Car overheating, fan dosen't turn on in time

[MTCFORUM]

About 6000 miles on my new motor and I am noticing that my car wants to heat up some days while sitting at idle. I've noticed it at a few drive throughs.

It's intermittant, but when it does start to heat up I notice that the fan dosen't kick on until after it passes the the text on the guage. I can turn on the A/C and it will fire the fan up, and cool the car down.

Am I looking at that fan controller, or is there a sticky temp sensor somewhere else that may have an effect on this.

It's a 94SC auto.
Brian

[MTCFORUM]

Brian,

I had a similar problem last summer. I had to kick on the defrost and set the temp to 90 degrees to get it to drop below M. Only problem is you're now heating up the condensor coils... and you can't run the heat in the summer with a baby in the car. <IMG NAME="icon" SRC="http://images.zeroforum.com/smile/emsad.gif" BORDER="0">

The stock settings for the fan is 212 degrees I think, with a 195 degree t-stat. I plan to correct it with a cool fan switch and a 180 degree t-stat. I'm going to be using XR7 Dave's FAQ on the TBSCEC to wire up the relay, and probably add a manual override for the low speed setting. I'm also going to replace the temp sensor for prosperity sake. It's 8 yrs old in my car.

Other than that, you may want to run a colder plug with a shorter tip and smaller gap. Later, and thanks for the link!

Paul

Paul

[MTCFORUM]

oR just stick a chip in that thing like i've been tellin ya with a 160 stat.

Chris

p.s. you still have the stock 94 plastic radiator in that thing?

[MTCFORUM]

I don't like my 160 thermostat, I'm going back to 180. I find that the car won't heat up lots of times. Also Fred tells me that there is a cold start strategy that is in effect until "somewhere" after 170 which means that your mixtures could be a little wack. I find that mine will sit at 150 sometimes and I think that it doesn't run as well at that temp.

If you are having occasional temperature fluctuations, I would be suspicious of possible air pocket. Air pockets will cause that. Otherwise, don't be lazy, set up a proper fan controller. <IMG NAME="icon" SRC="http://images.zeroforum.com/smile/emsmile.gif" BORDER="0">

[MTCFORUM]

I think I actually have a problem or failure. My fan dosen't even kick on sometimes until the guage hit's 3/4 or 1/8 past the M in NORM. It then shuts off still to the right of the word NORM.

I think the car runs really well when the guage is right in the middle. I don't trust the guage though, so hopefully I'll replace it with one and maybe a pilar dual guage pod. I don't want to destroy a motor by overheating it.

Brian

[MTCFORUM]

Brian,

We started a nice discussion on the 94-95 setup on the TBSCEC. So far I've discovered are cars suck... j/k <IMG NAME="icon" SRC="http://images.zeroforum.com/smile/emwink.gif" BORDER="0"> Apparently our fans kick on at 222 and 228. I've also been led to believe that the main (puller) fan does not even use it's high-speed potential. That's left to the aux. (pusher) fan in front of the condenser with the help of the main fan.

Since I'm cheap (read: broke w/ kid) and can't afford a tuner, I'm going to figure all the wiring out and re-wire the aux. fan to work with the A/C switch, and use the main fan for the radiator. Going to set it up for about 194 and 205 respectively with a 180 t-stat. I may be wrong, but according to Chris (toid), both fans are wired for two-speed operation. Hopefully that's true and I'll have something new for us.

(edit) If the fan kicks on with the A/C, then the CCRM is working. If not, you know what's causing the fans to not kick on. If the fan does kick on, you'll need to check the coolant temp sensor and wiring to see if that's a problem. That's just a starting point though.(/edit)

Paul

PS: Dave, mind if I email you for suggestions and advice?


[Modified by pablo94sc, 2:00 AM 3/5/2002]<BR><BR>
[Modified by pablo94sc, 2:01 AM 3/5/2002]

[MTCFORUM]

its the same motor as the early model sc's.. with the exception the shaft is a tad bit shorter and the plug is different. Although like you said the high speed is not used. I believe that pusher fan is spose to come on with your A/C. I could be wrong on that. The only time I've ever seen mine on is when my main fan died.

ChRiS

[MTCFORUM]

I would personally wire (if it is not already) the pusher to come on with the A/C. I would wire the low speed fan to come on no higher than 190 (with a 180 thermostat) and the high speed 190-195. There is no need for the motor to get that hot. I would use adjustable thermostat switches and tap in on the low current side of the IRCM. That is how I have done all of my cars. It's cheap and real effective.

[MTCFORUM]

Chris: I've never seen my aux fan kick on, only heard it once when the car got really hot last summer. My main fan in always used with the A/C, car but it may be different in your car. And yeah, I don't think the high speed portion is used at all on either. What a waste. See you in STL.

Dave: Can you send me a wiring diagram for your switch. I'm going to need that as a starting point when I start making mine. If i'm going to re-wire this bugger, I'll need all the help I can get. Too bad I'm not in Cincy yet or I'd drive up and let you look at it. <IMG NAME="icon" SRC="http://images.zeroforum.com/smile/emsmile.gif" BORDER="0">

Paul

[MTCFORUM]

Check the FAQ's on TBSCEC, you'll need to go to page 2 I think. <IMG NAME="icon" SRC="http://images.zeroforum.com/smile/emsmile.gif" BORDER="0">

[MTCFORUM]

Hehe... everytime I looked at it before all I got was the big red X. Looks like it loaded this time. <IMG NAME="icon" SRC="http://images.zeroforum.com/smile/emsmile.gif" BORDER="0">

Paul

[MTCFORUM]

Check your low speed fan relay. If the fan does not turn on until past the text on the gauge, that's probably the high speed relay turning on, which is a back up to the low speed relay just in case the low speed setting can't cool the engine. Just because the fan comes on with the a/c does not mean it's operating properly. The a/c activation is through a different circuit which I believe turns on high speed anyway. Check on that low speed relay and get back with me.

[MTCFORUM]

Ohh forgot to report the fix <IMG NAME="icon" SRC="http://images.zeroforum.com/smile/emsmile.gif" BORDER="0">

After the Dyno tune and my custom Jerry chip, the problem has gone away!

Thanks for all the input!
Brian

[MTCFORUM]

Well that's the best fix of all. <IMG NAME="icon" SRC="http://images.zeroforum.com/smile/emsmile.gif" BORDER="0"> Right now I've got the main fan with a fan switch like Dave's. I haven't gotten past R yet with the A/C on in stop and go, so I've set the aux and main fan's high speed setting on the back burner. I'll let everyone know what I find out though when I get back to it.

Paul

[MTCFORUM]

hi yall, well i just became a memeber, so whats up to all. I came across this post and ive been hammering this same problem for a while now, fan wont turn on until my temp reaches the R, then the fan kicks in and my temp will go back down. Now on the fan having 2 gears, what ive noticied is that my fan will only work on 2nd gear when the temp reaches the R, is the fan supposed to come on sooner in 1st gear?????? Now if i turn my a/c on my fan turns on, and my car stays cold. But i havent seen my first fan gear turn on. Only the 2nd when my car reaches the R. Im guessing IRCM??????? BTW i have a 95 3.8 non s/c.

thanks for the help
CamellionCat

[MTCFORUM]

cat,
On all the tbird I have owned, that seems normal for the V6s in warm weather. Best bet is to give dennis a yell to get a chip. It's worth the cost.

Brian

[MTCFORUM]

yeah thats what im planning on doing, its one of my future mods. Thanks for the reply Brian.

CamellionCat