First and Foremost, Hello! new to this forum. Im a member @ LS1tech and a few other forums for cars I currently own.
Having issues with my g/f's car and hoping you guys can help?

Its a 2006 dodge stratus sxt w/ 2.7l v6
First issue was no heat, so i changed the t-stat, then noticed a leak at the upper water outlet that housed the coolant sensor so i replaced that as well. Autozone had gave me a bad sensor and that caused me thru a lot of hell untill i once again swapped that part out again. (Car wouldnt start) Everything was fine I thought for about 3 weeks and then she told me her check engine light was on. So i scanned a p0128 (Coolant temp BELOW t-stat regulating temp. She had also mentioned hearing bubbling coming from the car (coolant boiling in overflow resovoir) Took the car out with me tonight and outside was 40 degrees. I was on the highway going about 75 mph for about 10 minutes, When i got off the exit i noticed steam blowing from under the hood at the rez so i jacked the heat to full to get where i was going. Temp was at normal on the cluster. When i had the first c/o sensor and housing it would overheat and not budge from cold mark but maybe a 1/8" I got to where i was going and the coolant was all over. couldnt find where it was coming from but it looked like it had came from around the rez but not from the overflow tube? I am lost for what to do now? The research i did for the code said it was either iat, coolant sensor, or t-stat. 2 of 3 have been replaced. one being replaced twice. I dont know where to go from here except change the pressure cap on the rez? the fans seem to come on and off normal and maintain temp according to cluster? Car has 86k and im ready to trade it in!!!! If i dont get this corrected ASAP then i have to pull my GXP out of winter storage for her to drive which i obv. dont want to do!!!!!!!

Another bit of info on the car is, I snapped a upper intake manifold bolt at first upper housing c/o. So I replaced the lower manifold with one from a sebring from a junk yard. All numbers were the same except one or the other had a 0 before the rest of he numbers. They looked identical? Lower and upper were installed with new gaskets, proper torque pattern and " lb.
Any advice out there?

 

welcome to site, when you replaced outlet did you bleed cooling system of air,here is a list of possible things to checkPOSSIBLE CAUSES

• Good trip equal to zero
• Low coolant level
• Other possible causes
• Signal circuit shorted to battery voltage
• Monitor engine coolant temperature
• Temperature sensor voltage below 1.0 volt
• Signal circuit open
• Sensor ground circuit open
• Signal circuit shorted to ground
• Signal circuit shorted to sensor ground
• PCM low
• PCM high

don't know about autozone outlets but read where the ones advance sold had alot of problems ,changing the manifold probably isn't causing your problems, if you ever have to change outlet again you can use a flex-head ratcheting 8 mm wrench to get that one bolt out without taking off upper manifold

 

The new sensor came with 10 mm bolts heads and the flex wouldnt fit, i did modify a 8mm to remove it the first time.

Update on car is it will run perfectly fine with no coolant boiling or steaming in city driving or sitting. It seems to only boil over when getting off the highway? Its the only time the car has any issues, and still stays right at norm hash mark on cluster.

It does appear that the coolant sensor takes longer to warm up though than before. So Im once again stuck between the t-stat and the coolant sensor which are both pita's to change. The only other thing i have came across was a possible head gasket issue allowing exhaust to pressurize the coolant sytem and lower the boiling point but i assume it would then boil in the resovoir at all times?

What scanner would i need to use to test the circuits from the pcm to the sensor's to check for grounding issues or a bad sensor?

Im at the point now where i just want to do a compression test to rule the possible head issue. The car has only overheated 1 time to my knowledge with the original from factory sensor reading Hot! and that was due to a leaky water outlet / low coolant combo

I think this 2.7 is the worst car ive ever had to work on as far as part locations go. If it were mine id light it on fire.

I did bleed the system through the bleeder at the top water outlet when i replaced it. I also added my coolant through the sensor bung before i installed the sensor. i then jacked the passenger side of the car up and removed the res cap and let the car warm up ( old school bleed)

 

most tests needs a drbIII scanner(mainly dealers have expensive ) can probably check wiring/sensors with a regular electrical meter don't know if there the same have diagrams for an '04 2.7 showing what each pin is for on pcm connectors.Yes they are a real pita to work on

 

Would love to have that diagram, !

 

did you still need diagrams haven't had time to get online last few days .if so send me a private message with an email address and i will send what i have , they never work when i try posting diagrams on here they change every time you open them to something entirely different from what you expect