Why won't a 1991 Cadillac De Ville restart for an hour or two after being driven in temperatures over 90 degrees?
I cant give you a definative answer but there are engine protections that shut down the engine to protect it from overheating damage. Are the cooling fans working? Have the codes read. Hope this steers you in the right direction
I have no idea about this specific car, but the alternator in general is an electrical generator which is driven off the engine's crankshaft. It will normally be at one end of the engine and driven by a belt - it is easily identified as it is about the size of a pineapple and is surrounded by coils of wire.
Why does your 1998 Honda Civic LX engine occasionally and especially on hot days quit at startup or when it hasn't been driven far then allow restart after briefly being able to sit or coast?
The first car to use fully interchangeable parts was the Cadillac Model K. On March 5 1908 three Model K's were driven hundreds of miles, disassembled, had all parts jumbled together, were reassembled from parts selected at random, and were driven further hundreds of miles. This feat won the Dewar Trophy for Cadillac. Early Ford Model T cars by contrast still required hand work to fit parts to individual vehicles.
Global warming: A secular increase in average global temperatures, increases driven by man's deforestation and burning of fossil fuels (coal, oil and natural gas). Depletion of the ozone layer: a secular decrease in the "total column ozone" above places on the Earth that are receiving insolation, driven either / both by Nature and Man.
The owners manual has several different weights listed depending on the ambient temperature in which the car is to be driven. 5w30 is recommended up to 100 degrees. over that and it is recommending a 20w50. I would use a good synthetic 5w30 which is good for much higher temperatures and will easily perform well in the +100 degree range as well as the -0 temp range. Mobil 1 or Amsoil fit the bill nicely.
Why won't this 1991 Mercury Sable restart after engine is warm from driving and won't start again until parked one to two hours for cooling?
There might be a problem with the fuel pressure. When the vehicle is shut off after driven for a while, the fuel pressure create a vapor lock in the fuel line. Therefore, insufficient fuel are going into the fuel injectors while you restart. Also, it check for any TSB from ford to see of this a common problem for this vehicle. Good Luck.
How do you know if a reaction is entropy driven enthalpy driven or driven by both enthalpy and energy?
If the ∆H is positive and the ∆S is positive, then the reaction is entropy driven. If the ∆H is negative and the ∆S is negative, then the reaction is enthalpy driven. If ∆H is positive and ∆S is negative, then the reaction is driven by neither of these. If ∆H is negative and ∆S is positive, then the reaction is driven by both of these.