Engine Temperature Gauge, where does yours average

[Chief Brody]

When I drove today after changing distributor, plugs and wires and setting timing to 12* my gauge was consistent at the 75% or 3rd mark of the idiot gauge. It used to run just right of straight up center.
I wonder if 12* is not where it needs to be and I need to change the timing or is the 3/4 mark normal?

This is the gauge style:

 

[ktmoutfront]

Mine ru s just below 1/2. But these gauges vary so much that I carry a remote thermal temp sensor to check the sending unit to the gauge.

 

[Wes Harden]

Yes your timing can effect temp

 

[diesel4me]

Factory gauges aren't that accurate in my experience--I have added aftermarket gauges to a few trucks I've owned and I prefer mechanical gauges vs electrical ones,nearly every truck that had an aftermarket mechanical temperature gauge installed read lower than the factory electrical one,which relieved my fears the engine had a overheating issue..

As long as no coolant peukes out of the overflow into the tank after you shut it down,I'd say its most likely not running too hot..

Having the timing retarded will make it run hotter--many engines after 1970 or so had a ported vacuum switch to give the vacuum advance full vacuum at idle after reaching operating temperature to help them run cooler,it also kicks up the idle speed a bit..

 

[dyeager535]

Mine also runs just under the center mark in normal conditions. According to the CTS, that's right around 195*.

I don't use the gauge as anything but relative. Even if they are inaccurate (IME they are accurate) their purpose is best used for a relative measurement. If it's always run at the same position, but is now higher or lower, you have an issue. Assuming the gauge was working properly from the get go.

 

[Chief Brody]

I will fine tune the timing using the intake vacuum gauge and see where the sweet spot is.

 

[fordsucks!]

Mine runs 60-75% up the gauge. Gauge looks like overheat, but motor runs cool. 195 at thermostat neck. I have replaced the sender, the gauge, thermostat, radiator, and the gauge still reads High. A few people here suggested the green printed cables behind the gauge cluster should be replaced, I have not done that yet.

 

[Chief Brody]

Mine runs 60-75% up the gauge. Gauge looks like overheat, but motor runs cool. 195 at thermostat neck. I have replaced the sender, the gauge, thermostat, radiator, and the gauge still reads High. A few people here suggested the green printed cables behind the gauge cluster should be replaced, I have not done that yet.

My gauge always ran just a tick right of center. I've replaced the printed circuit in mine twice. I am going to give the timing adjustment a try. It doesn't help that it has been 96 degrees here...but it's running a tad hot and I don't like it.

 

[fordsucks!]

My gauge always ran just a tick right of center. I've replaced the printed circuit in mine twice. I am going to give the timing adjustment a try. It doesn't help that it has been 96 degrees here...but it's running a tad hot and I don't like it.

Let me know if the Timing works for you. I've given up on mine, the gauge looks like this whether it's 60* or 115* outside...

 

[diesel4me]

One episode of "Car Talk" with Click & Clack the Tappet brothers,told how one of them owned an old flat nosed Dodge van,that always had the temperature gauge reading in the "hot" zone,yet it never seemed to overheat or peuke coolant out of the overflow or radiator cap..

He tried replacing the temperature sending unit,thermostat,flushed the radiator,fiddled with the timing,nothing seemed to make any difference..then he replaced the gauge itself,and it still read "hot"..
Now he was getting angry!..

Finally after his brother convinced him it was not overheating,just the gauge was not reading accurately ,he decided to hook up a mechanical gauge,in addition to the factory temp gauge..it read "normal",about 180 degrees...he said he got so aggravated he smashed the glass over the factory temp gauge,BENT the needle till it read 180 degrees,and said he drove it over 100,000 miles without it ever boiling over....

 

[dyeager535]

I've not done it, but I'm assuming that the gauge reading is "adjustable" via the resistor on the back.

I *have* heard of that going bad.

Really they are pretty simple circuits. 12v, ground, and the sending unit wire from the temp sender. Easy enough to test by temporarily hardwiring as above, which eliminates all the connections as a potential failure point. You can also test a bit more roughly by disconnecting the sender wire with the key in run, checking gauge reading, then grounding that wire (to a good ground) and checking again. It seems the gauges will "peg out" at roughly 9 and 3 o'clock. All the connections between the sender and gauge are likely culprits. If the gauge reflects the temperature climbing as the engine warms up, you know it's not a complete failure.

If nothing else changed, I'd inspect the under hood wiring closely. If you were working under there then noticed an issue, would be pretty coincidental that something in the cab just happened to randomly fail.

 

[blazer74]

Just above the first mark forever.
Goes to straight up until the thermostat opens. My sender is in the intake due to a vortec head and intake conversion causing the initial reading. Didn’t do that before the vortex’s.
I think one time it actually went to the 2:00 position on the hwy and was a little hot years ago.

 

[Chief Brody]

I got one of those infrared thermometer things to help with my timing fine tuning / running hot adventure

 

[Chief Brody]

I also need to troubleshoot my fuel gauge...it driving me crazy.

 

[fordsucks!]

I've not done it, but I'm assuming that the gauge reading is "adjustable" via the resistor on the back.

I *have* heard of that going bad.

Really they are pretty simple circuits. 12v, ground, and the sending unit wire from the temp sender. Easy enough to test by temporarily hardwiring as above, which eliminates all the connections as a potential failure point. You can also test a bit more roughly by disconnecting the sender wire with the key in run, checking gauge reading, then grounding that wire (to a good ground) and checking again. It seems the gauges will "peg out" at roughly 9 and 3 o'clock. All the connections between the sender and gauge are likely culprits. If the gauge reflects the temperature climbing as the engine warms up, you know it's not a complete failure.

My gauge did not have any resistor or any adjustment points on the back. Just four prongs sticking out and that's it.

I tried your test method, and did not get the gauge going to 9 and 3. Instead, It went from maybe 10 to 3.. the full hot Peg was farther than the full cold Peg. and I tested this on two different gauges with the same results.

Someone here on the forum was nice enough to try the same test for me, and they got the same results. Full hot Peg was farther than full cold Peg on their Truck

 

[dyeager535]

Huh. I just went into the garage and looked at two of the coolant temp gauges I have, both have resistors. I assume they could have used them without if the gauge was accurate as-made.

 

[chulisohombre]

Mine stays around 1/3 to half most of the time. Sender in top of the thermostat housing.

 

[trukman1]

Yes your timing can effect temp

This!

 

[chulisohombre]

Having your timing off can do a huge difference in temps. If the engine is firing at the incorrect time it will build up excessive heat in the cylinder and not be very efficient. If you are far enough off you can see the headers glowing red from overheat. Good way to burn off valves as well.

 

[fordsucks!]

Huh. I just went into the garage and looked at two of the coolant temp gauges I have, both have resistors. I assume they could have used them without if the gauge was accurate as-made.

here's the back of a 1980 K5 coolant temp gauge, let me know if I'm missing something. Is the ceramic piece a resistor?