Cause for concern? Yesterday was a really hot day was stuck in traffic engine temp was going into the red which I never saw before but the coolant was not overheating.

 

Sounds fairly normal...

Check your temp gauge against an infrared thermometer or something.

http://www.harborfreight.com/infrare...act-69465.html
http://www.amazon.com/s/ref=nb_sb_no...ed+thermometer

As CHEEEEEEP as these things are these days, there should be one in EVERY hot-rodder's toolbox, right along with the multimeter and fuel pressure gauge.

Would eliminate a lot of "noise" posts in this forum, too.

 

does the engine need to be shut down with the temp in the red if the coolant temp is with in spec?

That engine temp sensor is not in the greatest place in between the headers

 

Of course not. It doesn't look at the gauge to decide how to act, all it cares about is its actual temp.

How so? That's right where it belongs, where they ALL are; not sure how that isn't a "great" place?

 

id imagine it can pick up heat from the headers, throwing off the reading.


what temp is the boiling point of coolant mixed 50/50 obviously it changes depending on the mixture but generally speaking what temp does it boil?

 

Considering that its housing is screwed into about a 3/16" section of the casting, and that the actual sensing element itself is buried about an inch deep below that into coolant, not bloody likely.

Half & half coolant boils at around 240° at atmospheric pressure, and at around 270° at cooling system pressures of around 15psi.

 

How can the "engine temp be in the red and coolent temp be in spec"

you only have one temp gauge.

 

no the engine temp gauge gets its reading from the engine temp sensor in between the 2 front cylinders on the drivers side. that sensor does not touch coolant.

the coolant temp sensor is next to the thermostat in the manifold which does touch coolant but relays that info to the ecm only. you do not see that on your gauges

 

^ nope, you are incorrect.

 

not trying to be a dick but sorry bud im 100% correct.

 

all data info. as you can see there are 2 separate sensors

 

GM Parts Catalog

#78 Coolant Temp Sensor for ECM. Part Number 15326386

#46 Engine Temp Sensor for Gauge. Part Number 08993146



need any more proof?

 

No, I am not "incorrect". RONG, maybe; just ask my kids; but not "incorrect".

Furthermore, you are 100% INCORRECT on this particular matter.

The parts catalog doesn't show what's behind that hole.

The gauge temp sensor goes into the water jacket, through the 1/8" thick or so outer wall of the jacket, plus the 1/16" or so thick boss around the hole, and right directly into the coolant passage; right between the #1 & #3 cyls. Above the intake valve side of each front-to-rear, but of course over to the spark plug side side-to-side.

If you don't believe me, go pull it out and see what comes out from behind it; then when it finishes draining, look up in there and tell us what you see.

 

That's hat I was going to say, unscrew the "engine temp sensor " and watch the coolent run out.

The only sensor that doesn't measure liquid coolent temp is the air temp sensor.

The coolent and the cast iron will be within a couple degrees of each other.