So first off the heat is not working. upon further inspection we found a reddish brownish sludge in the radiator cap. put in a new radiator, flushed the coolant system, flushed the tranny, flushed the heater core. Still no heat. this weekend we will be replacing the Heater Blend Door Actuator as we believe it is faulty.

Also just yesterday my wife informed me that after driving to the bank atm, she placed the car in park and it rev'ed up so high like she was pressing the gas pedal. (which she wasnt ofcourse) When she went to put it back into Drive it kicked and the RPM slowed down. She repeated this process (put it in Park and it rev'ed high, put it in Drive and it kicked and slowed down). After getting it back home she put it in park and it didnt do it.

Likewise while driving the work this morning, while at a stop light, the car just shut off. No puttering no choking, just shut off. It did start right back up however. But as she made it to work, about 15 minutes later, it did the same thing except this time it puttered off as soon as she pulled in her parking spot.

Car Guru'* please help!!

im going to guess throttle position sensor, not really a normal failure on that car but the only thing i can think of that would both make it rev and cut off like a switch. is it the regular 3800?

yes just the regular 3800 v6. the check engine light came on so after she gets off work we will be checking what code its saying. btw thanks for your advice

let us know what it is, that may narrow it down

ok will do. looking at other threads with similar issues, i have seen multiple ppl suggesting crankshaft position sensor or ignition control module to be the culprit. could these be possible? however before i work up from fellow counterparts into a heated debate im just going to see what the codes are...

ok J Dubb you definitely know youre stuff. the error code was definitely the tps. will be fixing that and the heater door actuator this wknd and will let you know my results.
thanks man!!

TPS sensors are commonly installed incorrectly. Have a looky at my video that shows how to install it correctly.

sure, fyi for future the icm and crank sensor are common for that engine. they shut off the engine when hot but wont give you any codes and will stop it from sparking.

ok good to know. i will keep that in mind if the problem persists. and thanks mike, VERY informative video!!

so the heater blend door actuator solved the heat issue. the tps seems to have fixed the stalling problem. thanks guys for all the help. now probably on to my next project...

putting a sway bar on my 2008 cobalt LT