Has anyone seen leaking head gaskets or replaced head gaskets on a 2007 Infiniti g35 with the hr motor? While I was replacing the VTC cam sprockets I noticed in the valley under the intake manifold that both head gaskets look like they are starting to seep coolant in a few areas between the cylinder head and the engine block.

 

From what I've observed here, there have been a few reports of it happening, but just that.

Certainly it shouldn't be showing evidence of coolant leakage, but do take into consideration that the OEM coolant used has almost a dye quality to it. What I mean is that even the smallest amount of seepage can leave a very damning residue long after any seepage has stopped.

I noticed this around the ends of my radiator hoses when the car was brand new; although they have never progressed further nor has it shown any loss in coolant level over the last 7 years of ownership. Any time a dealership has seen it, they always want to sell me on replacing the "leaking" hoses. When I tell them they've looked the exact same way since new and have never shown any signs of further leakage, they usually back off and quit the hard sell.

Basically, it could be that it has had a slight seepage at some point, but it may not be active now. If you really want to verify it, you'll need look into doing a cooling system pressure test, a cooing system hydrocarbon test, and a cylinder leak-down test.

.02