smajicek

Hi, my 2014 z51 water temp on digital guage says 0 and on the analog the hand is at 100 which is the at the bottom 6 pm, I replaced my coolant temp sensor with an aftermarket sensor because dealer is closed and I still have the same issue. Start the car after sitting for hours engine cold turn it off after 1 minute and fan is spinning like crazy for 30 minutes. anyone experience this? could this be a thermostat problem? I cannot imagine so?

smajicek

Just thinking now if the thermostat is stuck open that would mean the engine would never reach its operating temp but would the temp gauge read 0 if thermostat is wide open and running coolant all the time with fans spinning 30 minutes after turning off motor?

RonC7

Does the oil temp on the digital display look reasonable? If so, not likely the thermostat.

The fan runs because the car's electronics don't see a reasonable temperature. The safe fallback is to assume the engine is hot and turn on the radiator fan.

There have been a bunch of similar threads lately. One poster noted that he had to disconnect the negative battery cable to reset the code and all was well. Disconnect for at least 20 - 30 minutes. You will only have to reindex the windows afterward.

Let us know how you make out.

Ron

smajicek

I just took it for a 5 mile drive and oil temp is 150 is that normal?

smajicek

This 0 temp actually happened to me once before about a month ago but it went away after several turn off and turn on motor doing errands, I figured it was a gremlin that went away, will try the battery disconnect next after the fan shuts off after I just drove the car.

RonC7

150 F is reasonable for a Z51 not fully warmed up. I see coolant temp rise to normal about 185F (2014 ran a bit higher) and oil temp will eventually track coolant within a few degrees. It usually takes at least 15 min to see oil warm up. Remember that there is 9.8 qts of oil in the dry sump engines.

So - I would disconnect the negative battery cable for at least 30 min, reconnect cable, reindex windows and see if the coolant temp starts to show a reasonable temp.

Ron

smajicek

Ok, problem solved, disconnected negative battery cable for 30 minutes, started engine and temps are back.
for those that love google.

Problem: C7 corvette water temp 0, fans run like jet engines for 30 minutes after shutting down a cold engine???
Resolution: Disconnect the negative battery cable for 30 minute, after reconnecting start the car and should be resolved, if yes re index windows.
This is the least expensive troubleshooting. I will now return the thermostat to the dealer to get $71 dollars back. The water temp sensor I purchased and replaced for $28 I will just leave it in, not worth my time removing it and returning it for a refund.

RonC7 thank you a million for your suggestions...

Elk

Lower window, hold in down position for 5 seconds, raise window and hold switch in up position for 5 seconds.

TJay74

Just to correct what someone said, even if the T-stat is stuck open the car will get up to temp eventually depending on the time of the year.

As said a loss of the coolant temp sensor that feeds the ECM will cause the fans to turn on for fail safe mode. I would bet the ECM had a stored code for the temp sensor, there are also 2 different codes the ECM has for stuck open/closed t-stat as well. Any of those codes will kill the dash gauge until the issue is resolved and the codes cleared from the ECM.

smajicek

So what you are saying if I understand my temp sensor was bad and replacing it was wise but to the battery needs to be disconnected for 30 minutes to reset code and get things to read correct? The $28 I spent on temp sensor was not wasted?

RonC7

Probably the sensor failed and the error was logged. It is apparently an error code that is saved and must be cleared with the proper code reader or power cycle.

We can't be absolutely sure that the temp sensor was bad without measuring resistance at various temps and comparing to the new one.

Glad the problem is solved.

Ron

VetteDrmr

See my recent thread on a similar experience:

https://www.corvetteforum.com/forums...fan-issue.html

HTH, and have a good one,
Mike

hisvett

I have had the same issue with my '16 C7 and my '17 XT5; what shows up first is a warning on the DIC that the Power Steering is reduced....also the A/C compressor will not engage, the cooling fans run on high and the water temp gage reads ZERO. I can clear it all with my OBD2 Scanner and everything goes back to normal for a while....a few weeks or months, before it does it again. Before I start changing out parts, I would like to know for sure just what the issue is.

VetteDrmr

Do you know which system you're clearing that puts everything back?

hisvett

Using my scanner I just use the "Clear Codes" and it does it thing. It takes about a minute or less between plugging in scanner in and hitting 3 buttons......piece of cake!

Last night I spoke to my nephew who is a service manager at a Chevy dealer and he said most likely the water temp sensor. He also said it's pretty common for them to die so I ordered one for each car.....they should arrive today.

VetteDrmr

Ok, thanks. I'm guessing the instrument panel system set some DTC that sympathetically set codes in the ECM, which drove the radiator fan to full speed. If it happens again I'm going to do a system by system clearing to hopefully nail that down.

Have a good one,
Mike

Avanti

Still sounds like a bad sensor to me... especially if you've left the aftermarket installed. I'd also suggest pulling the battery ground wire for 30-seconds and reconnecting. Can't hurt since the things are but 'puters on wheels. All you have to redo of consequence is your windows and the instructions are in the Manual. All the best.

TJay74

Pulling the battery cables will not reset the codes and hasnt worked since GM went to the Global A architecture. All codes are stores in the ECM and will pop a historical code until the issue is resolved and the code cleared. Some codes will self clear once the issue is resolved as well. Then the code stays in the history of the ECM for several drive cycles complete and then the code clears.

The codes are not part of the DIC at all, so OP either find the issue and fix it or else be OK with the code showing all the time.

TJay74

The instrument panel has nothing to do with this at all. The coolant temp sensor feeds directly into the ECM, the ECM gets the data 1st and then via the CANBUS system the ECM trips the check engine light when the parameters to trip the light have been meet. As we mentioned the fan is being triggered as a fail safe to insure the car doesnt overheat. Fix the issue that is causing the check engine light to trip and then reset the code.

VetteDrmr

Do me a favor and go read the thread I referenced in post #12 and see if you can provide me with some insight.

TIA, and have a good one,
Mike