Topic: temp gauge error and ac is blowing hot air

[pocketcthulhu]

so Tuesday i was running around 630 with the top up and the ac on, as always it was ice cold.
all of a sudden the ac goes from freezing to slightly cold to hot as hell...

i was flipping through the display looking for an error code and saw the temp gauge was showing ---
i shut the car off a number of times while i was out on lunch and it never threw a code or changed how it was acting, this was about 1:30

i left work at 5 and it was still acting up, about 10 minutes into the drive home the temp gauge woke up and showed 187, and the ac started working again.

i have an appointment today to curse and yell i mean have them look at the car

[smartin]

You might need to replace your temperature gauge. It's having an intermittent problem. Mine has done that.

[pocketcthulhu]

that's what i have been thinking.

[DeepBlueGXP]

Susan, do you mean the temp probe?

[smartin]

It could be the temp probe since you are the expert. But I have been told it's the temperature gauge acting erratic.

[Jackknife]

It could be the temp probe since you are the expert. But I have been told it's the temperature gauge acting erratic.

It'll shut off the A/C when it overheats.  Overheating may be due to a thermostat failing.

The car is an NA, so air bubble issue is less likely.

If the gauge and sender check out, my bet is the thermostat.

[smartin]

Thanks, Jackknife.

[Jackknife]

Thanks, Jackknife.

De nada...and, that may be how much my guess is worth.

[smartin]

Funny!

[DeepBlueGXP]

It'll shut off the A/C when it overheats.  Overheating may be due to a thermostat failing.

The car is an NA, so air bubble issue is less likely.

If the gauge and sender check out, my bet is the thermostat.

A thermostat is in the coolant line and that won't cause the DIC to loose the indications all together and then start working again.  It has to be the connection where the temperature sending probe is picking up the temp reading.  It's not making it to the ECM.

I'd go with either a bad connection or the sending unit, not the thermostat it self unless you notice temps running consistently hot and displaying such on a DIC

[Jackknife]

A thermostat is in the coolant line and that won't cause the DIC to loose the indications all together and then start working again.  It has to be the connection where the temperature sending probe is picking up the temp reading.  It's not making it to the ECM.

I'd go with either a bad connection or the sending unit, not the thermostat it self unless you notice temps running consistently hot and displaying such on a DIC

Actually, when my thermostat failed (the rubber gasket fell apart) the DIC showed ---

In my case the water temperature did not reach proper temp. in a set time and the DIC indicated this by going ---

[DeepBlueGXP]

Jack,  good info, thanks

[Gentleman Jack]

Jack,  good info, thanks

Any time Boss, any time...

[1LILNDN]

GJ  I think its the sending unit or Probe could also be a loose connection or ground.Thats just my  worth.

[Chemist]

"Alex, I'll take 'Thermostat Failure' for $1000."

[Fred]

Gotta agree with my brother Chemist. Thermostat failure. Been there and done that. 

[pocketcthulhu]

thanks for all the info guys, i went in for this last Friday and i was walking up the service manager warned me they were running Way behind, after an hour and i half of my car not moving i ended up having to leave and get back to work.

i have another appointment today, hopefully i will have better luck today.

[pocketcthulhu]

Song and dance time "we can't find an error code and we can't reproduce the issue"

feh im considering stopping off at auto zone and getting a replacement stat on my way home.

[KWhale]

Here's what I'm thinking, and I'm not mechanic, but I did sleep at a Holiday Inn a few weeks ago...so take this idea with a grain of salt.

First - the problem is the "coolant bubble" which is why your car ran hot the one time, and may not do it again for months.

Second - the Temp display showed "---" because the prove or sensor is only capable of sensing a max of xxx degrees.  Once it goes past that max it cannot send valid data to the display, so all you see is --- on the display.

Last - The A/C started to blow hot because the car is smart enough to know that when it's overheating or so hot that it cannot get a temperature reading any more, it stops the A/C from working.  OR  the A/C cooling coils were unable to shed their excess heat because the car was too hot which in effect, shut down the A/C.

Summary - One stupid cooling bubble causing many symptoms.  Verified by Dr Gregory House.


PS - Don't introduce your own cooling bubble problem when you swap out your thermostat Pocket!  Do a search here in Joe's Garage and I think you'll find the coolant change instructions that make sure you don't introduce air into your cooling system.

[DickW]

There is a TSB to put two valves in to prevent air bubles. I had it done to mine. It is a Warranty thing. If you do this be sure they evacuate any air out of the system.

[Jackknife]

Do you folks know that the OP has an NA.  They are not implicated in the "bubble" problem nor the various fixes (valves and otherwise).

It is the turbo cars that have had the problem.  I think you should look elsewhere for the solution...like the thermostat.

[Gentleman Jack]

JackKnife,

I'm leaning towards the Thermostat, what do you think?

GJ

[pocketcthulhu]

so it's been a fun three weeks with my ac going out at times and i have been unable to get it over the dealer ship when it's acting up so they haven't been able to find anything.

i kept telling them it isn't throwing a code but you know how the dealers are.

well yesterday just as i was finishing up shopping for motorcycle gear the ac went out and i was able to get it over to the dealership and guess what, it wasn't throwing a code.   so the tech started digging around and found some damaged wires (not really sure where as i didn't talk to him) but it was too hot for him to fix it and i had to get back to work, so they should have a loaner for me tomorrow so they can get this crap taken care of...

[pocketcthulhu]

just heard back about the car the sensors/wires/thermostat check out.

turns out the Saturn tech line told the dealer to replace the transmission control module, that doesn't really surprise me though considering i have had some Extremely sporadic downshifting issues over the past twoish years.

so they ordered a new tcm and armrest and should both be in about this time next week

[KWhale]

Right on!!  Fingers crossed that a new TCM fixes your problems.