Normal Operating Temperature for Gen 1?

[DeepPower]

I don't trust my dashboard temp gauge, it often shows the car running too cold or a tad hot. From time to time I use a laser IR thermometer and point it as the thermostat to check the temperature.

Last week the temperature was 195F. But today the dash gauge looked a bit high, and when I check the temp at the thermostat it shows 205F. Should I be worried?

 

[DeepPower]

Also, when the engine has been running for only a few minutes the upper-radiator hose is very hard - can't be compressed.

 

[SHOdded]

Where was the temp gauge needle sitting when you checked the hose? If the coolant is warmed up, the hose will be under full pressure, wouldn't expect it to be very pliant (pliant/spongy could mean deteriorated hose). Is the coolant clean? May be time to check the pressure rating on the radiator cap and replace it if necessary.

 

[DeepPower]

Where was the temp gauge needle sitting when you checked the hose? If the coolant is warmed up, the hose will be under full pressure, wouldn't expect it to be very pliant (pliant/spongy could mean deteriorated hose). Is the coolant clean? May be time to check the pressure rating on the radiator cap and replace it if necessary.

When I checked the hose, the temp gauge was above the blue, below the L in NORMAL.

Thanks, per your post I'll replace the radiator cap. Do I get a 13psi or 16psi cap?

 

[sperold]

I would order a new thermostat, and o-ring, and put it in as soon as you get a chance.
When they go, they hunt around for a stable temperature for a period of time. Eventually they fail.
I always boil some water on the stove to make sure it opens, before I install them.
I am always nervous about overheating (even here) so I opt for the 180 over the 195, but that is just me.

 

[DeepPower]

Anyone know the part number for the Motorcraft 180F thermostat? I know the RT-1112 is 190F.

 

[SHOdded]

The radiator cap part number is Motorcraft RS90, 16 psi. Got it off EBay, IIRC, a while back.

 

[DeepPower]

Thanks. I got a Duralast radiator cap with a relief valve. I haven't checked the radiator hose when cold, but I also added about 1 quart if antifreeze.