So my temp needle has been dead since I bought my Prelude last week. I bought a new temp sending unit today and installed it. The needle now works, but it reads pretty low most of the time.

At high RPM's the needle will move to the middle (normal operating temperature). But when I'm cruising around town at low RPM's, the needle drops to the cold mark.

Ever since I've had the car I noticed that the air doesn't get very hot. Barely even warm sometimes. I live in Michigan and it's frickin' cold out right now and I need good heat.

I'm thinking that the thermostat is stuck open or there is no thermostat whatsoever. :confused What do you guys think?

Also, I'm going to drain the antifreeze on Wednesday and put new fluid in. And put a honda thermostat in. What type on antifreeze does a 97 Prelude take? Is it the regular green stuff, or is that new "blue" honda fluid better?

Thanks

 

How exactly do you flush the heater core?

 

Thanks Chase. So with the water hose running full blast into the thermostat housing, start the car, turn the heat on high and just let it flow out of the lower hose? How long should I let it run for? Probably till it comes out clear huh? I appreciate it man. thanks

 

Ohhh....So in the other post, you're just saying I just need to have the temperature slide/lever all the way to the red(hot) side. But the car is not running so the blower doesnt actually have to be on and blowing the hot air? Just run the water through till it comes out clear? Sorry to be such a pain in the A$$.

 

thermo is stuck open for sure

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMSloLude &raquo;</TD></TR><TR><TD CLASS="quote">thermo is stuck open for sure</TD></TR></TABLE>

Agreed

 

just fyi the needle is about 1-2mm below the center at normal op temp, not in the center of the gague.

 

Yeah. My needle has never been at the middle of the guage. It's usually just fluctuates from cold to almost the middle. The strange thing is....today on the way home from work the needle pretty much stayed where it was supposed to, but the air was still just warm, not hot. I hope when I put the honda thermostat in and flush the system tomorrow it will be hot.

 

OK...I took a look at the thermostat today and it was stuck open. So that solves the wierd temperature problem.

I just put a brand new Honda thermostat in and now that thermostat WILL NOT OPEN! I took the car for a highway run at a constant 5000 rpm's. The temperature guage raises about 3/4's of the way but never actually overheats. I get off the expressway and check the hose coming from the thermostat housing. IT'S ICE COLD!!

With the thermostat stuck closed why isnt the engine overheating?? I guess I'm gonna have Honda order me another thermostat cause this one obviously isn't working.

Anybody have any thoughts??

 

Ok, you need to understand how this all works. To heat the car up the thermo is closed...so it runs on a closed loop, hence the fluid heats faster...then when whatever temp the thermo is set to is reached it opens. It is possible you got the wrong thermo. I had this problem last year and it was a riot. Instead of fixing it I went IRON man for months with no heat. Best thing to do is rip the thermo you had in there out and take it to honda. They will break out the parts they have and it will be clear which one works. Your car not over heating is a good thing. Its not supposed to. Keep in mind when the ice *** cold air hits your radiator is chills that fluid. There has to be someone that can explain with with science but thats the gist.

Good luck...oh and you can test the thermo in a pot of boiling water...sort of like a 8th grade science experiment.

Ryan

 

Yeah. The spring is facing the engine and the peak is facing the hose. I'm gonna take a trip to Honda on my lunchbreak today and see if they can give me a new thermo. I did flush the entire system and put some of Honda's new blue antifreeze in. That right there fixed the heat problem inside the car. Man, I could fry an egg inside my car and have breakfast on the way to work if I wanted to

Another related question for ya.....I haven't noticed my cooling fans kick on at all yet. What's up with that? They should come on when the engine reaches normal operating temp right? Obviously I'm way over that point. Will just the pass side come on, or do both come on?