temp. gauge spike

[Anonymous-0]

Hello to all. I have a 1955 ford 860 with a 172ci gas engine that I partially rebuilt last year with new valves, head, radiator, gages, carb, thermostat and just about every thing else. The problem I have is when the tractor is first started the temp. gage rises, after a few minutes, right to the red zone on the gage. The temp.will go to the middle of the green zone after a few minutes. This has me a little concerned. This happened even with the old parts. Other then this, she runs great. Hope I described this OK. Any help would appreciated. Thank you very much Jeff

 

[Gleanerguy]

The gauge itself might be bad and nothing else wrong. Get hold of a thermometer that will fit in your radiator and read high enough. Then start your tractor up and read the thermometer at the time when the gauge spikes to the red. You will quickly know if you actually have a problem or just a bad gauge.

 

[Gleanerguy]

Another thought for you. If the gauge test shows that your gauge is accurate, then the most common problem that would cause an erratic spike like you mentioned would be a sticky thermostat.

 

[Old Ford Mechanic]

Jeff,what degree thermostat are you running in that engine? It sounds as though the engine is getting too warm before the thermostat opens.I think a 160 degree is what should be in there.It may have a 195 degree in it that is not working properly.Regardless of whats in it i would replace it with a new one.

 

[Greg_Ky]

It sounds like the thermostat may be in backwards.
If the gauge is ok check the thermostat - pointy end towards the radiator, flat end towards the engine.

 

[dan hill]

The thermostat and the engine heat sensor are far apart in the cyl. head.Thrmostats open gradually, not all at once.A meat thermometer can tell you at what temp the thermostat opens.Read the radiator top tank from a cold start.The temp will increase in the tank when the thermostat starts to open.Have some one watch the temp gauge while the engine is warming up.Remember that no water is moving until the thermostat starts to open.My truck gauge shows the same action and you can see the thermo open and close in cold weather.Test the thermostat in a tuna can on the stove.Watch the temp rise and note when the thermostat starts to open.I saw meat thermometers for sale for 1.75. when I was buying light bulbs.The first thing I do on overheat complaints , check the top tank temperature.Themostats seem to stick open or shut,you wont find many far off their marked temp.It was common to use higher temp thermostats in winter when I worked in service shops.The thermostats were tested when they were changed.

 

[sotxbill]

there are two type of thermostats.. the older ones tend to open fast and quick cool off then close again, so they will ping pong a bit.. the more expensivine ones will vary and keep the temp very precise.(emission types)


as to the going red then green... themostat could be backwards, or more commonly is that some engines can trap cold water at the front of the engine due to water pump pressure against the thermostat.. meaning that they will do exactly what you describe. the fix is to drill a small hole, the size off a match stick, in the flange, so that the water will move ever so slowly through the engine..this means as it warms up there will be a small flow that stops hot spots, and more importantly it move the warm water correctly to the back side of the thermostat. this will make it open with out the jump. some of these themostats with small holes in the edge or flange even have a small one-way valve in them so that water flow forwards but not backwards..

The 3 cyl gas engines were very bad at the jump problem as the thermostat was located out on the end of the intake manifold. I have had to drill a small compensation hole in many of them if a diesel thermostat was used instead of the gas thermostat. hth.. bill