Had a catastrophic idler pulley failure on the highway (didn't hear it...music) and finally noticed the engine light and TEMP GAUGE. After replacing the pulley and belt I noticed the expansion tank leaking from the cap??? I've driven about 50 miles and the temp is right smack in the middle...but i can smell some coolant. Well...tonight I had a 5 minute converstion at the grocery store (idling) and when I pulled away I smelled it big time. Parked...and I had a gusher!!! The coolant temp needle stayed in the right spot...??? Half and hour later I drove the 5 miles home no problem. Ideas?
Why didn't it show on the guage?

Help

 

The temp gauge on these cars may as well be an idiot light. They do not accurately measure temperature, rather they will sit in the middle of the gauge until they reach the point where the engine is overheating, then you will see the needle head north. If you have the chrono pack on your car then that gauge accurately reads the temperature. You can add an auxiliary gauge that will measure the coolant temp accurately, or use a scangauge II. Check your coolant level and find that leak!

 

Wow....you got the idiot light idea right. I got one of the PLX wireless ODBII devices that works with iPhone / iPads. Very cool and informative to ACTUALLY see whats going on in there. I was able to verify correct fan engagement by the degree and see the temp in varying conditions...thanks for the schooling!

 

Second on temp guage being an idiot light UNLESS you have the chrono pack...an oem option (big cluster of guages in middle, speedo/tach on drivers side.
You might want to get a compression check....you might have lost the head gasket from tge first overheat...might be pressuring the coolant syatem...and cauing the gusher...just a wag.

 

Since the Gusha I have replaced the Fan (no low speed) and the Coolant overflow (done in) At this point I have a correctly functioning cooling system verified with the scan guage. I have yet to take the car more than 10 miles away (hip surgery) but everything seems so far so good including a long idle test. I get a wiff of coolant after I park but can seem to see a leak. No white smoke, no yuck in the coolant or oil and great power so I'll keep my fingers crossed. Someone commented to me that the smell stays around after you've had a Gusha!

 

The smell could be from coolant on the engine itself from the overflow tank you replaced. It should go away after it all burns off.