Stalling, bucking, heat coming and going...

I've posted on here many times but didn't want to add this issue to any of my other posts because it's not totally related. I have a 2000 V6 with about 150K Miles.

Just got the car back yesterday from getting a new starter. Still won't start without needing a little bit of gas. Drove for a while to go get my friend so she could drive it home for me since I had a loaner I had to drive also. Car previously had misfire issues. I was driving on the highway and me heat was coming and going, like it was blowing really hot and then would be blowing really cold. I checked the coolant while the car was hot and it was around the cold fill line in the tank, so I topped it off. Didn't really notice any more heat issues but don't think level was low enough to cause issues.

Second problem is that it felt like it was still misfiring going on inclines mostly but it also happened on flat ground and in the city (Last time the issue was ONLY on the high on inclines) but it didn't feel like the same feeling it was previously when I had this problems. Last time it was like little hiccups, last night it was violent... so violent I refuse to drive it back to work today because it scared the crap out of me.. I'd be cruising around 70mph on the highway in cruise control (just trying to get her home) and it would "buck" (Only word to describe what it did) and the RPM's would go down to around 200-300 and then bounce back up and it kicked the cruise control out. This happened while I was in the city just driving around also and the car stalled twice in the city.

SES light is on but I haven't gotten it to the mechanic yet to check the codes. He can't see me until after 1:00 PM so I thought I'd do some research on my own. It's similar to the issues I was having a few weeks back but it was a very different feeling and much scarier.... help!!!

Best to scan for the DTC codes and then post. Did you ever get the LIM gaskets replaced? The bucking is called fishbite or chuggle and could be TCC related but a misfire condition will cause it.

Thanks for the reply. Took it to the mechanic. Code was for Crank Shaft Position Sensor. He said it made no sense and cleared the code and said drive it around and see what happens so I drove around for about 2 hours, about 85 miles in total on both city streets, country roads and highways, and the car did not do one weird thing. It's so confusing.

What exactly is TCC? I'm not familar with that term. At this point my mechanic has no idea what could be wrong with the car since every time I seem to bring it to him it is running perfectly. Any more insight would be great because its all just so odd and I really don't want to miss any more work over this. Thanks

Also, does this mean that if I stay off the highway and keep to back roads that I should not have any problems. This isn't the best time for me to be without a car and I'd really love it if I could just stick to back roads and know I'm OK. Also, would this cause the Crank Shaft Position Sensor to come on??