The low coolant light first started coming on when it was leaking from the thermostat housing (that's been taken care of) and as I said before, I took a long road trip without seeing it again until this recent leakage/overflow/whatever it is. I've filled the reservoir twice but I will try it again today and see what happens. Thanks for the response.

 

Revisiting this thread... the leakage turned out to be the coolant elbows so I took care of that. Now the p0128 has recently shown up again along with p0125. This started soon after I started using the air conditioning. Can the AC be causing problems with the engine cooling system?

 

The P0128 code indicates the PCM detects the engine running too cool, and P0125 means there is insufficient temperature for the PCM to go into closed loop mode.

I'd take a look at the wiring that goes to the coolant temp switch for a loose/dirty connection. Did you install a lower temperature thermostat? Is the coolant ratio correct?

 

I checked the wiring the best I could and don't see anything that looks loose or corroded. The thermostat I used was OEM from the dealer so I'm not sure what the temp rating is. I'm using 50/50 coolant.


BTW, while these issues are happening the temp gauge doesn't move at all and the AC doesn't blow as cold as it should.


Yesterday I put more coolant in the reservoir and after a few minutes of driving the temp gauge went up to where it usually is and the AC was cold like it should be.


One thing I noticed is that the gauge not working and the CEL coming on happened when I turned on the AC before the gauge started moving, but during the test drive yesterday I waited before I turned the AC on and everything was ok.


Your help and advice is greatly appreciated.

 

Yesterday I unhooked the battery to see if it might clear any sensors that have been triggered. Since then when I've driven it I've let the engine get to normal running temp before turning on the AC and I haven't had any problems and no CEL. Could turning on the AC before the engine has warmed up be causing the problems? If so, is there a fix or do I just have to be careful about waiting to turn on the AC?

 

About a week ago it started making this noise:




It doesn't make the noise immediately on startup, but the noise starts when the engine gets close to normal running temp (when the temp gauge registers anything).

 

About 2 weeks ago I replaced the thermostat (again) along with the coolant temp sensor and so far I've had none of the cooling system-related issues (including taking a 900 mile trip) and the AC is working great. The only problem it still has is the squeal heard in the video above. Any idea what that could be?

 

Might be a long shot, but do you know if your belt is in good condition and tensioned correctly? Sometimes belts squeal when they have noticeable slack, are too tight, or are dried up. Check to make sure the belt doesn't feel super tensioned and make sure that it doesn't feel "floppy". After that, try spraying WD40 on the belt to see if that quiets down or completely removes the noise. If it does, then the belt is dry and needs some sort of lube. I've heard people lubing their belts with dielectric grease. Might be something to consider.

 

I had the coolant elbows replaced last October and they went ahead and replaced the belt then. I've tried the CRC belt conditioner and it didn't help. What puzzles me is that the noise doesn't happen when I first start the car cold, but I start hearing it after driving a few miles.

 

That's why I asked, sometimes they come like that. My belt for my Jeep came that way. I had to spray WD40 for it to go away, that's why I said it might be worth a try.