The head gasket on my 8 is leaking oil externally. Compression and leak down tests were good and there is no signs of oil/coolant contamination or combustion leaking into coolant or oil. I studded the head a number of years back with ARPs using the one by one method and leaving the head on the block. I’m assuming this leak is a side effect of that.

I plan to replace the head gasket this winter to stop the leak. My question is should the head be resurfaced or am I safe to just throw a new gasket in and properly torque it?

For what it’s worth, the car is stock turbo on 25psi and I have plans to tear down the engine for a 2.2 build next winter.

 

The head will need to be resurfaced.

 

^Yep. Plenty of good reading out there on MLS head gaskets and surface finish requirement for proper seal.

Honestly if you aren't seeing a degradation in performance and the leak isn't presenting a safety hazard, i'd just keep it rolling and focus on that 2.2 build. If you want to keep an eye on the internal integrity of the HG, oil analysis is cheap enough in the interim, and I guess keep testing the coolant for combustion byproduct.

 

Yup. Even just torquing an aluminum head down, the head gasket fire rings almost always leave indentation in the head surface. At 100k miles the head will 100% not be flat once its no longer clamped to the block due to thousands of heat cylces. Used heads with mileage like that usually need anywhere from 3-6 thousandths taken off of them, lower mileage usually 2-3 thou.