93 Sable 3.8 running hot

rclatter · #1 08-12-2005, 12:39 PM

OK, Let me run this up the flag pole one more time and see if anyone can help.
I blew the head on my sable and pulled, planed and reinstalled both heads. Car running pretty well with one exception. The car runs hot randomly. Typically I'll be riding along with temp in low normal, if I turn the airconditioning on the temp will quickly (2-3 seconds) rise to high normal. Turn the AC off and the needle drops sometimes slowly sometimes just as rapidly. I noticed the other day I heard the fan kick into high and noticed the temp again shot up from about mid normal to high normal. Why would the temp go up when the fan is kicks into high gear? By the way does the fan blow on the radiator or draw away from it? I Had never noticed the fan pushes a lot of air back towards the engine. Sometimes it was happening without the AC being turned on and am now thinking it was the fan causing it (or maybe a combination of the two). A/c and heat work 4.0, no white smoke, not losing coolant, engine runs pretty well although it doesn't have the power that it did 10 years ago, but then again neither do I.
Any Ideas? I figured I would replace the temp sending unit. Maybe I broke a wire somewhere during the Head work - there was a lot of wires that had to be worked around and after 13+/- years they're kind of brittle. Sounds like some kind of shielding issue with the temp input to the gauge.

KimMG · #2 08-12-2005, 05:16 PM

Check fluid level. What is the ratio of coolant to water?
Make sure the radiator is externally free of obstructions (bugs, leaves) between the radiator fins. Some people have used a high pressure water hose to clean out the radiator spraying from the engine side to the outside.
Check the radiator for cold spots indicating an internal clog or blockage.
The fan should pull/push air into the engine compartment. Check the fan to make sure it is working properly. Check the fan motor bearings.
Make sure the radiator hoses aren't collapsing restricting coolant flow.

rclatter · #3 08-13-2005, 09:03 PM

Yeah I don't think it's any of those but I'll check the hoses, most have been replaced once or twice over the years. Thanks for the feedback.

rum runner · #4 08-14-2005, 06:02 AM

Quote:

Originally Posted by rclatter

Yeah I don't think it's any of those but I'll check the hoses, most have been replaced once or twice over the years. Thanks for the feedback.

I don't know if I read you correctly, its kinda early for me

You didn't mention thermostat. Not having one will cause water temp to act weird. Sometimes people take them out or punch a hole in them when they stick. If you had engine work, maybe a water port is partially blocked. I would check simple stuff first.

rclatter · #5 08-14-2005, 08:41 AM

Not the thermostat, just replaced it. The key here is what is the connection between the rise in temp and the airconditioning and fan coming on (that's right the temp actually rises when the fan comes on). Note that the temp rises way too quickly for the temp of the water to be actually rising that fast.

rclatter · #6 08-15-2005, 07:25 PM

Check it out. It's not the A/C it's the blower fan. It doesn't matter heat, vent or A/C, the higher the fan speed the higher the temp goes. This has got to be some sort of shielding issue or something. Doesn't it? I changed the temp sending unit and that didn't do it. Anyone got any ideas as to how the heater/a/c blower could be affecting the engine temp?

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