Looking for possible causes of increasing water temperatures… here’s the story (and I’m sticking to it): The last few weeks I noticed my water temp range (after a good 20 min of driving) is now running between 210F – 230F. About a month ago, this same drive and warm-up (and roughly same outdoor temp) my water temp range was between 190F – 210F. Now, I know I’m still within “safe” limits, but I’m curious as to why the temperature range has shifted up? I checked the coolant level… and it’s exactly where it should be. Car has 23K miles (still w/ original coolant). Does the coolant need replacing already? Is the T-stat sticking? (if so, how can this be checked?). The other thing I noticed is that I’m not hearing the cooling fan kicking on (I think it’s programmed to come on at temps over 200F). What’s the best way to test cooling fan operation? Thanks in advance.
Start the car and monitor the temperature. Low speed fan should kick in about 192* and you should hear the high speed fan engage between 206* & 210*. If you're concerned, you can use your tuner to lower both settings. After installing the supercharger, my temps went up some. I lowered my fan settings to 176* and 186*.
Start the car and monitor the temperature. Low speed fan should kick in about 192* and you should hear the high speed fan engage between 206* & 210*. If you're concerned, you can use your tuner to lower both settings. After installing the supercharger, my temps went up some. I lowered my fan settings to 176* and 186*.
Mark.. thanks for this input. I ran it through 5 cycles while idling... fan is off and does not kick on until water temp reaches 215F (on the nose)... it stays on until "cooling" reaches 202F and fan shuts off completely.. then cycles back up to 215F when it kicks on again. These must be the factory settings as I have not flashed the PCM (no tuner). Are the numbers you referenced the Ford specs for the fan? Also, not sure about the low-speed vs high-speed... I'm only getting one speed (215F on.... 202F off). These seem too high....
Start the car and monitor the temperature. Low speed fan should kick in about 192* and you should hear the high speed fan engage between 206* & 210*. If you're concerned, you can use your tuner to lower both settings. After installing the supercharger, my temps went up some. I lowered my fan settings to 176* and 186*.
yeah.. I thought that was too high as well... thx for checking on the resistor p/n... Once I get that, I'll try that swapping that out first before spending too much coin.. hopefully that will take care of the problem.
Decided to take the pony to the dealership to look at the cooling fan issue. I was surprised (actually mildly shocked) with their synopsis: "Used IDS Ck LSPD and HSPD function of cooling fan assy, found no faults and system functioning properly. Ran TSBS SSMS found none that apply. Found Fan operation within spec and cycling within parameter.. no need to repair". I asked what the specific parameters are for when the cooling fan engages and was told it's not simply based on 1 parameter such as water temp. It's an algorithm based on multiple parameters under various conditions (service advisor mentioned water temp, oil temp, AIT, engine load, etc.. and that the low speed fan will kick in at different water temp readings depending on the combination of these other parameters). So, basically they are saying fan and fan resistor are functioning normally. My concern is.... if this is true, why have I seen such a dramatic shift up in temperature range (i.e., used to be consistently lower). Anyway, publishing dealership findings for others who may be curious/concerned about operating water temps and cooling fan operation.
very interesting... for a wile now i have thought my car was running hotter then normal but now i see that's not the case. i have a interceptor gauge that i have set for water temp, at a normal running temp it will sit at 192, sometimes hitting 196 sitting in traffic.
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2005 Mustang GT Paxton Novie 1200SL Supercharger, C&L 95mm Mass/Air sensor, 39lb injectors, Motoblue ignition coils, Motoblue throttle plate spacer, Borla XR-1 Long Tube Headers and no cat x-pipe, Hooker Aero Chamber muffler, Custom LaMotta Performance tune, G-force tires, B&M shifter, Kennybell b-a-p, Steeda streat wing, RKSport California Dream Ram Air Hood, AEM analog A/F gauge, Interceptor scan gauge, McLeod RST clutch
MMR shortblock all broken in!
intercooler/smaller pully to come...
i have a interceptor gauge that i have set for water temp, at a normal running temp it will sit at 192, sometimes hitting 196 sitting in traffic.
Thanks for the input. I have the PLX OLED OBDII gauge for monitoring my PIDs. If your temp only hits 196*, sounds like that's when your fan turns on. I tested mine numerous times, and my fan won't engage until 215*.... but according to Ford, that is within spec... seems like a wide spec range.
Opinions on rising water temp range 
