i have a 1972 skylark with a 455. i have installed autometer electric guages 5-6 yrs ago. it has a HD 3 core radiator, large oil cooler, large trans cooler, and has had the radiator flushed, has a 160 degree thermostat and good fan shroud and 7 blade fan (with a new thermal clutch fan). the temp guage reads 190-210 degrees. i thought that this was/is off. i found an old record from a repair i had sone several years ago and it said that the actual temp of the car was 25 degrees less than the guage said. i tested this yesterday... the aluminum intake just below the temp guage read 156 deg when the guage read 190. the rad was 143 deg and 140 deg (for water in from the block and water going into the block (i measured the temp on the brass rad. with the paint scraped off). the oil cooler was 138 for oil inlet fitting and the 123 deg for oil back to engine. can the guage be that off? john
John, How are you taking the temperature to compare it to the gauge? Normally, Autometer gauges are very accurate. You might want to get a mechanical gauge, the scale on the mechanicals is much more useable. I like this gauge, it has a line every 5*
i am going to switch to a mechanical temp guage. i checked the engine temp by letting the car come up to operating temp, and stabilize for 20 minutes. then i placed the probe on the aluminum intake manifold just below where the brass fitting for the temp sending unit plugs into the water jacket. i made sure that all measurement for the engine where on the water jacket. also the measurements for the radiator were on the brass side tanks near where the water comes in from the upper radiator hose and from where the lower radiator hose leaves the radiator to go to the engine. i scraped off the paint to get a accurate temp of the metal. for the engine oil i used the brass fitting that join the oil line to the cooler (which is one of those B+M stack type oil coolers-the trans cooler is a BM stack design also. even if there is a difference in the metal temp and the water temp, do you think that it would be 30 degrees? i would only guess that it was 10 percent. also the guage has lines every 20 degrees. that could be some of the problem. or it is just a bum sending unit. if the engine temps were below my thermostat i would be suspision, but the reading on the engine are 160 (from the temp probe on my meter) which is the setting on thermostat. i also calibrated the temp probe, and it is right on (boiling water was 212 deg F and the temp probe was same as my digital room thermostat.). any other sugg would help. john
