98 z34 monte cooling fans always on

[Drummer]

Ok I've had cars that have had crappy heat but this is driving me nuts. it's 17 degrees out not including windchill and my temp gauge is not even a quarter of the way up, it's barely even on the gauge, and my cooling fans are on. The only way i can get any good heat is if i step on it going up a hill, but as soon as I let off the gauge drops back down to where it was before, and i get luke warm air. Almost seems like I don't have a thermostat, but I don't know. Any ideas or questions or anything would be great.

[Night Fury]

My 98 z34 has shitty heat too... I've replaced the thermostat twice, it gets better for a day or two then sits on the gauge right where he is describing. So essentially no heat!!

[Drummer]

are your cooling fans on also?

[Night Fury]

No.

[Crazy K]

if your guage works, it is not likely to be the sensor, since it has a 3 wire sensor. if the car runs fine otherwise, the sensor is ok... since the car would run like dirt with a wrong fuel mixture if the sensor gave out the wrong readings.

 

Pull the fan relays, see if that stops the fans.... maybe you might find someone jumpered them...

 

 

and stick some cardboard in front of your radiators if you are having problems with heat.

 

 

 

 

[Night Fury]

if your guage works, it is not likely to be the sensor, since it has a 3 wire sensor. if the car runs fine otherwise, the sensor is ok... since the car would run like dirt with a wrong fuel mixture if the sensor gave out the wrong readings.

 

Pull the fan relays, see if that stops the fans.... maybe you might find someone jumpered them...

 

 

and stick some cardboard in front of your radiators if you are having problems with heat.

 

 

 

 

 

I was thinking about the cardboard, but shouldn't it heat up without it? Is that really an acceptable solution?

[Crazy K]

acceptable? I notice truckers stick those vinyl covers over their grills, so what's the difference?

 

 

I've blocked 80% of the radiator in winter and the car still runs at perfect temp.

[3pt1lumina]

I'm not driving the Monte but the temp gauge hardly moves up at all even when it's warm out I am going to try a thermostat in the spring. My fans are not on, though...that sounds like a different problem such as a bad relay or something.

 

My 96 and white 97 Lumina I have never had heat problems with in the winter... the green one I could never get heat out of it no matter what I did I just got lukewarm heat at best.

[RobertISaar]

considering that there is very little to no coolant flowing through the radiator when it's cold, cardboard in front of it shouldn't do much...

[Drummer]

The thing is that the fans don't turn on automatically. When I first turn the car on the fans aren't on, after it warms up the fans turn on, and it's not just one fan either it's both. I just also noticed that the gauge fluctuates a little bit.

 

[98montels]

acceptable? I notice truckers stick those vinyl covers over their grills, so what's the difference?

 

 

I've blocked 80% of the radiator in winter and the car still runs at perfect temp.

 

Last year and this year I blocked the entire radiator on my 98 3100. temp does not change much at all. when it warms up outside to like 40 I notice the guage goes up to about maybe halfway then I remember the cardboard is in there.

 

Thats right i said the whole radiator

[98montels]

Oh yeah to OP is your coolant full? sounds like maybe your motor is hot thats why the fans are on, and your collant is low so you dont get good heat or at all. maybe you have air pockets. Usually the low coolant light would come on but you never know maybe the bulb is burnt out or somehow its not working.

[jman093]

Oh yeah to OP is your coolant full? sounds like maybe your motor is hot thats why the fans are on, and your collant is low so you dont get good heat or at all. maybe you have air pockets. Usually the low coolant light would come on but you never know maybe the bulb is burnt out or somehow its not working.

 

x2. sounds like the coolant is low or system needs bled. That's why it heats better for a bit when you give it throttle.

[Drummer]

seems possible but ive ran the car like this for 2 or 3 months like this and its never overheated or even made it to half way on the gauge and ive let the car idle for 15 min and it never overheated.

[Drummer]

Ok I think one of my relays might be bad because when I started my car after sitting for 6 hrs the fans turned on after 3 or 4 seconds. Hopefully that solves it.

[Crazy K]

Pull the fan relays, see if that stops the fans.... maybe you might find someone jumpered them...

[Drummer]

ok there's 3 fan relays 1&2 on the passengers side and fan 3 on the drivers side. Drivers side 3 turned off the drivers fan. Passenger side fan 2 turned off the passenger side fan fan 1 did nothing.

[DaveFromColorado]

this is just a total shot in the dark here ... BUT ...

 

if the thermostatic control (for the interior HVAC) is reading an A/C input signal, (like when you turn on the defroster ... because it runs the A/C to dry the air passing over the windshield) that might be kicking on the fans.

 

just a thought.

 

--Dave.

[Drummer]

It could possibly be that, but I still have to put different relays on. It doesn't do it all the time so it could be that, just havent done anything since it warmed up to the 30s and 40s.