QuestionQUESTION: 1999 Dodge Grand Caravan 3.3L 144K
Recently the radiator fan failed on this one along with the relay. I changed both! Now I feel that the after market fan module that I put in is not as efficient as the original fan module. The reason being that the engine temperature needle used to stay between quarter and half mark and now it stays just below without AC and just above the half mark with AC on. I can definitely see that the engine is running hotter than before. Now my question is that what is the normal operating temperature for this car and enigne (In other words if temperature needle on half mark is OK?). Should I keep the same fan module or replace with a better one? I am worried about ill-effects of long term use at hotter engine temperatures. Please keep in mind that I live in an area where ambient temperature reach 110 normally during day and often it tops 120!
I will also need your advice on recommended coolant changing interval.
ANSWER: Hi Shafique,
The 'normal' range of the needle is 1/4 to 3/4 of full scale so 1/2 scale on the average is just fine. I would be at ease with the present fan module. On very hot days you might even see the needle rise to 7/8 scale (below the H, at the end of the white line) before dropping back to 3/4 scale and that is not concerning. When it rises beyond that point is a good time to let it cool down. The engine operates more efficiently when it is at half-scale or more so that is not a disadvantage. So long as you don't have coolant loss or the needle goes the H there is very low risk of harm to the engine.
The coolant change interval depends upon whether you use the green or the orange coolant. Green might be changed every 3 years, orange every 5 years, assuming a tight system. Anything more frequent is probably not necessary or economical.
Roland
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QUESTION: Thanks for the very quick response!!!
Just for the peace of my mind, when you say very low risk of harm to the engine, does it also include no harm to the transmission?
Normally I try to avoid city traffic on hot/humid days.
I will definitely rate you as the best. I always get the perfect answers to my problems from you. Thanks!!!
AnswerHi Shafique,
The transmission is cooled via a separate core that carries the transmission fluid, next to the engine coolant core. There is a temperature sensor in the transmission which will modify the function of the transmission when it senses a high operating temperature than 240F so as to protect it against damage. If you suspect an issue with transimission overheating you can do a fualt code check using the igntion key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see the mileage reading change to show 4-digit numbers preceded by a P. The overheating code is 1750 if you want to watch for it. But I doubt it will be an issue.
Thanks for the kind remarks and evalutions.
Roland
