: is this normal?

03-24-08, 02:08 PM
i have a 2000 deville dts for the most part the temp gauge stay directly in the middle between cold and hot but like if im stopped at a long light it will go up slightly almost but never past the next 8th dash mark then will slowly go back down to the half mark.....is this normal or is something failing?

03-24-08, 02:32 PM
Sounds normal to me. Do some searching around to gain info on the N* cooling system and maintenance. Start with the Tech Archive top of page then search for info on the site. Lot's been said and lots to be said, good info brings understanding. K_C

03-24-08, 02:37 PM
well i have had the car for over a year now and like i just replaced the water pump t-stat and just noticed it doin this....i think it just stayed in the center before without moving but never really looked until recent problems

03-24-08, 03:58 PM
As the system bleeds off air and gasses, I think you'll see less gauge needle variation, but it is entirely normal at idle or in slow traffic to have the needle move up a bit, a fan comes on slow, and the temp drops. If you have the A/C system in AUTO, then a fan will run all the time and the variation will be practically nothing, but the constantly running A/C compressor will cost you some gas mileage, particularly in and around town. I make it a point to run the A/C only when I need it for cabin cooling or dehumidification, and it makes a significant difference in my gas mileage, winter and summer.

A truly anal owner could rig up 3 LED's from the front fuse/relay box: for Fan 1, Fan 2, and Series, then try to guess which will run when and how.

03-24-08, 04:35 PM
Do The Fans Have Mutli Speeds Indivitually?

03-25-08, 10:12 AM
Each or both fans will run depending on conditions and A/C system use, and there's a second relay in the fuse box which is used to run the fans in parallel (high) or series (low).

If you pull the relays you can figure out the wiring diagram from the graphic on the side/bottom of each relay: they're different and have different pins.

The fans are also fused, 1 and 2.

With A/C on (there are several modes which automatically run A/C/) one fan runs all the time and the engine stays around 212. If the engine temp goes to 224, the second fan will come on. A/C or not, when the engine temp gets to 236 (or the transmission goes over 304 (!)), both fans shift to high. The coolant mix and cap pressure hold boilover to 264 degrees.

03-25-08, 10:57 AM
thanks a lot.... just wondering i have dashes i dont have a guage that displays temp in degrees anyone know how many degrees each dash stands for?

03-25-08, 11:42 AM
Approximate temps........close enough. Thermostat starts at 188, open at 206. Fan at 224, both high at 236. (Thanks to ???? for the pic in here a year or so ago.......not my work)

Click on pic and scroll in.

03-25-08, 11:47 AM
thank you bro..... thanks for all the help

03-26-08, 09:21 AM
When Im Sitting In Traffic Or Stopped My Car Is Staying At About 234 Until I Rev It Or Unless Im Driving Is That A Problem? Both Fans Are On

03-26-08, 09:43 AM
Stuck in traffic, the first tick after 12:00 is OK. It should creep down some as you start moving. If your HVAC system is set to AUTO or some mode in which the compressor runs, at least one fan will run all the time. Even now (March), stuck in traffic under those << conditions, a second fan may well come on, and it sure will in summer, then they'll both shift to High speed, and when they do, you'll know it because you can hear them in the car.

03-26-08, 10:00 AM
Sounds Good It Just Never Acted This Way Before.......how Would I Know If The Waterpump Tensener Is Bad Or The Radiator Is Clogged?

03-26-08, 10:38 AM
Put the drive lug from a 1/4" drive breaker bar in the square hole in the back of the tensioner. Use the bar as a lever to move it and feel the tension.

No reason that the radiator should be clogged, but you could check the temps in various places with an infrared thermometer or maybe with your hand if you can get it down there.