A) My understanding is that ATF levels in my '97 DeVille (and every other car with automatic I've ever owned) have to be checked with the engine at normal operating temps and while idling. But I noticed that there was a very prominent "COLD" range on the dipstick between the tip and the normal markings used to check the fluid levels. What is the purpose of this range? Can you indeed reliably check ATF levels with the engine temperatures relatively cool? If so, that would eliminate a lot of the risk for burnt knuckles when pulling the stick from one of these cramped Northstar engine setups. Or is this yet another example of mysterious GM part markings with no real functionality?
B) On a somewhat related topic, I've always wanted to know why you can't check ATF levels on a stone cold engine at a dead stop, even if only for the purpose of seeing whether you have a major problem that deserves a closer look. Assuming that the fluids drip down to the "sump" of a transmission overnight, why can't you check the level in the morning before starting and use some other marking way up the stick to see if there is **approximately** enough fluid in the car? I'm not talking about checking whether it's a half pint too low; I want to see if there is more or less enough fluid to get to work. What makes ATF fluid levels so much different than oil levels and the like?
Thanks!
Nick
nickpace@rand.org
