[cellsafemode]

Originally Posted by ctrlz

What is the best way to clean this?

I have not heard of this. I wonder if it is from using tap water added to dexcool. Could be a salt precipitating on the back side of the 'stat. Maybe vinegar to clean it?

no, it's just dexcool. I got some pics in the diy thread you can check out.

https://www.camaro6.com/forums/showthread.php?t=592211
(edit: yes, the pics are of the v6 t-stat...but it's the same issue in the v8 t-stat)


this is the same kind of surface film anyone familiar with dexcool would recognize. Nothing really new there as dexcool has been doing this since the beginning. The only difference is old dexcool would eat gaskets too.


To clean it, i'm not sure what you would want to use to dissolve it without using an abrassive action of some kind. I could try some things, i still have mine out and uncleaned.

However, if it was very easy to get off the surface of metal, there would be some known remedies for getting it out of radiators and such in threads from previous horror stories of older formulations of dexcool really caking on the entire coolant system of cars. I dont know of any flushes that remove it from the surface. but since this is just a t-stat, some other solvent options may be available that do work (like dipping in gasoline etc)

[jcabbott86]

Ready for a brain scratcher? Here's my issue.
Minding my own business driving to or from work and my coolant gauge drops to min. Fan spoils up.. Reset error codes.. Its goes back to normal op..
But here's mind boggler... It happens within a 1/4 mile of the same spot everyday..

at first i thought it might be some kind of RF interference.. but more people would have the same issue. At this point idk wtf is going on.. I've changed the sensor out.. wires looked fine.

[arpad_m]

Originally Posted by jcabbott86

Ready for a brain scratcher? Here's my issue.
Minding my own business driving to or from work and my coolant gauge drops to min. Fan spoils up.. Reset error codes.. Its goes back to normal op..
But here's mind boggler... It happens within a 1/4 mile of the same spot everyday..

at first i thought it might be some kind of RF interference.. but more people would have the same issue. At this point idk wtf is going on.. I've changed the sensor out.. wires looked fine.

If you always drive the same route, it may not be the location that's relevant but the time elapsed, and by proxy, engine temperatures reached.

Just a conjecture, but since you replaced the temp sensor, let's assume it was not the cause, but it could also be the thermostat opening too early, triggering a code that then causes the failsafe logic to kick the fan into high gear, which then quickly drives the coolant temp down and the gauge backwards.

I'm not a mechanic, so what I would do is replace the thermostat, clear the code(s) and hope for the best

[grampa_ss]

That happened to me. New thermostat resolved the issue.

[ctrlz]

Originally Posted by jcabbott86

Ready for a brain scratcher? Here's my issue.
Minding my own business driving to or from work and my coolant gauge drops to min. Fan spoils up.. Reset error codes.. Its goes back to normal op..
But here's mind boggler... It happens within a 1/4 mile of the same spot everyday..

at first i thought it might be some kind of RF interference.. but more people would have the same issue. At this point idk wtf is going on.. I've changed the sensor out.. wires looked fine.

2016... How long has this been happening?
My wild guess is thermostat is sticking. When coolant gets up to temp it pops open too far, sticks again, then gauge reads dropped temp. ECM sees this as a fault, and sets the fans to high, which I believe is the "failsafe" mode.
Happens at the same place because that's where you hit that coolant temp on your route. You might be able to see signs of this on the digital gauge if I am right. It should climb pretty normally, then drop quickly before it bottoms out.

[Max_Burnside]

Had the same problem on my 2017 RS V6. There was no reading on digital dash gague and zero reading on the analog type gague on dash. Problem was the thermostat which aftermarket dealer warranty covered. Mostly covered. I got $600 off an $800 job (with my $100 decuctible it cost me only $100 extra).

These problems are usually the sensor or the thermostat. Sensor replacement is cheap and you can do without taking everything off. If that doesn't fix it, then its a faulty thermostat. They stick sometimes or just fail somehow but either way the thermostat replacement is the second thing to try.

I know the thermostat is not digital so it can't fail due to RF interference since its mechanical in nature.

Like someone said, if its same spot it's distance driven not location.

If you sense a temp reading then it goes bad, its because thermostat failed to open causing a logic error in the computer because thermostat and sensor don't "match" giving you a visible error to the driver letting you know something is wrong. The sensor not only senses temp but also if the thermostat is open or closed at appropriate temps.

Have a mechanic read the code but if you sense a temp on start up, its not the sensor at fault.

[easttxss]

When the thermostat sticks open, even just a little bit, it takes the engine longer to heat up. This triggers the code and the computer drops the gauge to zero and turns the fan on high. This has been discussed many times on here.