Anybody out there running a 190 degree thermostat? And if so, where does the needle sit (on a stock '72) gauge?

I noticed a while back that I had no thermostat in the system, so when I changed my water pump I also put in a new thermostat. I let it run after installation for a good twenty minutes and no over heat and good heat out of the defrost.

Ran down to get a bushel of blonde lager and the damn thing overheated, not quite in the red, but definitly hot. When I finally did get the cap off, the coolant level was right where it should be.

??????????

Also, now that I have made these changes, upon a fairly modreate rpm, I hear a new noise in the heater core / valve that sounds like the "woosh" of water that was never there before this surgery....

Any advice on the two questions?

Thanks all...

Brian

Well with a 180 degree thermostat it should read just past halfway on the gauge.

The noise you heard in the heater core might have been trapped air. You can try to run the car at idle after it has gotten up to operating temperature with the cap off and turn on the heater to let the coolant circulate through the whole system. With the cap off you will allow any trapped air to escape. Then re-check your coolant level to see if it has dropped any. If not, the air is gone.

I'd be tempted not to run a 190 degree thermostat for the simple reason that the temp gauges aren't all that accurate and it leaves little room for error. If you overheat the engine it could warp the head. I'd go for a 180 or possibly a 160 degree thermostat, but that is my personal preference.....

I used to run 160 in summer 180 in winter.I then found out my car loves the 180 all the time.2mz's is correct you could have air in the system.Also I have had bad new thermo's.Changing the pump will drain the block.When the thermo opens you must add more coolant because the block refills .If you didn't have to add something is wrong.I assume you did use new coolant 50/50 mix.Oh yeah,My needle is normal on the right down leg of the "M"in TEMP on the gauge face.A "Z" trick.When you replaced the rad. hoses with your pump, put the old hoses under your spare tire.That way you'll NEVER need them!!

One thing to not overlook, is the valve next to the heater core. Make sure it doesn't leak either (check the carpet for a wet spot). If it does leak it may draw in air as the coolant cools down, making it appear the coolant level at the radiator is still normal. The air will have a tendancy to block the water flow also. Do use the 160 thermostat if you are in NC. Hope this info is useful.

Upon further inspection, the auto parts guy sold me a 195 degree thermostat. WAAAAAAAAYYY too hot, now there is a 180 degree in there and things are much better in Zville. The noise ended up being the control valve closed just a bit, way it did not make noise before is beyond me...

Thanks for the info!

I agree that the 180 degree is the best thermostat for almost any car.... I think my Z actually likes being a little hot (acording to the gauge) ... It seems that any Z I have had ran just a little past half way all of the time... I wouldn't worry unless it gets past 3/4 of the way up... Then it is no doubt getting warm... But then I usually just pop the hood and I loose about 20 degrees in a couple of minutes....