strange temp gauge activity

[D_Train]

Originally Posted by mrnickleye

OK...I'll spill the beans. Mine did the same EXACT thing.
Block test showed no problems.

Finally (a month later) put the smog machine tailpipe tester probe at the open radiator cap while engine was idling.
BINGO.......a few hundred HCs. = BHG

All better now, 2.3 years.

PS: coolant goes into overflow bottle from engine, which leaves air is in the passages.

Over night the coolant should get sucked back into engine as it cools down.

Thats what it does. I'd just hate to pay a shop all the fucking money and then have it not be it. i'm gonna try the thermostat first.