gixxer600

Hi all,

I was wondering whether or not it is normal for the temperature needle to move from the 1/4 point up to the 1/2 point and then fall back to the 1/4 point once the fans come on. The reason I ask is that I remember being told the temperature should always remain steady once the engine has reached its normal operating temp, unless there is a problem.

After driving about 20 miles at approx 80 mph on a warmish day, I exited the freeway and came to a rather long stop at the first red light. I noticed after 2-3 minutes that the temperature needle had risen to the 1/2 point. After the car started moving, it quickly moved back down to the 1/4 point where it usually stays. Once I got home, I left the car running at idle to make sure the fans were working, which they were.

I'm trying to figure out if it would be advisable to take the car in for a diagnostic, or if this is normal behavior. As mentioned, in my experience, once the car has warmed up, the needle does not move. This is regardless of speed, outside temp, etc.

Thanks in advance,
gixxer

ezone

You're right, it is acting odd.

The gauge is buffered, in that it reads about the same center position for a wide range of actual engine temps.

Grab a scanner or code reader that can give basic live engine data. (Maybe a Scangauge type setup?)

What is the ECT reading when the temp gauge reads 1/4?
What is the ECT reading when the temp gauge reads 1/2?

Once it is warmed up, the engine temp shouldn't drop under about 180.
If the ECT is dropping under 180 while driving after warmup, figure out why:

you may need a thermostat.
you may need to check the accuracy of the temp sender.
you may need ???

HTH

Matt_75

I can tell you I saw my particular vehicle(02 civic ex) do this once about five years ago after accelerating from a stop. It did it once and only once and it lasted about two seconds. To this day I can not tell you why it did it.

gixxer600

Hi,

Thanks for the replies. I took the civic for a quick spin on the freeway while actively monitoring the temp gauge, which indicated normal during the entire drive. At this point, would it be reasonable to assume the car is safe to drive? I am still somewhat undecided as to whether to take it into the shop or drive and keep a steady eye on the temp.

Thanks

mikey1

i would just keep driving it and see if it happens again

ezone

Yes safe, in that it isn't overheating.

Overheating does serious mechanical damage.
Running too cool "just" eats up fuel.