*, +90*. 3 stages. Threads lightly oiled.

All the rest sounds good. 18.5 psi won't hurt it.
 
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