turbosix

its been on and off near freezing for the past few weeks.. like 80* then 38*... wtf?

changes constantly

ctscna1

you can try to test your gauge to see if it works. Just find a 1 wire connect near the theromstat housing(black connector) and ground the connector. The temp. gauge should topped out.

91LS400LEX

On both of my LS400s, they would stop at that third line up (near the 1 on the tach), just less than 1/2 way up and stop. I was told that point was normal.

PK_Celsior

iTrader: (18)

yea i think thats normal because thats how mine is third line 1/2 way up and stop. i changed out my water pump thermo and what not. i did all my service for 200k and a lil extra

turbosix

just picked up a new stat from park place lexus of plano for $14.98

will report back and let you guys know if my temp gauge goes any higher than the OP's guage and if my heater starts workin again

turbosix

temp gauge is about where everyone else's is... the old stat wasnt closing fully and the rubber seal had been eaten away and warped allowing even more coolant to bypass keeping my temps low.

cool deal, cleaning the gasket surfaces and draining the coolant took longer than putting the stat in.

note to anyone, if you are gentle pulling out the old stat you can re-use the rubber gasket without issue.

and fwiw, factory stat is 82dC which is 180dF (well 179.x but whatever :P )

CptnTonus

I vote bad thermostat. I had the same problem on my LS, changed the thermostat, and it was much better. Normally my gauge is just slightly above the 3rd line when the car is at full operating temp. When the coolant temps are lower like that, the car will run richer and your gas mileage will suffer.