The Stovebolt Site Forums The Shop Area General Truck Talk Temperature gauge problem

I have installed a new original type temperature gauge in my 1952 Chevy Pickup with a 1956 235 engine with a 160 thermostat. The gauge works inconsistently. At times after driving for several miles, the gauge goes directly from 100 to 180 at other times it doesn't increase at all until I shut off the engine and then may go up to 180 or all the way to the 220 mark. The engine does not seem to be running hot even on very warm days after many miles of driving. Any thoughts or suggestions.

Do you have the sending unit installed into the head in the original location?

Check all your electrical connections. A bad/loose connection will cause it to read irrataclly.

Since you have an original type unit it is probably in the original location and has no electrical component to the temp reading. It may be functioning correctly. If you run the engine enough to get it to full temp the water within the block and head will continue to get hotter for a short time since it is no longer being circulated. The 160 degree thermostat may be opening and closing resulting in fluctuating temps.

Its a little too late for this advice now but I always compare a new temp gauge's reading by heating water in a pan with a cooking thermometer so I know about what to expect as far as accuracy. There usually are off but as long as it is a consistent error then I at least know where boiling at zero pressure is.

Chuck

yes that is my new rule, always check the temp gage before you install it. They aren't really easy to get to, especially after you just installed it and have to turn right around and take it back out because the brand new out of the box temp gage doesn't move. And you are starting your brand new engine and have no idea how hot it is or isn't. But enough of that, my temp gage bounces around a bit before settling out as well.

yes, don. I installed in the original position but had to use the adapter because the hole in the head on the 235 is larger. Thank you.

Thank you for your reply, johntsmith. Not an electrical gauge.

Makes sense, brokenhead. Thank you for your reply.

Thank you, Hookalatch. Makes sense. I will drive my truck more and for a greater distance and monitor the gauge.

I also have one of the new reproduction heat gauges installed in my jimmy. It works but is kind of erratic and for me functions as more of a guide than a precision instrument. I have a 180 degree thermostat and it more or less reads 180 under conditions I would expect it to. I don't have a fan shroud yet, and in conditions where I would expect the gauge to show more than 180, it does....things like lack of forward motion pushing air through the radiator...low coolant level...bucking a wind or strong side winds.

I think we are used to modern gauges which are much more accurate or at least appear to be to the average person.

Thank you, 50jimmy. That sounds just about like how my gauge acts. I appreciate your reply.
Chuck52

I did forget to mention this is the second one of these reproduction heat gauges I have been through. The first one was very erratic and finally quit working altogether. In general I have a pretty low opinion of most of the reproduction parts I have bought, but they are a necessary evil in my opinion when working with 60 plus year old trucks.

If you want to be certain.....install a second gauge for a while...the kind that hang under the dash. Its like a second opinion at the doctor's office.

I saw an article recently about repairing a non-functional thermal bulb gauge by changing the bulb and tube assembly for one from an inexpensive aftermarket gauge. The procedure looked pretty straightforward, something an average do-it-yourselfer would be able to do. I'm looking for a non-functional original temp gauge somebody would be discarding anyway to experiment on. If it works, it might be worthwhile to write a tech tip about how it's done.
Jerry

Just to round this out a bit, I have an original type gauge on my 51 216 and it is not erratic at all. There is a slight overshoot to 180 during the initial warm up and then it settles down to around 170. I have a 160 thermostat installed. It sounds like the reproduction gauges aren't that great.

Thank you, 50jimmy. Sounds like a good idea.
Chuck52

Thank you for the reply, Hotrod.

Yes, it does sound that way. Thanks for the reply, truckernix.

so through all this does anyone know where to get a decent replacement gage?

1952 Chevrolet truck, 6 cylinder engine, original-style tube?

http://www.chevsofthe40s.com/detail...ERATURE_W_WHITE_NEEDLE_EXC_DD_COE_6.html

http://www.classicparts.com/1949-53-Temp-Gauge-w_-White-Needle-6-cyl/productinfo/24-703C/

http://www.oldchevytrucks.com/cart/product.asp?prodid=REME927&i=10693|||

My picky gene talking ...

When you get your new temp gauge, you may want to reface it and the rest of your gauges and speedo because the "patina" will not match.

I refaced all of the gauges on my '54 including my new temp and gas gauge. Scuffed the gauge faces; painted with flat black (different color for your '52); painted the needles; applied the faces; worked out the air bubbles with a pencil rubber eraser. I also repainted the gauge housings to match the original interior and exterior.

And to complete the look, I bought reproduction chrome plated bezels.

I bought my gauges from the Truck Shop. Bought reface decals from Truck Shop and from Classic Parts. Both decals were the same. I didn't reface the mile numbers in the odometer.

I'm happy with the results.