It takes me back.......I needed to change the hydraulic lifters on my engine. It was over 90k miles, and ran pretty well, as I thought. When I lifted the valley gasket, I faced the usual black tar. It was as if someone had poured a few litres of quick setting tar over everything. I did change the lifters, but was never happy that it was impossible to clean that tar off. I also found that some of the cam lobes were almost gone, especially the rear one, which effectively had no cam remaining.
A year later that engine came out and was replaced. The tar, even inside the front cover, came off in chunks like toffee.
