Engine Overheat ... Coolant 256 degrees

[markirodriguez]

WOW I realize it is hot outside but I was NOT expecting my Camaro to overheat like it did ...

Coolant temp 256 degree's and started with the beep beep beeps for SHUT ENGINE OFF ...

Chevrolet picked it up right away and hopefully can figure out what in the world went wrong ...

[Silver Ice]

Wow, that's hot. Hope everything is ok.

[justa25thTA]

were your fans running?

[TC]

Mine did that a couple of weeks ago at the track. Super hot and had to make returns at about 5mph. I shut it off and let it cool down, fans were going- no steam coming out of anywhere?

Per the manual-
If an engine overheat warning is displayed but no steam can be seen or heard, the problem may not be too serious. Sometimes the engine can get a little too hot when the vehicle:

-Climbs a long hill on a hot day

-Stops after high-speed driving

-Idles for long periods in traffic

-Tows a trailer.

See page 9-25 for more info

[hypurone]

Holy sh!T that's hot! I am stunned the hoses or cap or even the rad itself didn't burst. Gotta be a bad t-stat or non-op fans. There is no other reason for that kind of temp (well, other than a bad head gasket allowing exhaust gases into the cooling system....)

[TC]

It seems funny that GM would say that it is fine, makes me think that they know they have a problem with false reading sensors?

[Cin]

Same thing happened to mine. The dealership kept it for 4 days checked everything and didnt find anything wrong with it. They told me to look in the owners manual and if it happened again to bring it back to them while it is doing it if no steam is coming out. So the answer is to let it cool off for a few minutes ??? I think thats unacceptable!!

[caligrown562]

My v6 hasn't got up that high but I have seen it around 230. Its usually between 195 205 while driving but while idling it goes up fast. Is it normal for these cars to run hot? The gauge by the speedo always stays in the same spot no matter what the dic says. Is it ok to shut the car off with it being around 220?

[SUX2BU]

Mine hovers at 180° in Texas' 108° traffic. I love my 160° thermostat.

[hypurone]

Originally Posted by SUX2BU

Mine hovers at 180° in Texas' 108° traffic. I love my 160° thermostat.

[Cin]

My car did it again yesterday! Granted it was a hot day, but why is it doing it? One thing I learned was that if you dont pull over and stop (was on the freeway, no shoulder) all the bells go off temp gauge pegs out, oil temp and transmission temp go up a little too, however, if I keep driving after about a minute or so all the gauges go back to normal. I went through that BS at least 8 times before it finally stopped. It's really pissing me off.

Called the dealership this morning, the guy said I should bring it in again and that he would make a few phone calls so maybe they can figure it out. Anyone got any clue about this issue? :(

[MMC]

May be as simple as the T-stat hanging up. Check the fans as well but at speed air flow should be enough through the radiator. If the oil temp goes up (as you stated)as well then it is actually a cooling issue not the sending unit. Just dont let the oil get cooked before it gets fixed or change it out. Let us know what they find.

[Cin]

My old style mechanic friends are saying the same thing about the Tstat or possibly a wiring problem. It doesnt throw any codes that indicate a problem when they run diagnostics on it.

I called the guys at Chevrolet.com, they set me up with a high volume service dept in Houston. The guy from that dealership is thinking electrical problems. Taking it in Wednesday morning. I'll let you guys know how it goes:(

[Cin]

Got my car back yesterday

I ended up taking it to my local dealer because It started doing it again while I was right down the road from them. Once they actually got to see what it was doing they agreed something was wrong.

They watched it go through the "cycle" and it even displayed the check engine light and still didn't throw any codes. With help from the technical assistance dept. they replaced the coolant temperature sensor and updated the PCM and BCM software.