ok, NOW what's wrong...

[sirslex]

somebody help me out... either point me to relevant info (that I don't seem to see anywhere[probably due to me being an idiot]) or just tell me what it could be...

Anyway. After swapping in a new(er) engine, after I drive hard even briefly the temp gauge almost always shoots down to cold.
That's not supposed to happen is it? I almost think it could be miswired somehow, except that it always starts out cold and takes a bit to warm up(as far as what the gauge shows anyway) and when it's warmed up it shows a little below the middle of the gauge. And when I get back in after it's warmed up, it shows that it is in fact still warm.

....sigh...

bad thermostat or some other sensor or....???

Thanks in advance

 

[dsmrollerz90]

My 93 1.8L Eclipse used to do this, I tried changing the thermostat, did a full rad. flush. I tried everything, nothing worked, I just stopped worrying about it, atleast its not heating up.

 

[talonted 1g]

do u still have heat when the gauge goes down to cold?
could just be a faulty gauge

 

[sirslex]

do u still have heat when the gauge goes down to cold?
could just be a faulty gauge

actually, to be completely honest, the heater doesn't get very warm anymore.... well, except for the other day when I took the vent cover off on the carbon fiber hood. then it got pretty warm in the car as well as being able to see some good "heat waves" coming through the hood.

I don't suppose these two issues are related though are they? I mean as far as temperature inside the car everything seems to stay the same while the gauge reading drops.

 

[Alan11]

As long as it doesn't overheat its fine, but fix your gauge to make sure it never overheats..could be the temperature sensor...and if it after an engine swap it could be a wire or something..not your thermostat nor your head gasket..this is not a mechanical problem its electrical...
correct me if i am wrong..

 

[Hi-PSI99GSX]

If your heat isn't working please check for coolant level. My reservoir was at the max line but bone dry at the water neck. Heat will blow out cold instead of hot, it also can cause serious damage if you are driving without coolant in the engine. Hope that fixes the heat, as far as the gauge dropping check your coolant temp sensor to make sure its running properly.

 

[rhartwickjr]

Yeah no coolant resulted to blown motor, but it happened in matter of seconds, but i had this same problem and ignored it and it was a mistake wish i knew what it was.

 

[cliffkemp]

sounds like your thermostat is sticking open. Also, check to be sure you are getting good flow of coolant to the engine with a pressure check. If you are not getting much heat when it says it is cool, the heating system is fine as you should get heat based on how warm the coolant is in the engine and circulating through the heater core.

also could be your sensor acting up. Just make sure your system doesn't have air in it. You don't want to blow the motor up.

 

[KevinMCMXXCIX]

On my car, the temp gauge doesn't go any higher then a little below the middle.
I don't have any problems whatsoever..
Heater gets hot good. Same for the airco
Engine doesn't sound bad or any weird noises either, so no need to worry in my opinion.
As long he doesn't heat up till max, there ain't no problem.
Friend of me has a Civic like me too. But his gauge goes halfway, not hotter.
But no sounds whatsoever. But he needs to fill up his coolant so that might be the reason his temp goes halfway and mine isn't