Water Temp Gauge

[therock]

I HAVE A 99 FIREBIRD WITH A 3.8 ENGINE. AFTER THE
CAR HAS RUN FOR AWHILE THE GAUGE TEMPERATURE GOES TO 210 F. THE GAUGE TEMPERATURE DOESN'T VARY EITHER WAY FROM 210 F. TILL AFTER THE CAR HAS SET FOR AWHILE. I HAVE REPLACED THE TEMPERATURE SENSOR TWICE WITH NO CHANGE.WHEN I STICK A TEMPERATURE PROBE IN THE RADIATOR IT READS 20 TO 30 DEGREES COOLER THAN THE 210 F ON THE GAUGE. i HAVE NO PROBLEM ORDERING A NEW GAUGE IF THATS THE PROBLEM. CAN YOU HELP ME TROUBLING SHOOTING THIS PROBLEM? THANK YOU MUCH

[98Camaro3.8]

http://www.barryboys.co.uk/photos2/Caps_Lock2.JPG


What exactly is the problem? 210° on the gauge is about normal for a stock thermostat. The temp gauge is also pretty inaccurate...hook it to a scan tool to read the actual temperature.

Originally posted by therock:
WHEN I STICK A TEMPERATURE PROBE IN THE RADIATOR IT READS 20 TO 30 DEGREES COOLER THAN THE 210 F ON THE GAUGE.

The coolant is supposed to be colder after going through the radiator...that's why it's there.

[ January 10, 2006, 07:18 PM: Message edited by: 98Camaro3.8 ]

[therock]

I understand its going to be colder but not by some 30-50 degrees and also i forgot to mention before my fans werent coming on. I figured it out because my hoses kept on popping off but my gauge was reading 210. So i let it sit started in the driveway one day for about 15 mins. When i came out the radiator was bowling over, and the overflow tank was hissing but the gauge was still reading right on 210 so i know it was way off. So i am wondering is there a module that goes with are gauges that runs to the pcm ive been reading up but theres not much info????

[J. Henley 17]

Mine stays around 160 (or 180... whatever the first number after the first line is)... it occasionally will rise and fall in traffic on hot days, and it would really heat up in hard turns before I figures out I was low on coolant, but 210 is abnormally hot for me.

Also, mine doesn't stay still like that, it almost constantly changes sometimes.

[98Camaro3.8]

Originally posted by J. Henley 17:
Mine stays around 160 (or 180... whatever the first number after the first line is)... it occasionally will rise and fall in traffic on hot days, and it would really heat up in hard turns before I figures out I was low on coolant, but 210 is abnormally hot for me.

Also, mine doesn't stay still like that, it almost constantly changes sometimes.

That's normal too. These water temp gauges are horribly inaccurate. What's normal for one person's car is different from others'.

Originally posted by therock:
I understand its going to be colder but not by some 30-50 degrees

So is it 20° or is it 50°? Little bit of a difference there. ;)

If it's that much colder, it still sounds like it's running normally depending on your thermostat and the accuracy of the gauge.

Originally posted by therock:
and also i forgot to mention before my fans werent coming on.

Cooling fans shouldn't turn on until 221° or when the A/C is on.

Originally posted by therock:
I figured it out because my hoses kept on popping off but my gauge was reading 210. So i let it sit started in the driveway one day for about 15 mins. When i came out the radiator was bowling over, and the overflow tank was hissing but the gauge was still reading right on 210 so i know it was way off.

Here it sounds like it's overheating, but you say it's up to 50° colder than 210°...which means it's running right where it's supposed to.

It may do that if you leave the cap off. The whole system is supposed to be under pressure. With the cap off, the boiling point will be much lower, and the fluid could expand to the point that it overflows out of the cap opening.


Get the gauge out of the equation. Hook it up to a scan tool and see what the temp really is. If that's out of whack also, then you know the problem isn't the gauge.

[therock]

Thanks 98 camaro for your input and advice ill try the scan tool as soon as i can. But when the water was boiling over the cap was on and we let the car cool down and the water was reading 245 after having 5 mins to cool down. So this is when i figured something was way wrong. First if it was that hot why werent the fans coming on? Why wasnt the gauge reading up to there? Something has to be tied into this i have mad a manual fan switch for know and the hoses have stayed on so far. But the car still reads the same temp 210 with the fans on high. But i check the water and it reads usally 160-165. Im sorry f this is confusing its really hard to write the prob becuase i just dont know what really is the prob is it the computer the gauge the wiring ???? Who knows