shuts down while sitting in traffic, no sign of overheating.

[liz76]

bmw 325i 2001, after sitting in traffic for 15 min. and all of a sudden shut down, no lights came on, i went to restart it and it started, drove about a mile and shut down again. my temperature needle is steady at half way never goes past half when i put heat on it goes down. i think it is the thermostat, but am i wrong? is there something i may be overlooking? gas is full!

[Lord Vader]

Hard to tell what the cause may be, but I would check your coolant level and re bleed the collar system just to make sure theirs no trapped air pockets. I would also inspect your intake boot and all your vacuum lines to make sure you don't have a vacuum leak.

[liz76]

this only happens when i am driving for about an hour straight then sitting in traffic for about 15 min on a stand still then it starts putting and i give it gas and no response. then i have to restart it and sometimes it starts and sometimes nothing at all. so i leave it sit for at least 10 min and then i can drive but not for long before it happens again. sometimes it acts like it wants to go but like there is no gas or something. coolant level was good. what makes me think its overheating is the temperature gauge never goes past half way, and as soon as i put the heat on full blast it starts to go down and i dont have the stalling problem!