Date: Wed, 25 Feb 1998
I recently purchased a '72 1800 ES in very good condition. Everything works, new leather, good body, etc. However, the engine temp gauge warms up to almost the start of the "red zone," the outside temperature being about 40. Is this normal?
I once owned a 142E that also seemed to run hot until we took off the "clutch fan" and put on the earlier "non clutch type" . Should I consider doing that or are those Smiths gauges just inaccurate?
thx: Randy
gm@mtnwestprinting.com
Randy - It is not normal for your ES to run hot in cool weather. The troubleshooting steps for this problem are:
1. Check for obstructions to airflow through the radiator. Make sure the fan is turning. Check engine ignition timing and dwell.
2. Check the temperature gauge for accuracy. Remove the coolant temperature sensor from the cylinder head and place it in a pan of boiling water with a kitchen thermometer. If the thermometer reading is much different from the dash temperature gauge reading, the gauge needs adjustment or replacement.
3. If the gauge is o.k., drain some coolant from the radiator and remove the thermostat from its housing under the top radiator hose. Note the temperature rating stamped into the metal of the thermostat. I recommend using a 180-degree-Fahrenheit thermostat (82 degrees Celsius). Check the thermostat by heating a pot of water on a stove. Place the thermostat and the kitchen thermometer in the pot and make sure the thermostat is fully open at the designated temperature. If not, replace the thermostat.
4. If the thermostat is o.k., flush the radiator, block and heater with a 10-minute commercial radiator flushing solution from the local auto supply. Follow the directions on the container and be sure to drain the engine block as well as the radiator before refilling. Always use half-and-half water and anti-freeze in the cooling system.
5. If flushing doesn't fix it, bring the radiator to a radiator shop and ask them to clean out the passages.
6. If you still have overheating, you may need an engine overhaul. If you have recently completed an engine overhaul, wait until you have several thousand miles on the engine. If it still overheats, consider using a thicker head gasket to reduce the compression ratio.
Most of the above procedures are recorded in the Haynes manual for the Volvo 122 and 1800. To answer your question about the fan clutch, it is possible that this unit could malfunction, but not likely. I would put its replacement just before the engine overhaul step. Good luck. -Glenn.
Date: Wed, 25 Feb 1998
From: gm@mtnwestprinting.com
Glenn, thanks for replying so quickly. One of the problems here is that the gauge has no numbers on it, just the three green areas and the red so I really have no idea what temp it is telling me. Is the red zone a given temp that I should know?
thx again; Randy
Randy - I looked in my books, but could not find a temperature chart for the gauge. I don't have an owner's manual, and that would be the most likely place to find this information. It's safe to assume that the red zone is the danger zone. I would check the accuracy of the gauge using the aforementioned pot of hot water and kitchen thermometer. Even if you had the temperature chart, there's no guarantee that your gauge is accurate. -Glenn.
[Most coolant temperature gauges indicate about 1/3 when the temperature is normal.]
Date: Thu, 26 Feb 1998
Glenn, I tried something a little easier on my father's advice. This morning I stuck the wife's meat thermometer in the radiator after it was warmed up and it read about 185. So I assume either the gauge or the sending unit is off and it's not really running hot. The local Volvo shop agrees.
Thanks again, Randy
That gauge looks really nasty to get out, so I'll probably just live with it.
Randy - This is a good plan, but I would caution you to check the thermometer reading against readings from other similar Volvos. The temperature at the radiator opening might be quite different from the temperature at the coolant gauge sensor.
Actually, the best test for overheating is to watch for coolant leaks. If your radiator overflows frequently, it's time to do some work. -Glenn.