Yesterday I was taking it into work on the highway when I noticed it the temp guage was indicating over 210 degrees. I don't remember ever seeing it go above 210 let alone on the highway where it usually stays at 185.

My Z is mostly for recreational use these days, since I have a new daily driver. So it has been parked a lot.

While I was waiting to get through security at work. The temp went up to 220 -225.degrees. I realize that this is not critical. But as said before I have rarely observed the temperature going above 210 even when idling for a long period.

Checks have revealed the coolant is topped off. The top radiator hose is hot to the touch. So the thermostat seems to be working. Fans are blowing at idle. I also noticed that when I raise the rpms while parked. The temperature drops a little. But stays above 210.

The engine temperature appears to be stable. While commuting to work, it has never gone above 235. But as I said above, I can't recall ever seeing it climb above 210, let alone stay above 210 at highway speeds on a cool morning? My Z has 82,000 miles and is a '98. The bolt-ons in the sig have been on the car for a couple of years.

 

My guess would be that your gauge could be off or your thermostat could be sticking (closed) occasionally. That has been my experience when I thought my temp. was higher than normal.

 

the temp guage is a piece of crap......dont worry about it, as long as everything seems fine

 

Are the fans connected to the same relay teh guage is reading from? When I pulled in tonight, the temp guage read 225 - 230. I turned off the engine. The fans continued to run ( I don't remember that happening before). When they turned off the needle was just a tad above 210. The guage seems to be working.

However, how do you test the guage?

 

A shop can point a pyrometer at the radiator. I think I have the name of the tool correct, but it is a digital device that will detect the actual temp. of the coolant. You just point it at anything and it tells you the temp. I think these little devices are around $300. Your shop should help you for free.

 

This is why after 98 GM ran desensitized temp guages in f-bodies. 210 is pretty normal for a stock cooling system in summer around here. It is also normal for the coolant temp to rise 10*+ when sitting in traffic (fan drawn air isn't the same as cooler speed forced air flowing though the radiator).

Give your car a break. Its friggin hot out. Isn't SoCal having a heat wave too?

 

Actually it was in a heat wave. Lately it has been alright. Remember these readings have been while driving on the highway in the morning (before 7 am).

The fans do seem to be turning on and off as they should in accordance with the guage.

I usually have a short commute to work (12 miles). Then sit in line waiting to gain access to the Naval base where I work. I do not remember ever seeing the guage go above 210. It is usually about 185 while on the highway. I'm probably going to get it flushed later this week.

 

A flush won't hurt. When was it last done?
Get a 99+ model and it'll go to ~210 and set. Their temp guages only move in large increments.

 

Use a digital infrared thermometer. Craftsman makes a nice one for about $60 at Sears

 

The last flush was done about 3 - 4 years ago. The car has not been a daily driver for the last year and a half.

 

Turns out the thermostat was sticking. Thermostat has been replaced and the car is running like normal, between 185 and 210.

 

Hey, good guess dude.