Engine cooling question

Ok, here is a weird one, not really an issue but I am wondering if anyone has had a similar issue. In the am my temperature is roughly 10-25 degrees warmer than in the evening. In the am my factory needle is just above center (70-75 degree air temp) and in the afternoon my needle is below center (85-92) degree outside temp? Weird? I figure it would be opposite but it is not? Any thoughts? Again, not an issue, just trying to figure out the science! Thanks!
 
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In my experience that is normal, thermostat is opening and closing more in the AM to keep engine at temp. When it's warmer out thermostat stays open more. And always remember gauges are a guide, there not always 100 percent exact. If your worried hook up a temporary manual temp gauge and compare the two.
 
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I would guess your sender is not functioning the greatest. Remember your gauge sender is in the intake manifold, therefore it will read the temperature that is modulated by the thermostat. It should get up to thermostat temp and then basically hold there (unless you are building heat to a temp higher than thermostat).

I would see AM and PM outside temps similar to yours and my gauge is consistent AM or PM. Saying that I also had my sender fail and it didn't work at all then.

When I replaced it, my gauge now reads about 10* higher than it did before (before was almost bang on the right temperature).

Another thing to check would be the connection at the sender. It is only a push on socket. If it is oversized it may not be making a good connection. If it is wobbly, try squeezing it a little with some pliers to get a tighter fit on the sender stud.

Let us know how it goes.
 
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I would not put too much faith in that sending unit and gauge. They have been known to be off quite a bit and vary their reading depending on how cloudy it is.

It's good for a spot check to make sure your car is warming up, or not blazing hot, but I wouldn't focus too much on getting an accurate reading. Add an aftermarket gauge if you want to see true temps.
 
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I would guess your sender is not functioning the greatest. Remember your gauge sender is in the intake manifold, therefore it will read the temperature that is modulated by the thermostat. It should get up to thermostat temp and then basically hold there (unless you are building heat to a temp higher than thermostat).

I would see AM and PM outside temps similar to yours and my gauge is consistent AM or PM. Saying that I also had my sender fail and it didn't work at all then.

When I replaced it, my gauge now reads about 10* higher than it did before (before was almost bang on the right temperature).

Another thing to check would be the connection at the sender. It is only a push on socket. If it is oversized it may not be making a good connection. If it is wobbly, try squeezing it a little with some pliers to get a tighter fit on the sender stud.

Let us know how it goes.
I put a new sender in which remained consistent. I also got a cheap mechanical which also showed the temp diff of 15-20 degrees between am and pm. Regardless, both are within norms, just interesting how this occurs!
 
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