Gmpower09

After driving a few miles the fan keeps running when the car is shut off and also my temp gauge doesn’t work when this happens. When it happens, I disconnect the battery and it all goes back to normal but a few driving cycles then it starts happening. Any ideas would be gladly appreciated.

6Speeder

Are you running a 160* thermostat? If so, just let it run and heat up for a minute or so before jumping up to freeway speeds. It isn't coming up to temp as fast as the computer expects and sets a "coolant undertemp" code. If you tune the car you can turn that code off.

If you are running a stock thermostat it may have failed open.

Gmpower09

The car is tuned and also has a 160 stat. It just randomly does it while driving it.

snomuncher

The fan is designed to run after the engine is shut off under certain conditions but it appears you might have different conditions (possibly introduced by the tune?).

https://www.corvetteforum.com/forums...post1595925872

Gmpower09

NO overheating here, fan goes on for more than 2 minutes and temp gauge stops working at the same time. Unplug the battery then it’s all ok for a few miles.

snomuncher

It might be worth checking for DTCs and/or checking for temp sensor issues. By disconnecting the battery you could be temporarily dismissing a code that reappears after a few start/stop cycles. A GM scanner should show a code history. Did your tuner modify any cooling fan settings?

Gmpower09

You’re right, I’ll give that a try and see if there’s and codes in the history. Thanks man!

6Speeder

It's the thermostat. Have your tuner turn off that undertemp code and you'll be fine.

FKING1

Same happened with my 160 (not an LMR), it's the problem.
LMR 160 works OK.

RottenII

Exact same symptoms here with my Summit 160 stat. The rubber around the edge was torn. U will need to replace the thermostat. Positive its not the tune.

Gmpower09

Hmm this makes more sense, due to having this tstat installed over a year ago and this just started.

snomuncher

Found this doing a quick web search, might be related to what you have experienced.

http://www.samarins.com/diagnose/p0128.html

0Billy@MTI

The p0128 code needs to be turned off.

BJ67

Even if the car was tuned, did the tuner make the changes regarding a 160 degree t-stat. Put the stock stat back in for the cooler weather and see you issue go away.

555ctsv

I had similar symptoms. The retaining clip to the temp sensor (below the throttle body, driver side) had cracked and the connector wiggled its way loose. Was very random because it was an electrical connection, so sometimes it would happen sometimes not. Id think a rubber gasket going bad would eventually cause the problem all the time. Might be worth checking that connector

carllangford

As I pulled into work this morning I noticed the coolant fan was running on HIGH and looked down and my temp guage is DEAD.... Shut car off and fan is still running... I guess a trip to dealer is in order here? Hoping extended warranty covers whatever it is.

RonC7

Sounds like a temp sensor issue. When the temp does not read, the car's computer makes the safe assumption that the car is hot and runs the cooling fans on full and cuts loads like the A/C compressor. Fault codes would confirm the problem.

Ron

Bill Dearborn

Chevrolet Protection Plan (GMEPP) will cover it if you chose the correct one. Codes will tell where to look for the problem.

Bill

carllangford

Protection Plan did cover it, it was a stuck-open thermostat.

gsc

Same problem, how do you get the fan to turn off? Been running for over an hour.