it takes ~10 minutes to get to the middle of the thermostat...then when i turn on the heater it slowly goes back down...and even when its steady in the middle...the air isnt warm enough.

Maybe you need to replace your thermostat. It may be stuck open.

That's interesting. It only takes about 2-3 minutes for my car to warm up completely. I just drive it in whatever gear keeps the car at around 3000-3200RPM so it'll warm up a little quicker in this weather.

I did notice, however, than when my temp. guage is at it's normal warmed up area that when I get on the highway it'll go down and have to go back up a little. Could that just be because it's getting that cold air thrown at it or something?

I have the exact same problem as 95se-r. I replaced the thermostat 8 months ago, so I don't think that's it; anyone else have an opinion?

When I changed my coolant it warmed up faster.

Originally posted by Rittmeister
I have the exact same problem as 95se-r. I replaced the thermostat 8 months ago, so I don't think that's it; anyone else have an opinion?

I had all those problems also on my NX2k just last week but it's all fixed now. You may want to have a look at your waterpump & your rad cap.

Originally posted by kleensleeper
I had all those problems also on my NX2k just last week but it's all fixed now. You may want to have a look at your waterpump & your rad cap.

Can you explain the waterpump and rad cap statement? I'm guessing the water pump is OK since the car is still alive ;) but can you elaborate? I'd appreciate it a lot.

TIA

http://www.sr20deforum.com/showthread.php?s=&threadid=23904

Well this is all familiar to me. since the temp outside has dropped down to below 50 degrees I have noticed the same thing.
I have a CMX and the temp. settles around 140-160 for some time till it decides to finally climb to Normal Operating Temp.
I have a new water pump, 6 monthes old, t-stat 1 year old, and coolant that is 6 mothes old.
Now I am guessing at this but when the T-stats starts to open it introduces cooler water from the radiator into the engine. Thus decreasing or leveling out the temp change for a few minutes.

Any comments?

Originally posted by kleensleeper
http://www.sr20deforum.com/showthread.php?s=&threadid=23904

OK, now I know about the WP. Can you please explain about the rad cap? If I just need to replace it, fine, let me know, but I'm also curious why. Personal edification and expanding my mind, all of that...

About the rad cap.... The dealer said the rad cap wasn't holding any pressure. After i changed the water pump,the cooling system was still acting up(takes a long time to warm up & would overheat after driving for a short time. If your cooling system worked fine for 2 years like me & you change one major thing like the water pump it seems to mess up the whole system(For my nx anyways). I guest everyones car is different. After all...a rad cap does'nt cost that much.

Have you had your radiator replaced, or a previous owner had it replaced? Do you have an AC condenser? Do you have anything other than stock cooling system parts? If no to all these, change your coolant, more anti-freeze than water. Maybe 50/50, that's more than enough for winter.

probably not your situation, but when I changed the ARV(fast idle), the temp gauge seems to move a lot faster now. Before it would take 5 minutes of idle to get the needle moving, now it starts moving within a minute.. interesting

WOW!!!!!!!! My classic takes a long ass time to get warmed up and then when i drive it , the temp goes down. WTF!!! Is there something wrong w/ the SR20? I just bought a thermostat and im going to replace it this weekend. If that isnt it then what can it be???

It's <25*F over here and my car takes at least 15min to warm up. By warming up I mean 150-160*F. I have the 300zx rad cap and water wetter. It doesn't reach 180-190 unless I've been idling for like 30min straight.

This all started when I put my FMIC in...I wonder why though?

I also think that my thermostat is stuck partially open.

My friends Spec V warms up in like 2min.

wow, you guys definitely have some issues. And about the water pump. A water pump can fail slowly without you noticing. As this happened to me with my maxima. My engine woudl start screaming a high pitch noise and I didnt know why, it was really my water pump slowly failing. My max also wasnt heating up as fast as I liked. ONce the pump was changed it heated up as quick as a new car. Thank god my se-r only takes about 1-3 minutes to heat up in the cold. Good luck.

Put on a new radiator cap this afternoon, it seems to help. More tomorrow...

According to the temp gauge:

I had a car that would take ages to warm up. It would run cool while moving and stay cool while stopped at lights, then spike hot after getting moving again.

Turned out to be the water pump. It was so corroded that there was only one blade left to do the pumping. Therefore there was only ever flow at 3K rpm +.

People. It is no longer summer and some of these cars are over 6 years old. Do the math! Duh!