Yes it is.  It's the second 195 I put in it.  But if the engine does not get to 170 will the 195 not open?

1959 Edsel Ranger, 1916 Ford "speedster"
"I may not be a rich man, but I can give you a million dollars' worth of bad publicity."

The thermostat housing should be hotter than the sensor, not cooler.

The thermostat is opening.  The engine simply will not stay cool if it does not.  That's why it must be defective or not 195.


Lawrenceville, GA

So I should get a new OEM 180 or should I get a 195?

Which brand is best?  Stant, Murray, Motorad?


1959 Edsel Ranger, 1916 Ford "speedster"
"I may not be a rich man, but I can give you a million dollars' worth of bad publicity."

Sounds like flow is somehow by-passing the thermostat..  MELs used a couple different dia of thermostat..  Does yours fit snug in the water neck?  Are you getting flow through your heater core?

I’m inclined to agree with Charles and RB. Somehow, water is circulating thru the radiator when it shouldn’t. Most of the temperature post are overheating. Since you’ve got an infrared thermometer, have you tried checking the usual places from cold as the engine warms up? You should see a spike in the temp at the upper radiator hose when the stat opens. At your temperatures, you should be able to do it with your hand. The engine temp, bypass hose temp, water pump temp, should all come up before the upper radiator hose. If it doesn’t, it’s bypassing somehow. When you turn the heater on (water control, not fan) you should see that too.

55 years ago my Dad taught me to never put a thermostat in the car, new or used, without putting it in a pot of water on the stove. Suspended on a wire in the water, not touching the pot. (I got in a lot more trouble than he did for using Mom’s candy thermometer).

You can see the stat open, shut off the heat and watch it close. Pretty good proof.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

I've had this issue of not getting to running temp, especially in colder weather. The first car I sold before ever working out what the issue was. 
My Landcruiser was doing the same thing, running cold in the cold weather. There is a rubber seal on the thermostat that seals it to the housing. With out being obvious the seal had compressed a little and water was getting past before the thermostat was opening. 
If you have tested your thermostat to see that it is opening and closing properly,(I do that even with new ones as I have heard of them being faulty from new) then I would suggest putting some compatible sealer on the outer edge of the thermostat to make sure no water is getting past it. 

This is in the heat of summer.

I know not all thermostats are created alike.    For instance.  My 68 DeVille had many different brands listed, however ONLY the one with a brass foot that reached down into the by-pass was the correct one.  

I will try the hot water test.  However I've had 3 now.  The odds all are bad???


1959 Edsel Ranger, 1916 Ford "speedster"
"I may not be a rich man, but I can give you a million dollars' worth of bad publicity."

All the brands I have tried so far wiggle side to side while sitting in the seat.

1959 Edsel Ranger, 1916 Ford "speedster"
"I may not be a rich man, but I can give you a million dollars' worth of bad publicity."

Your water might have too much lead in it.

"FREE SAMPLE"

It's distilled water

1959 Edsel Ranger, 1916 Ford "speedster"
"I may not be a rich man, but I can give you a million dollars' worth of bad publicity."