[Shotimes] Problem - My '95 MTX runs really rough when the engine temperatur e goes up.

[MFevre@cedco.com]

Hi All,

When the gauge reaches the upper middle section of normal, (i.e. the
indicator points to the "O" in "Normal" on the gauge itself), my car has
taken to running really rough, lurching a bit as I gas it. The "Check
Engine" light may or may not come on, but it never stays on, and as soon as
the engine cools down a bit, everything is fine, and the car runs like
nothing has happened. 

The funny thing is, my car has always run on the cool side. On the open
road, the needle usually stays just a hair's breadth above the blue "cool"
indicator, and in heavy traffic, the temperature gauge has gone up a bit
more, but things usually remain well on the low end of normal. Lately,
though, the gauge seems to be going higher, and then I run into this
trouble. 

I'm due to flush out and change the coolant anyway, but I think something
else is happening here too.

Anybody have any thoughts about what might be going on here?

Thx!

-Marc
Napa, CA