hi, My 2005 Monte Carlo LS 3.4 has been shifting poorly ever since i changed my Thermostat and Temp sensor while trying to fix temp gauge that bottomed out and no AC last week. anyway, i had to remove the throttle body to get to the t-stat. after i replaced everything and put it all together a new problem arose. my car now shifts very poorly around 40 to 50 mph. the longer i drive the worse it gets. it feels like pressure in the tranny fluid lines get higher and higher. i thought i had a possible vacume leak around the throttle body somplace so i took it to a mechanic but no one seems to be able find one. No engine or transmission codes were found. I've made the following repairs to no avail.

1) Changed the TPS
2) Changed the Coolant sensor and Connector
3) Cleaned the MAF
4) Cleaned the IAC
5) Cleaned the throttle body
6) Flushed Radiator

well this morning a check engine light and code came up.... finally! It was an IAT sensor. the autozone printout read "1) check wiring 2) replace sensor". it made sense, i could have damaged it while removing the intake air tube and not pulling the connector off. i checked the wiring and it looked ok so i got a new one and reset the code. it did'nt do any good. i just now temporarly wire nutted in a new pigtail connector i got at the junkyard but i hav'nt tried the car yet. am i just so tired a fooling around with this. the mechanic seems to think it's transmission but why would this problem arise immediatly after making the thermostat repair. anyway the temp gauge still bottomed out 2 times even after changing the thermostat and temp gauge. could all this be traced back to the car computer? or possible even a bad resistor somewhere??? or even a bad car ground????

Also, I think my coolant is a bit low with air in the lines. because i hear it when i drive sloshing around. I made a repair a few days ago and some leaked out and i did'nt replace it. My question being. would Low coolant cause any of these symptoms. perhaps air and not coolant reaching the coolant sensor on the top of the engine? i had it filled pretty before but it still could've possibley had an air bubble in the radiator.

sorry bout this being so long, i just wanted to be thorough. and will hopefully get some insight as to what the problem may be. thanks! joe c

 

i did'nt clean the IAC like i stated above. just the MAF