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Old 01-17-2012, 11:28 PM   #1
Tankzor
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Bad thermostat ?

So on a way home from vegas I let my friend drive home because I was really tired and forgot my glasses ( difficult to see at night). Anywho we were about 20 miles from home and my friend says the car feels like he has no power steering. I look at the temp gauge and sure enough the car is overheating. We pull off the freeway and the car completely dies.
We tow it home and the next morning I go to inspect and notice that the serpentine belt was completely demolished.

I replaced the belt and the car runs good while it warms up. It even manages to remain at dead center for a few minutes. However the temp gauge will begin to rise fairly quickly .

The engine runs good to me. Still strong, no unusual noises or smoking. It just overheats after a few miles of driving.

Do you think the thermostat gave out during the initial overheat?

I would appreciate any suggestions or help you guys can offer.
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Old 01-18-2012, 12:13 AM   #2
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Could be your water pump failed. My thermostat valve is stuck open I believe too and it takes my car almost 30 min to be at normal operating temperature because extra coolant i think is being used through the radiator when its not needed and I've been driving around with it for a week now and no SES light but I heard if you keep driving with the car overheating you could potentially blow the head gasket and potentially ruin your engine big time. I would check all cooling components if you haven't (water pump, tstat, radiator hoses, expansion tank).
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Old 01-18-2012, 12:44 AM   #3
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Did you check the water level?
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Old 01-18-2012, 02:26 AM   #4
Tankzor
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fluid levels are good, I am afraid perhaps my thermostat is stuck close. car warms up fairly normal. If I were to take the thermostat and water pump out, what exactly will I be looking for to know if its a bad thermostat or water pump?
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Old 01-18-2012, 04:35 AM   #5
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Have you read the codes?
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Old 01-18-2012, 04:52 AM   #6
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i think our t-stats have a fail safe that they get suck open.
i agree with the water pump suggestions. Youre overlooking a critical bit, WHAT made the serpentine belt break? This is usually a broken water pump.
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Old 01-18-2012, 06:03 AM   #7
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Check the pulleys of the tensioners as well. The WP could be fine but a pulley might have slipped. Have you heard any high pitched screeching noises?
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Old 01-18-2012, 07:22 AM   #8
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What about the fan? The t-stat should fail open, and the waterpump usually will self destruct if it fails. If it takes so long to overheat it sounds more like the fan.
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Old 01-18-2012, 10:48 AM   #9
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Please stop spreading this BS that the thermostat fails open. Totally untrue!
Bleed the system and if the over heating continues, change the thermostat and check the pump for leaks, bad bearing and possible impeller failure. Depending on your miles, you may want to just go ahead and put a new pump in. My original pump was changed at 114K. The bearings were loose and it was weeping coolant. But, Ive heard of failures a lot sooner than this. Rollers/tensioners could also be bad causing the belt to go.
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Old 01-18-2012, 11:01 AM   #10
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Please stop spreading this BS that the thermostat fails open. Totally untrue!
+1

I am thinking you pushed the head gasket, or maybe you have an issue with your fan. Is the car auto or manual?
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Old 01-18-2012, 01:07 PM   #11
Tankzor
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The idle pulley completely broke off which I believe led to the destruction of the belt. I replaced the idle pulley and installed new belts. I will try to bleed the cooling system tonight and see if that helps any.

All I have to do is let the car warm up and loosen the bleed screw correct?
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Old 01-18-2012, 01:18 PM   #12
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Make sure heat is on max with the fans running. Center vent thingie set to red, as well. Crack it and wait for the bubbles to stop. If it's really bad, you'll just get air hissing out...make sure it's coolant coming out as soon as you open the screw. Might have to repeat this process a few times, but I doubt you've lost much. Missing pulley = not enough belt tension = slipping water pump. Definitely what the problem was.
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Old 01-19-2012, 11:36 AM   #13
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Ignition on and high heat selected to open the heater valve.
Engine off and perferrably cold, car on level ground.
Remove the bleed screw and pour coolant into the tank until the level comes to the top of the screw opening.
Stop, look and wait to see if the level falls.
If it does, this is the air coming out.
Add coolant until the level at the screw opening stops dropping.
Voila!
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