2001 Temp hot

DKhorse

Founding Member
Sep 5, 2002
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Philadelphia
I live in Florida so that should tell you something. I have a 2001 GT with a fluidyne Radiator and I also have underdive pulleys. I have a 180 degree thermo. I just had the radiator flushed and filled with Amsoil Radiator fluid.

I still have a overheating problem. It reads about a 1/4 past normal. If I have the air on when on the highway or the city it will creep up. But as soon as I turn the air off the reading goes back to normal. The shop recommended that I go back to a factory thermostat. Do you think the thermo is my problem?
 
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Why the switch to the Fluidyne radiator? Were you having the overheating problem before and this was an attempt to fix it? Is the rest of the cooling system stock? Are the underdrive pulleys your only other mods?
 
I probably would start with the thermostat, it is cheap and personally I would go back to the stock heat range. On a stock motor you really aren't going to see much of a benefit going with a 180. People tend to forget that these motors are designed to operate in a very specific heat range. When you change that heat range you change the tolerances of the motor. Going with a colder thermostat and operating the motor at a colder temperature will increase wear. I am sure there are some minimal gains in power to be had but, at what cost? The real benefit of a colder thermostat is on a motor with high compression or a power adder where the colder temps help prevent detonation. In these situations the added wear is not an issue when compared to the possibility of detonation.
 
Is the system completely filled, or do you have a lot of air in it? I'm not sure about this Amsoil Radiator fluid, but with regular 50/50 anit-freeze/water mine sits at about "o" in "normal" on these hot days.

You may want to let the system cool down enough that you can open the radiator cap. With the cap open, start the vehicle, and with a flashlight, carefully look into the radiator and see if the coolant is circulating. It may take a while, and if it starts to boil-out, shut it down and let it cool off.
 
I was hoping that the flush would take out any gunk, and air that might be in the cooling sytem. I went to the dealer yesterday and got a factory thermo and o-ring. If I am lucky that will fix it. From all that I have read your help on this is right on.
 
i replaced the thermo, the old one was in the open position when I took it out. I drove for about 20 mile. It would stay below the center point on the gauage creep up a little past then go back down. when I pulled into my garage it was slightly past the middle point on the guage. The outside temp was 105. all in all better, but not always sitting in the middle of the guage.
 
a 180* t-stat does not increase engine wear. it's 12* cooler than stock. the thermal expansion/contraction over 12* for typical metals is going to amount to a wopping .0001" or so. no carmaker in the world is going to manufacture every rod, crank, block, and piston to within .0001".
 
DBMSTNG said:
a 180* t-stat does not increase engine wear. it's 12* cooler than stock. the thermal expansion/contraction over 12* for typical metals is going to amount to a wopping .0001" or so. no carmaker in the world is going to manufacture every rod, crank, block, and piston to within .0001".

Poor choice of words on my part, there is far more to it than just the tolerances. I stand by what I said though, a 180 degree thermostat will produce more wear than a stock thermostat will. The difference may be marginal but, it is far more drastic if you go colder than 180 like say a 160.

Here are some references that can explain the various issues far better than I can.

http://www.garage-pak.com/pat-goss-washington-post/2002-wp-cold-engine-blues.cfm
http://performanceunlimited.com/cobravalley_drivetrain/thermostat.html
http://ca.autos.yahoo.com/maintain/answer.php?coolant_answer8.html

Here is a quote from Federal Mogul's website which sums it up for me.

http://www.federalmogul.com/cda/content/print/0,2196,2442_7359_7519,00.html

If the thermostat needs to be replaced, install one with the same temperature rating as the original. Most cars and light trucks since 1971 require thermostats with 192 or 195 degree ratings. Using a cooler thermostat (160 or 180 degree) can increase fuel and oil consumption, ring wear and emissions. On newer vehicles with computerized engine controls, the wrong thermostat can cause major performance and emission problems if the engine fails to reach the proper operating temperature. Loss of coolant because of a leak is probably the most common cause of overheating. Possible leak points include hoses, the radiator, heater core, water pump, thermostat housing, head gasket, freeze plugs, automatic transmission oil cooler, cylinder head(s) and block.

The bottom line here is I don't believe anyone has any idea or better yet any data to show if they are achieving any gains with a 180 degree thermostat, it is an old school leftover that just hasn't died yet. :p
 
I'd recommend getting the prestone flush kit, the kits only a few bucks and its really handy. It basically puts a water hose attachment in-line in the small heater core hose. The way it flushes/fills its much less likely to have big air pockets. Plus it makes it super easy to do a backwards flush.


BTW, maybe get a more accurate water temp gauge (autometer) or a a tuner so you know what its *actually* running at since you're modding the cooling system. I wouldnt trust the stock gauges at all.