Transmission rattle anyone?

I'm just wondering if this is something that I need to put on the high priority list or if it's something that can wait until the 10,000 mile oil change. I'm tempted to just let it go for now since the transmission doesn't really have any sort of issues in itself. The car still shifts smoothly, accelerates very well, etc. I am hard on the gas pedal so that's why my econ is so low.

The rattle comes IMMEDIATELY after I let my foot off the gas. Again, it can last from a split second to 1-2 seconds, but never longer. Sometimes it will make the sound, and sometimes it won't. Sometimes it'll never make the sound from the time I turn it on until the time I turn it off. Sometimes it will ALWAYS make the sound. Another weird thing I'm experiencing is with starting the thing up. About 1 out of every 100 cranks, I get a very weird "grinding" sound that lasts almost a full second after the car starts and then goes away and never comes back until another 100 cranks or so.

I had the same problems that ColdFusion had with the mileage (and, still basically have those same kinds of numbers that he has ....even being at 7,500 miles).

Like him, I even took the car into the dealership and they put it on some kind of tester and computed that I was getting 21mpg on "city" driving (which they called a constant travel at 35mph) and 27mpg on the "highway" (which was defined as a constant speed of 60mph). I recently took a trip 300 miles south and back and I was averaging 28.5mpg. They told me that this was normal (of course this was back before I turned 5,500 miles and they used the "give it 10,000 mile" excuse to appease me).

If I don't have better numbers at 10,000, I'm going to be very upset. But, I need to know if anyone might know what this rattle is, because I really don't have too much free time during the day to waste at the stealership.

Thanks guys.

I notice the rattle more so when I really gun it and then let off on the gas. But, I've also found out that if I gradually load the gas with my foot, there's a "sweet spot" where I can get the car to make the rattle INDEFINITELY until I either give it more gas or back off the gas (where it then goes off). See, the thought actually did cross my mind that it might be a motor mount. But, since I'm not driving around with reckless abandon (going fast) and I only drive on two SMOOTH dirt roads semi-frequently (going NOT so fast), I am at a loss of HOW I could have broken one.

Imagine the sound of a mixer beating against a plastic bowl and that's VERY similar to what I am hearing.

I did the following. I found the "sweet spot" (therefore it's constantly making the sound). While I've got the rattle going, I shifted her into neutral AND? No more sound. Take my foot off the gas, shift back into drive on the fly, and put my foot back on the gas finding the "sweet spot" and the rattle comes right back. I also noticed that I have the rattle whenever I'm doing anything less than 50. 50-ish seems to be the magical number where anything above it makes the sound disappear no matter what I do.....

It surely doesn't make any sort of rattle when I'm doing 105 ).

So, I don't think it's the motor mount. I might take her in this Saturday just for sh*** and giggles just because I actually DO think I'll have some spare time.

Now, that's actually more on the line of what I think I might have. I took it to the dealership last Saturday because I have the millennium plat service so they put me in a rental and kept it for the day. I called them - they got their tranny guy to take a look at it and he said that he couldn't find anything. Of course I don't know what all this means since the normal service guy I use wasn't there (the guy who lays everything out for me in a detailed way).

It doesn't seem to happen all the time. As a matter of fact, it almost doesn't happen at all after the vehicle has been allowed to warm up, but even that isn't guaranteed....it just tends to happen more when it's either cold or in the process of warming up. I've noticed, however, that if I have the sound when it's warmed up, I will ALWAYS tend to have the sound until I either slow to a stop or shift out of drive to neutral, rev the motor, and throw it back into drive (but even these actions don't guarantee that the sound will disappear).