temp gauge needle position

[bach4660]

curious about needle position on the temp gauge, with the only markings being 100, 160 and 212, is it supposed to be right on 160?

with a 180 thermostat wouldn't it be higher?

 

Currently my needle rides between the 6 and zero of 160. Thinking this is probably around 180.

 

Where does everyone else needle sit?

[Merle Coggins]

Here's mine while out for a drive...

[greg g]

Check the coolant temp with a thermometer.  Why guess?

[JBNeal]

I have had 2 temp gauges repaired, and both times I would take them to the kitchen for testing. I would submerge the bulb in a small pot of water, then get the water boiling, and adjust the needle to 212, then let everything cool off for an hour to calibrate the gauge without overstressing it

[bach4660]

thanks guys. I have driven the truck for 10 years and then on the weekend swapped the rad with a new to me (no known history one). And I thought it smelled hot, then I was watching the temp gauge, but I was thinking it is just because I'm focused on the rad, and never drove watching the temp needle before.

So I bought some prestone rad flush and have been doing the deep clean as per instructions, and tonight (day two) the needle was pretty much straight down, once in a while it would tip to the right above the zero, and then go back down.

 

I realize I should properly check it, but was more curious if this new rad was blocked, and now two drive cycles with the flush thinking it was blocked.  There was something that looked like paper just in the filler neck, wondering if maybe there was a wasp nest inside (or still is), will finish day three, then flush it.

[JBNeal]

That rad flush is designed for modern cooling systems that are designed to heat up fast. The flathead block acts as a massive heat sink, with the tempgauge bulb at almost the warmest point in the cooling system. I have tried rad and engine flushes before, thinking that the entire engine has reached operating temperature, only to check the fluid to find out it is cool to the touch. So I would take the flush instructions under advisement and try a different approach that follows the spirit of the instructions. In the case of rad flush, I would drive around for an hour or so with straight tap water in the system, drain that out, repeat with the tap water and drain, then with the block still hot, add the flush with the tap water and doubled the idle time the flush instructions called for, drain, run with tap water for another hour, then rinse out...got way more crud out of the system that way

[Jeff Balazs]

As a side note it is my feeling that it is best if you have confidence in the numbers your gauges are displaying. A cooking thermometer will tell you a bit.....but an inexpensive Infrared gun is a great tool to have at your disposal. You can actually "see" the thermostat cycling and measure temperatures in a variety of locations with the push of a button.

Taking temperature readings on the intake manifold and carb on one of these engines is a real eye opener.

 

Jeff

[John-T-53]

...and oil pan too. The temp of the oil is really important. If your oil is running on the cool side you will not have proper lubrication.

[Jeff Balazs]

...and oil pan too. The temp of the oil is really important. If your oil is running on the cool side you will not have proper lubrication.

Other than the thermostat......and some sort of a warm up period I don't think there is any provision for regulating this on these engines. It does take a while for these to properly warm up because of the mass of the block. Nothing like a modern vehicle in this regard.

 

Jeff

[55 Fargo]

Here is mine, at 165-170 I think, just hooked this up today, was using a very cheap Eqquis for years...

Is the middle range 160 to 180 ?

 

BTW it's 90 above here today, dry dusty and windy, not our usual combo in these parts..

Edited May 5, 2016 by Fargos-Go-Far

[55 Fargo]

Okay went for a drive, it is 94 f, inside the cab is 100, underhood was 125-130, temp gauge in middle after 10-12 mile drive most of it on the highway.

With my lazer temp gun, temp back of head 180, in front of head 170, at t/stat housing 166, top tank on rad 164.

the real interesting thing is my old mechanical temp gauge sender is still under the hood and was reading the temp too..it is hot

[Probey53]

Can the temp gauge be calibrated mine runs at 212 all the time but don't seem to over heat .

[B1B Keven]

Can the temp gauge be calibrated mine runs at 212 all the time but don't seem to over heat .

 

 

Yes it can. Please PM me.

[NiftyFifty]

You can most likely find a resistor that will bring it down a bit, it would be a bit of trial and error to find the right one to make it the most accurate, but I had to do that with my new gauge set..I was always reading 200 hot, but laser said 170/75..couldn't figure out why my elect fans never seemed to kick in unless it just came off the highway on a hot day...wasn't getting to the 178 the switch needed to turn them on.

[Dave72dt]

You can most likely find a resistor that will bring it down a bit,

 

That works for an electrical gauge.  Like fuel gauges, senders need to be matched to the electrical gauge and sometimes a resistor is needed to get accurate readings.  No place for a resistor on a mechanical gauge.

[NiftyFifty]

Sorry, I missed the original gauge part.....then a pair of pliers and the gauge out of option 1.... Only other way is to replace the spring inside the gauge that is now likely weak and moving more then it should at running temps...or sending it out for a complete rebuild, as I'm not sure the average Joe can get into that gauge and work on it easily...I never bothered with mine...I had a working one from my parts truck, but I never trusted it, so I put a new mechanical one under the dash...now mines electric in the new gauge cluster

[Jerry Roberts]

Can the temp gauge be calibrated mine runs at 212 all the time but don't seem to over heat .

 Yes it can , USUALLY . Each gauge can be a little different . And they can be very sensitive in adjustment , easy to make the situation worst rather than better .  At the top of the gauge you will see a little brass flat bar with a long slot in it . In this slot is an arm from the mostly flat coil of ether , this arm is actually a small wire . If you gently move the wire arm to a higher position in the slot , you will get more movement in the gauge needle , or to a lower position for less movement of the needle .  You might need less movement since your gauge always reads 212 . Or if your needle doesn't return to 100  , you might be able to simply apply pressure to the needle itself to bring it down to the right temperature reading without doing anything else . First you need to find out for sure that your gauge isn't accurate , perhaps using an aftermarket gauge to test . When doing adjustments I usually have a camping stove with a pot of boiling water handy to check adjustments as needed . 

[bach4660]

well turns out I'm thinking I over temped mine and blew the headgasket between 5th/6th cylinder. Just got the head back from the shop today.

Edited June 17, 2016 by bach4660

[NiftyFifty]

Do yourself a favour, spray both sides of your new headgasket with copper high heat gasket sealer...I went through a couple gaskets before I did this, and never any damage to the gasket, but it just wouldn't quite seal dead centre between the cyls and it would start to leak....this time...no issues

[Geekay]

Is it advisable to use a modern manufactured "coolant" in my 1953 Dodge 6 cooling system?

Or, just use 'tap" water or distilled water?

Our town tap water here is highly treated and has fluoride in it..does that matter?

[NiftyFifty]

Distilled water is the best choice if you do want to run straight, or even when mixing with coolant, as the minerals in regular water can build up and form deposits in the system. I'm guessing your not running into any real freezing temps in your location, but modern coolants do have benefits to how they transfer/remove heat, and are a good choice to use in my opinion. Where I live it's not an option, but were more concerned about the anti-freeze side of the coin. You can very likely get away with just a 40 coolant 60 water ratio, maybe even 70/30 and see benefits to runing just water