I've had my car back for 2 weeks ( after a cam upgrade ). it's been running great and actually been running cooler too.
previously, on the freeway it'd be around 198°F, stop & go traffic around 210°F-225°F.
during the cam install, the shop noticed that some of the under hood wiring, was showing some wear.
he re-soldered 7 of 8 fuel injector pigtails and a few other sensor connections too. it appears that one of he sensors
may have been for the coolant temp. since I got the car back, the coolant fans were coming almost constantly.
car was running between 198° - 201°m freeway, around town, stop & go.
Saturday, while stuck in stop & go traffic, I noticed the temp gauge running a bit higher than 'normal' @ 203°.
then I watched it climb to over 230° in about 30 seconds.
I pulled off the road and sat for an hour, waiting to cool down and traffic to subside. when I did get back on the road,
it went through the same cycle, but at least traffic was moving some what. still running hot ( 220° ).
when I got to the freeway, I did a 40 mile run and it didn't get past 198°. come to a stop, and it starts climbing again.
on the way home, on the ride home, got stuck in some more traffic, with the temp going over 250°. got all of the bells & whistles going off (HOT! COOLANT OVER TEMP! TURN OFF A/C! ). I was into the red on the gauge. the overflow tank was steaming like a geyser! had to walk a 1-1/2 miles to find some coolant. dropped in a gallon. by then the traffic was gone and,. I was able to head straight home ( 60 miles @ 75-80mph ), again running @ 198°. get off the freeway, temp starts to climb. go out the next morning. small puddle under the car ( low coolant ).
sorry for the long note, but just trying to work this out. how am able to drive on the freeway, for an extended period of time, with the temp remaining the same ( no variance at all ), then stop and have the temp rise that fast?
if I was loosing coolant continually, I would expect the temp to rise even if on the freeway. airflow by itself, can't maintain a consistent temp. I'm trying to get it into a different currently for an inspection ( one that I trust ).
also, not sure if or how it's connected, but I picked up a CEL ( P1174 ) too.
again, sorry for the extended note, just venting a bit., when I get this addressed, i'll be thinking about selling it.
I do love it, but my previous ride turned into a 'whack-a-mole' and I don't want and can't afford another one.

 

Did the car do any of this before the cam upgrade?

Can you hear the fans come on?

 

prior, the car always ran about 198° on the freeway, 220°-230° in traffic.
after cam install, still 198° on the F/W, but never over 201° ( regardless of traffic condition ). I know it's a small sample size, but still...
previously, the fans only seemed to come on once I turned to car off. I'm guessing that there are 2 fans ( ? ) and maybe only one was working before and I couldn't hear it ( ? ).
after the cam install, the fan(s) would come on regularly. Saturday, I did not hear them come on.
I have to drive it about 1-1/2 miles to the local shop and, hoping it makes before the temp spikes again.
it's got to be the fans but, it just seems weird that the temp would stay the same on freeway, with no variance.
if it's just the fans, great!

 

check the fan connector passenger side behind the radiator, it could be center wire burned out in the connector stopping fans coming on. Happened to me, I replaced the connector, happened again so I hard wired it and no issues since. When I was on the freeway, I could get the temp down just by the amount of cooling air flow coming into the engine compartment, but when in traffic temp would spike and alarms going off.
adding link
https://www.corvetteforum.com/forums...three-pin.html

 

At freeway speed you have sufficient air flow to keep a cool temp for the coolant. Once you slow down the temps will rise rapidly if your fans are not working.

Have you looked at the fan connector? They have been known to overheat and melt under high fan usage.

GL, hope it's an easy fix. I believe it will be.

 

I'm pretty sure it's fan related. do you know if it has 1 or 2 fans? while the car ran on hot side before, I don't remember hearing the fan(s) come while sitting in traffic. so if it has 2 fans, maybe it was the right side one working only. since previously it would max out around 230°. before Saturday, when I could hear the fan(s), it would max out 201°.

 

pretty sure it's fan related. just need to figure out if it's wiring, coolant sensor or, the fan itself.
I've only it for a few weeks and, love the new cam but, as she's now got almost 160k miles on her, I don't want this to be the
starting point of the domino line. if it's easy fix, fine. if it leads tom more issues, then I've some decisions to make.

 

Also happened to me on my 2012 GS, fan connector melted so fans could not come on. Replaced connector, now about 2yrs. have passed and no problems. Very

 

I have a dewitts radiator and 1 fan. The fan connector is easy to check you can reach it on passenger side from up top,

 

hoping that it's a simple as that. before I got my car back from the cam install, I was wondering about how it might affect the temperature. imagine my surprise when it actually cooler. granted, it was due to some wiring repairs.
and that's where I'm at currently, waiting to confirm with the mechanic what wiring he re-did. while it did allow for the fan(s)
to fully operate, now they are not.

 

Not saying your shop did this but....

A lot of shops will try to run the engine much cooler that it should be, including adjusting the tune to turn on the radiator fans too soon, and ramping the percentage too suddenly, or too high. That draws a lot more amps though that plug to the controller than really should be. Too many amps through a plug not rated for it more often than not the results in a melted plug, no more fan, and an overheating issue when not moving at highway speeds.

First thing to do is check that plug on the radiator leading to the fan controller. Unplug it and look to see if there is indication of melting inside of it.

 

that's the area where i'll be focusing on. I also need to have the mechanic let me know, which sensor he worked on ( smoking gun? ). any connection this issue a P1174 CEL? car seems to fine. this CEL came on a day or after the cam install.
the overheat was two weeks after. as one possible cause was clogged or non operating fuel injector, I checked the exhaust
temps on manifold ( with an infrared thermometer ). three were at about 215°, one was about 198°. these temps were taken from the heat shield on the exhaust manifold ( drivers side only ).

 

What did the shop say that did all the work and all the wire repair. Seems like they have something to do with the problem.
why aren’t they working on it and not you?

 

P1174 is fuel trims, bank 1. I am assuming that whoever did the cam did tune it afterwards. Am I right?

 

it's weird in that whatever wire repair he did, caused the cooling fan to work properly. up until it didn't.
as I no longer have a garage of my own, I'm limited to a carport with minimal lighting.
i took a chance on the repair. the tuner I've used in the past, knew someone who could the work.
the only issues is / was, that he is 70 miles away. I talked to him today and he offered to look at, if I can get it to him.
I did have AAA tow it out to him initially. If my local shop can't or won't look at it, I may using AAA again.

 

your car has 1 fan only unless some one modified it

 

thanks for the info! I'm going to try and take a look tonight and, see if anything is obvious ( loose, worn or, burned wiring ).
I'm hoping to be able to make the 1-1/2 mile ride, to the shop this Thursday.

 

Could cooling system have air trapped in it?
Only reason I say it's possible is because of recent cam install.
Otherwise if not air or burned connector, likely in tune.

Dealing w/ a similar issue w/ my Z06 after a cam install now, though no overheating.
Noticed fans coming on when they never used to, pre-cam.
Thought it had to be air so had it checked, not trapped air.
Thinking my issue's w/ tune.

 

not sure about any trapped air as, it ran great for two weeks ( 500-600 miles ). but since the fan was not working when
it overheated, I'm betting it's the connector that's the issue. all a guess for now. i'll do a little more investigating tonight.
otherwise, to the shop it goes!

 

2 minutes with your cell phone flashlight will tell you. If it's melty you can't miss it. Unplug it, look inside, You'll see melted plastic and ozone around the middle terminal.