: Any way to get the Catera cooling fans to come on earlier?

11-20-07, 02:55 AM
I'm need to get my temperatures down.

None of my fans will come on until my temperature gauge gets all the way to the large tick mark right by the red-line. (about 3/4 of the way up) Then all 3 fans will come on, run for @ a minute until my temp is only 5/8 of the way up the gauge, then all 3 kick back off. The temperature never goes below the 1/2 line.

I need my fans to come on earlier to keep my coolant temps down. I found today that Cateras use the radiator end tank to cool the trans fluid. My transmission slips only when my car warms up @ 5/8 on the gauge, and these excessive coolant temperatures may offer some explanation why the slipping started.

Is there a temp sensor before all the fan relays in the circuit that I can replace with an adjustable after market one?

11-20-07, 03:55 PM
change your thermostate

11-20-07, 04:54 PM
a 160 or so woulod be nice

11-20-07, 05:22 PM
one for a geo metro would be nice in the summer lol..... well i bet your heat works REAL WELL.

11-21-07, 03:44 AM
Thanks for the responses everybody. :D
The coldest thermostat I've been able to find has been a 180 degree stat and the cheapest I've been able to find it is $42 from 'the zone', mostly because it includes the thermostat and stat housing as all one piece so it only fits 97-01 Cateras and Some Saturn LS's. It's totally different than the standard thermostats that come in every temperature available and interchange in almost every car.

Has anybody here changed the thermostat on their own? I've never seen one so buried before. It almost looks like it's somewhere under the driver's side cylinder head, and the intake plenum and most of the top half of the engine needs to come off. Is it as difficult and time consuming as it looks, or is there an easier way to go about this?

Side note...yeah my heat does indeed work better now than it has since I bought it in 02, partly because of it running very warm, but also because I had the standard heater problem where freezing cold air always blew out the psgr vents, but my A/C stopped working a few months ago so now it can't blow ice cold air anymore.:thumbsup:

11-21-07, 07:43 AM
LOL sounds like your car is having some issues. as far as the 42.00 thermostat thast high. i might go have a look at one and compair and let you know..

11-21-07, 09:48 AM
The real way to get the fans to come on earlier is to mess with the coolant fan temperature switches and the activation points. I wonder if theres some bigger problem causing you to have elevated engine temperatures.

Here is a schematic of the cooling temp sensors etc. and a guide about what temps the fans are supposed to come on at (Click to make larger):
http://img89.imageshack.us/img89/3928/schemtr6.th.png (http://img89.imageshack.us/my.php?image=schemtr6.png) http://img137.imageshack.us/img137/7426/schem2ah8.th.png (http://img137.imageshack.us/my.php?image=schem2ah8.png)

11-21-07, 10:58 AM
2 issues here:

1) if NONE of your cooling fans are coming on until you reach that top temp, problems with the fan control thermostat(s). Vesicant's post covers it with the diagrams.

2) If the fans are cycling per the diagrams above, you have a aux pump or radiator issue (or something that prevents it from cooling good). My Cat, when I bought it, acted the same way as yours, and working great even in +100 temps this last summer after the work I did to it.. I have another post covering all that I did to mine.

Before I did all the work I used a temporary fix - a jumper on the coolant test connector to make all fans cycle when the second stage comes on and keep them ON until the first stage turns off.
Not a FIX, but will help if you have to drive it. And will only help if the fans are working properly.

11-22-07, 02:21 AM
Thank you everybody :bouncy:
The info and schematics in these posts are exactly what I was looking for.

Those fan switches are in a somewhat stubborn spot, but once I move a few things out of the way, I should be able to replace them pretty easily with either lower temp direct fit pieces or aftermarket adjustables.