Hi guys. I've been having some overheatinf trouble with my 77 electra. Everything seems to be in order except that when i pulled out the thermostat, it was a 195 Degree F one. I've been told that it too high a temp for summer use and to use a colder one maybe 170, 175?? I just wanted a few peoples 2cents on the issue before i buy a colder one.
A 195 degree stat is the factory temp for 99% of all GM vehicles. They do sell 160 and 180 degree stats but your car may run hotter. A thermostat provides a restriction so coolant can stay in the radiator long enough to get cool. If you were to take your thermostat out completely, your car would more than likely overheat because the coolant would be flying thru the rad without getting cool. If this is a stock everyday driver, my best advice is to leave it alone. Buick engineered them to run that hot. If it really bothers you, you can try a 180, but install a water temp guage to monitor the temp. Like I said, it may run hotter
Re-reading your post , I missed the part about it overheating. Sorry, Im a little tired! How do you know its overheating? Did the light come on? Boil over?
Hi temp Hi Guy, The no 1 cause of over heating is poor circulation of the coolant. Either the rad is plugged up or the thermostat is stuck partly open or stuck completely shut, ect, Next up would be failure to hold pressure in the system. [ hole in the system somewhere.] bad freeze plug, heater core,heater or rad hose,bad radiator cap,hole in the rad. ect. Third down the list is the water pump, [leaking, or broken shaft] next will be the fan clutch not operating properly. last and the biggest hassel to fix is combustion gas in the system.[blown head gasket, cracked head or block] WArm the car up and pressure test the rad system and the rad cap. look for leaks, keeping in mind the milage of the veh and the kind of maintainence that it has had. get a rad shop to ck flow down rates. grab the fan blade and give it a good shake to see if it has a broken shaft. and ck the fan clutch to see if it is locked up or has become loose. get arad shop to test for combustion gas in the system especially if the coolant is foamy.
It boiled over completely, while idling. I was installing my stereo at the time and couldnt hear the boil over. Heres the diagnosis. I pulled out the rad, and its shot. All green and flaky, so I'm getting a new one. I swapped out the thermostat with a new 195 stock one. I ordered the "heavy-duty" cooling radiator from Canadian Tire. 177 bucks aint too bad!
The water pump seems fine, same with the fan clutch. Could you describe the "foamy" coolant a little more?? Mine was still clear/green on top but very dark when I pulled off the bottom rad hose. Also how do I pressure check my system??
t-stat... OK, you have overheating issues, BUT a 195 t-stat isnt the problem. First, the 195 is for computer controlled cars (80 ish and up) they used them because the cars can run hotter because the computer controls the electric fan @ a max 240 degrees. A car without a computer uses a 180 t-stat. anything cooler doesnt make the engine happy, and the choke may stay closed or the heater doesnt blow cold. Anyways, the one thing that most people miss in your age bracket of vehicle is the clutch fan. when the car starts up and its cold, the clutch fan will blow super hard until it gets warm, then when it gets hot the clutch fan locks into place and has rapid air through the radiator. Otherwise it "clutches" and sends no air in the radiator, therefore if it doesnt work, then it will overheat. the easiest way to check is two ways... first grab the fan and spin it when cold... does it spin easily?? if so its shot. the other is a timing light. make a mark on the clutch fan blade. start car and let get hot until clutch fan starts to force air in radiator... now air timing light on the fan blade, find the mark, if it isnt staying in the same place, the clutch fan is slipping. So, first thing, replace radiator, FLUSH system. (I usually take off heater line going to from heater core) put hose in new radiator until old coolant is gone, stop putting water in car,,, keep running until all water comes out of heater core lines... usually about 1 minute or less. Now, shut off car. Put hose back onto heater core, fill radiator full of antifreeze. This will usually be about 1-1 1/2 gallons. run at idle DO NOT RACE MOTOR or boilover WILL occur... wait for air bubbles to come out.. this will take about 10 minutes. (so t-stat will open) when radiator is full, shut off car...wait 5 mihutes for antifreeze to settle. install rad. cap, and you should have no problems. good luck!! steve
Sorry, but am I missing something here? TMO, the thermostat ensure that the engine reach normal operating temp. as fast as possible, (by closing of the flow of water through the radiator). Installing a fast/early 160 degree opening thermostat will keep the engine operating cooler than a slow/late 190 degree therm. Running the engine without a thermostat will cause wear of cylinder bore, rings, etc, as it will never reach the temperature the engine was designed for. You can use a 190 in the winter to ensure proper heater function, and a 160 in the summer to prevent overheating of the engine. "Computer" monitored injected engines should use original thermostats , as the temperature of the engine effect the fuel system/MPG. Agree? Per. :beer
Thermostat sets minimum running temp. Good radiator and fan set maximum running temp. Run any stat you want. It doesn't matter. As long as the radiator and fan are efficient enough, the temps will stay down. You seem to have a clutch fan failure. That one strikes at extended idle. You don't need a radiator. That failure would happen on the road at speed over distance. A thermostat stuck shut would overheat to boilover within 15 minutes from stone cold startup. Also, not your problem. Get a nice four seasons clutch fan from your local parts house.
If you fan and water pump are OK, It seems that your overheating problem was radiator related nothing else. Before emmission requirements (pre 70) a 160/170 thermostat was the norm for maximum economy and minimum wear. the 180 plus were required for emission control only which also required a corressponding increase in radiator pressure to prevent premature boiling.
Thanks for the help guys, but my rad was shot anyway so i got a new one. I'll definately buy a new fan clutch too, although my temps seem to be down now. I was idleing for an hour or so, my temp never passed 90 deg celcius. Is this good?
It was fairly warm out at the time, not too hot, a comfy warm, but a bit humid. My new stats the stock 195 deg F one.
thermostat problems I just had the same problem with my '72 Electra 225. I had plenty of fluid in the radiator, the water pump works, but my engine started to run a little hot. After I replaced the thermostat, I haven't had the problem. I put in a 180 degree thermostat. I believe the auto store sold them as low as 140 degrees, but I don't think I'd put one of those in an engine as big as the ones the Deuces have.
