Engine Temp Gauge
 

Lately my engine temp gauge is reading VERY LOW. Meaning...

What I mean is that after running the engine for 15+ minutes the gauge isn't even reaching the half way point, sometimes not even a quarter of the way.

Now I know something is wrong... Possibly a sensor somewhere is jostled around or something.

What are some possible culprits for this happening?

Thanks in advance.

I would check the thermostat. My guess it that is bad. I will also bet the heat is acting funny.

Try changing the thermostat and see if it fixes the problem, very cheap and easy to do so i would try that first.

FYI, gauge was working fine today...

I am thinking it got pretty cold pretty quickly outside and then today it is back in the 60's.

it was awfully low when it was cold outside and fine today.

Would still change the t-stat. A engine that warms up slow and does not reach it's proper temp will not preform as well, use more gas, and wear out part.

BTW, how fast should these 2.3,4,5 motors warm up? My 850 takes about 5 to 7 minutes while my 960 is there in 1/2 the time.

I tried the heat today and it seems to be warm at 80 degrees but the center vents seem to be putting out warm/cold air...

Yeah, change the T-stat. That sounds like the problem to me.

And these engines should only take about 5 or so minutes to warm up (which is incredibly fast... most cars take twice that or more. My wife's Jetta takes about 7 minutes of driving just to start putting out heat, which is typical of a 90s VW. My S70, on the other hand, is putting out heat by the time I get to the end of my street... it still amazes me after 2.5 years.

Well I called my dad to make an appointment for my car at home and I told him the problem.

He said what does the COOLANT level look like? I said I hadn't checked, so I went and checked. It was close to the MIN mark on the tank.

I didn't have any coolant so he said to use WATER. So I let the engine cool down for an hour and then I put water in the tank...

I let the car sit and run and wouldn't you know the engine temp gauge went to NORMAL in the middle of the gauge between OVERHEATED and ENGINE OFF...

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Now my heat was acting funny too. It felt like cool air was coming between the middle two vents added with warm air. Well I looked and my A/C was still on so I turned that OFF.

It felt a little warmer, but not as warm as it could be. Then I see a little dial next to the vents that has a little blue arrow pointing towards a small person image. I turn that all the way down and test the heat from 72-82. And the heat works wonderfully it seems.

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Now my test for both of these things is tomorrow morning when I go into work. it should be down in the 40's to upper 30's and that is when my engine temp gauge really wouldn't budge past a 1/4 of the way.

If it goes to the middle of the temp gauge then I should suspect it is a coolant issue and then just add regular coolant to the tank after that.

If it doesn't go to the middle of the temp gauge then I will suspect T-Stat...

Your thoughts?

Low coolant level won't cause the gauge to read low. Your dad may have thought the heat issue was caused by low coolant... but for you to lose heat (because no coolant is circulating in the heater core) you would need to be dangerously low. There would need to be nothing in the bottle for it to affect heat output.

The dial you turned is an "air mix" dial. It allows cool outdoor air to enter without passing through the heater core. Good for really sunny, but cool days, when you're hot up top and cold down below. If the temperature problem persists, change the thermostat.