Firstly, Ive looked a lot all over the place, found nothing. Well, My engine runs strong, and the guage for the coolant/water temp almost reaches halfway. I've searched in here and people usually say my needles at the first line in the temp guage...well, mine doesnt have the lines. I have a old pic(1 month). The needle on the temp guage is a litter bit farther now...just a tiny bit, almost halfway. Right under halfway. Where should the needle be and how to fix it(as in fix, I mean get temps lower). New coolant/water/water wetter/(2 months old). Same thing with oem mazda thermastat. I have noticed its extremely easy to take off the temp guage reading wire connecter to the engine block with little force. here's pic. I guess im just paranoid...

year, model is in sig, stock 12a

 

At that temp it's fine. It's normal to go up alittle from there when in hotter weather. Does it climb when in stop and go or freeway?

 

When moving its usually right where it is in the pic. I'd say it might go a tiny bit up, but nothing much when on freeway or stop and go doc. Highest i've seen it is probably halfway.

 

You have me confused?
Under what driving conditions have you seen it near the 1/2 mark?
And was it cold, warm, or hot outside at the time?

 

the freeway most likely.. I noticed it two days ago. It's been pretty hot out lately. 80-85 degrees and higher

 

1st I would recommend cleaning the connections for the sender and tighten it.
One of the main causes of higher engine temps when driving at freeway speeds besides going up a hill is either a loose belt or a poor flowing radiator.
This is taken into account that the reading is correct. The t-stat is operating correctly. The radiator cap is good and the coolant reservoir is full.
Also if the timing was way off.

 

Ok, thanks doc. I might just get some belts, all three because some look like they could be changed. my coolant tank is full, New radiator cap also a month ago.

 

# of rows/core of your radiator can make a difference. Stock radiators are 2 rows whereas most replacement rads are 3 rows.

 

Does the "overheating at highway speed" problem get worse when your headlights are on? I have this problem too and I finally gave up on it before it drove me crazy:

Here's a good post on the "my temp gauge makes my car overheat" problem:

https://www.rx7club.com/showthread.p...light=overheat

Here's an amusing post on my efforts to run it down:

https://www.rx7club.com/1st-generation-specific-1979-1985-18/my-headlights-make-my-car-overheat-633150/

I think the conclusion drawn in the first post was correct, it is simply a problem with the gauge itself. I installed a second mechanical gauge to make sure I know what the real temperature is:

https://www.rx7club.com/1st-generation-specific-1979-1985-18/second-water-temp-sender-tip-installation-question-631760/

Another long post, but about halfway through I figure out that I need the mechanical gauge and find a neat way to put it in.

Good luck TT!

Ray

 

Thanks Ray, yes I saw that post about the headlights making your car overheat. My headlights dont make mine overheat though. Thanks for the links.

 

I think Im going to try the mechanical guage like you ray. Sometime when I'm not so busy.

 

That fixed my problem TT, as a rotary driver nothing makes you more nervous than watching the temp gauge drift into the hot zone. It turned out for me, the coolant temp is holding steady at 180 while the 22 year old stock temp gauge is dancing around when I'm doing 80 and the head lights are on. So it just makes me more comfortable to know it's something about the gauge, although I still want to know what's its problem.

And by the way, putting in that old school mechanical gauge was a lot of fun and not much work or money!

Ray

 

I'll have to focus on that when I can sometime ray. Great work. Thanks again.

 

I dont know if my guage is bad. I think tis could be good. I went to the top of the city last night just to look at it and after I got there, the guage was halfway probably, no marks like the 84-85. Opened hood and everything was hot. The radiator was extremely hot and the hoses were pretty hot too. The rad burned me from accidently touching it for like a second. My air filter was really hot too just from all the heat and I noticed my alternator is probably one of the hottest things in the engine bay. Basically, everything was hot.

 

Those temp gauges don't usually lie. Sounds like you got some overheating going on. But after you've driven to the top of a mountain stuff under the hood is going to be pretty hot even if everything is working normal (remember, we people operate at 37 centigrade, the engine likes it around 90 or higher). You really need to trouble check your cooling system.

 

Halfway on the gauge is not overheating.
And as rya has stated the under hood temps are going to be high after driving up an incline and I bet the outside temps in Vegas right now are somewhat warm.

 

Alright, ya, were already hitting 98 here. I want winter weather back now...lol. I'll have to try that temp thing you did ray sometime..just need the time.

 

thats normal.

 

The good thing about my mechanical temp gauge add-on is that it always reads a steady 180 degrees, in traffic, on hot days and even when my electric stock gauge is taking a walk on the wild side, like when I'm out driving after dark.

So I know I have an electrical issue, but not a coolant issue, which would be more serious. Putting that little Sunpro mechanical gauge in was the best thing I've done lately, now if I can just figure out why my car "overheats" when I put the headlights on.

Ray

 

Ya, that headlight thing is weird Ray...hope you get that figured out. You got the guage at autozone did you say??