Twice while my family and I were traveling in the high country (Yosemite) and after a few hours of driving sometimes at around 65mph or more, we begin to descend from the peak. Suddenly and without warning, the car feels heavy and pressing the acceleration peddle does nothing. A few seconds later the ignition and other indicators light up on the dash board. The car has stalled. No brakes, no steering and in most cases, no place to park. Once we finally parked the car in a safe place, we begin inspecting the vehicle. Coolant looks fine, oil is good, electrical looks fine, etc. I remove the air filter to inspect, it looks fine. After a few minutes of allowing the car to cool, I start it back up, and the problem appears to disappear for a few years! Yes years.
Does anyone know if these cars have problems with the combination of altitude & heat? As this may not seem like that severe of a problem, it puts us in extremely dangerous conditions. Usually when the car is brought in, the techs end up not finding the problem and charging me for other stuff unrelated.
I've done a lot of driving at altitudes between 7 and 11,000 feet and I can think offhand of only two things that are in my experience unique to high altitudes that might cause that type of problem.
The first was very common in the 50s and 60s and was vapor lock caused by fuel in the lines to the carbuertor and in the fuel filter bowl vaporizing due to extreme heat. I don't think that would be a problem with the Quest since it's not carbureted but I wonder if something in the fuel delivery system is getting very hot after the pull up and for some reason causing a problem on the down grade. The few hours of driving you mention would indicate that it's gotten pretty hot. I suppose if there's a line from the gas tank and fuel pump that passes very close to something hot the fuel in the line could vaporize and that would happen more commonly at high altitudes where gasoline vaporizes more rapidly.
The other might be related to altitude and pressure in the gas tank. It'd be interesting what you'd hear if you removed the gas cap and listened... But then why would it only happen going downhill? Was there plenty of gas in the tank? Or were you, as I am prone to do, counting on the very high mpg that you get as you go downhill through Yosemite?
Since it's on the downhill, I'd assume you're NOT accelerating so if you're a typical city driver in the mountains you are probably still in Drive and have your foot off the gas and the car is probably in overdrive. The engine would then be more nearly idling. I wonder if there's a sensor of some sort that's acting up or the idle suddenly drops so low that the engine dies? I'd suspect this would be the most likely situation.
Me, I would always downshift and let the engine provide some braking on the downhill and it would be less likely that the engine would die with too low an idle speed. I'd rather have brake linings cool when I need to stop rather than ride the brake like so many of those flatlanders whom I've followed down both sides of Tioga Pass.
Does it start right back up after you find a place to stop or is there a problem until it cools?
Come to th> Twice while my family and I were traveling in the high country (Yosemite)
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