[Hocrest]

Up till about 2 years ago, HG's on this engine were somewhat rare. It seems that age is showing it's ugly head and HG's have been failing more often lately. I wouldn't classify it as a common problem like the transmission, and if they are done properly. The HG's will most likely last another 20 years.

Hopefully the thermostat fixes your problem.

It used to be that I would warn a new member to start saving for a bad transmission. Now it seems that new owners should be warned to save for a transmission and HG's?

edit; And the only time that my gauge has varied from it's normal spot was when my HG's went. In my case it was an external coolant leak, leaking out the bottom of the head between the oil pan and exhaust manifold. Even while lying on the ground under the car on ramps with the engine running at 4k, I was never able to spot the leak. It was only identified when the heads were pulled.