304 amc
- Thread starter brewter2
- Start date
Tison78_CJ5
New member
The thermostat in mine is 180 deg. F. So it could be as high as around 210 deg. with a little pressure on the radiator. I couldn't find the normal running temp. but mine gets pretty hot. Probably around 200
69jeepcj
New member
mine ran around 190*-200*, I had a friend that was into hotrods pretty big and he told me 210* was a bit too warm for his comfort. He said the 6cyl run around 210* and that the 304 should run a little cooler. My chevy 327 runs around 180*- 185* Are you having cooling problems?
69jeepcj
New member
do you have a electrical temp sending unit? If so, I would say you need a new one. Sounds like the engine isn't actually getting too hot, but the gauge is reading hot, BAD electical temp sending unit. The cooling system could have a blockage in it too, I would flush your cooling system with a water hose, if the problem still exists I would get the sending unit.
Tison78_CJ5
New member
Several things to check. It is normal that they over shoot, when they first get hot. Mine will about peg for a few minutes. Then it will drop to normal.
If yours is staying high, you have something going on.
One big no no is using regular water in any cooling system. Over time the minerals will clog it up.
Use distilled or RO water.
You can check a thermostat in a pot of water, on the stove. Heat it up, and watch it slowly open up.
Are you sure the gas gauge is right?
The gas gauge regulates the power, for the temp. gauge.
This is pretty close. believe it changes some between different years.
Temp. gauge calibration:
C (cold)........................ 130 degrees--73 ohms
Beginning of band.......... 171 degrees--36 ohms
Top of band.................. 242 degrees--13 ohms
H (hot).......................... 270 degrees---9 ohms
Fuel gauge calibration:
Empty--73 ohms
Half-- 23 ohms
Full--10 ohms
If yours is staying high, you have something going on.
One big no no is using regular water in any cooling system. Over time the minerals will clog it up.
Use distilled or RO water.
You can check a thermostat in a pot of water, on the stove. Heat it up, and watch it slowly open up.
Are you sure the gas gauge is right?
The gas gauge regulates the power, for the temp. gauge.
This is pretty close. believe it changes some between different years.
Temp. gauge calibration:
C (cold)........................ 130 degrees--73 ohms
Beginning of band.......... 171 degrees--36 ohms
Top of band.................. 242 degrees--13 ohms
H (hot).......................... 270 degrees---9 ohms
Fuel gauge calibration:
Empty--73 ohms
Half-- 23 ohms
Full--10 ohms
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carnuck
New member
It could be too much voltage to the gauges. Check the motor with an IR gun. Mine ran 195 all day long (Seattle to Montana and back by way of Vancouver) hauling a 5th wheel behind my J4000 (then I flipped it on my driveway avoiding a horse at night and had to buy a 2wd '82 Chev C20 with 454/TH400 to have enough power to move the trailer)
Turbogus
Active member
Since I first got 'Black Betty' I was chasing an overheat gremlin myself on my 360. Went through and did new Radiator (3 row) refilled with 50/50 premix, turned the electric fan from pusher to puller, new relay controller, new hoses, new coils in both upper and lower Rad hoses, new high flow thermostat, new FlowKooler water pump, new senders and gauges over the span of several months but still was peaking out at 220*
I had done some reading about the Contour fan setup here and elsewhere and was a bit intimidated with forum posts running the gamut between I've burned out the motor to needing to drill holes in the high flow thermostat.
Ulitmately after much more reading and detirmining whom were the reliable forum members and asking several questions I got the fan out of a Merc Mystique (same as Ford Contour fan) and began the process. It turned out to be much easier than I'd imagined despite cleaning up all of the electrics under the hood as part of this project.
Since all of this work I tested it stationary on a hot day, (for Oregon 90* and 80% humidity) using the three way switch I installed as a part of this project I left the fans on using the two senders. The temperature climbed up to 180* an stayed put. SO I then shut the fans off (override) and the temperature climbed to 210 in just a couple of minutes, I then cut in the manual override for high speed and this cooled the motor down to 140* in less than two minutes. After a little fine turning this thing's been running like a top for over a year now.
I had done some reading about the Contour fan setup here and elsewhere and was a bit intimidated with forum posts running the gamut between I've burned out the motor to needing to drill holes in the high flow thermostat.
Ulitmately after much more reading and detirmining whom were the reliable forum members and asking several questions I got the fan out of a Merc Mystique (same as Ford Contour fan) and began the process. It turned out to be much easier than I'd imagined despite cleaning up all of the electrics under the hood as part of this project.
Since all of this work I tested it stationary on a hot day, (for Oregon 90* and 80% humidity) using the three way switch I installed as a part of this project I left the fans on using the two senders. The temperature climbed up to 180* an stayed put. SO I then shut the fans off (override) and the temperature climbed to 210 in just a couple of minutes, I then cut in the manual override for high speed and this cooled the motor down to 140* in less than two minutes. After a little fine turning this thing's been running like a top for over a year now.
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Usually , if the radiator is cool ad the engine is hot, this indicates that the thermostat is stuck in the closed position!
