Was changing my clutch and I noticed there appears to be coolant seeping between the cylinder head and the block at the back of the head. Also along the exhaust side as well. I've just put a new reconditioned head on, and has only had about 30 minutes driving time. The engine seems to run well, good power. I can't see the heater hoses or the heater outlet on the head leaking.

 

• Cylinder head surface was freshly machined, and I was pretty thorough cleaning the surface of the engine block, with sanding, vacuuming, and wiping it clean with metho.
  

• I did reuse the head bolts. I cleaned them up and they looked to be in good condition. I cleaned out the bolt holes in the block. And I lubricated the threads and under the head bolts.
  

• I've used a Permaseal head gasket, and have torqued to the specifications sheet that came with the gasket in the correct sequence.
  

Part number AJ670 (Nm)

3 stages: 54, 75, 87

• I used a Kincrome torque wrench and checked the torque like 5 times. Even let it sit for a week and came back and re-torqued
  

I did put a head on a 4K over a year ago and it has been going well with no leaks.

What could I try? New Toyota head bolts or ARP, different brand head gasket?

 

I did speak to an engine builder, and he said when running a new engine or an engine with a new head gasket, water should be used instead of coolant. Run it for a while and re-torque. Because the coolant can penetrate into the gasket and react with the gasket material before it can set properly.

I reckon clean the green and run it for a week or two, reinspect and re-torque - assuming you're not losing heaps of coolant and there's no coolant in your sump and there's no bubbles in your radiator while the engine is running.