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Automatic jarring solution: Keep revs high early?

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Old 03-15-2005, 06:05 PM
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Automatic jarring solution: Keep revs high early?

This thread is the continuation of another discussion that stemmed from another thread, but since I didn't want to continue to hijack the original thread, here are the pertinent parts and my follow-up:

Originally Posted by bxb40
Driving when the engine is cold works better if she keeps it in manual mode and does not let the RPMs drop bellow 1500. Car shifts in 4th gear around 25mph (to save gas) and a cold engine does not have enough torque yet and feels confused But should not go beyond 4000RPM either - lubrication might be missing on a cold engine too. In other words, before she hits the highway, better have a warm engine, and higher RPM will do it faster.


Originally Posted by markd
Whoa, interesting! That would likely explain the many threads AT 8 drivers are starting about bad jarring at 35-40mph in 4th gear. Will have to investigate further to see if you are right...



Originally Posted by bxb40
So, did you test this? Basically, drive in second up to 40 mph, then in third all the rest - at least until the engine warms up. Then you switch to auto mode, if you like that one. I usually drive in manual mode - minus on long highway trips.
Gas milage does suffer from overal higher RPM though.


Bxb40: I don't know if you're going to follow this discussion any further, but I tested this theory again today. I warmed it up approximately halfway (needle to 10 o'clock position) and it jarred in 3rd at 27mph, then again multiple times between 39-45mph in 4th, when the temperature gauge indicated that it was already warmed up (though I hadn't been driving it for very long). Not sure if that refutes your thoughts or not...
Old 03-15-2005, 08:44 PM
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Well, my car does not warm-up this fast. Lets say there are 25F outside. I idle in the parking lot 10 seconds, then start driving slow, in second gear, for about 30 seconds. I then stay at the stop light 30 seconds, in neutral. I start and keep it in 2nd for about half mile, then go to 35-40 mph in 3rd for another half mile. After I wait at the second stop light, needle starts moving slowly and 1 mile later is in the middle. I either go manually to 4th or to full auto, as I merge onto the highway. Surely, this is on my way to work each day, so not much variations there. If I leave it in full auto from the start, when I am about to do the 35-40 mph stretch of road, the car is still cold, in 4th gear, and starts jarring several times.
Now, after reading your post, it could be a tranny fluid warm-up issue? It does come from the tranny, it is not the engine sputtering for sure. All I can say, I found something that works on my terrain, so I am using it. What exactly is going on, not sure, I guess an official reply from MNAO would be "Wait at idle for 15 minutes in the parking lot." Like the gas milage is not bad enough to start with and my neighbours enjoy the strong fumes coming out of a cold rotary engine :o)
Old 03-19-2005, 02:38 AM
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I've been following your method over the past couple of days (thus, my temporary disappearance from this thread) and found that a) the manumatic shifting in the morning helps a little bit, though I'm still interested in visiting my dealer to see if they've heard of this issue because I'm not sure if the manual shifting is just avoiding an issue but not solving it, and b) the problem doesn't seem to occur later in the day as often, even when the engine has cooled off for a few hours.

Plus, I'm reluctant to overuse the manual mode b/c my 8 tends to 'learn' my driving patterns rather quickly and it affects the shifting points when it's in full automatic mode. Most of the time, I don't like to rev above 4000 rpm, especially now that I've gotten into this gotta-save-gas-by-driving-conservatively mode. Dammit, you rising gas prices!
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