Hey guys, I figured someone here would know the answer to this. It is a little long winded,so bare with me, but here it goes------ What I wanted to ask you all is - I have a 1989 GTA with a 350 (5.7 TPI) I just purchased the car and I live in Florida. Well today was the first time that I drove the car since I just got it registered. It was about 92 degrees today with high humidity. When the car was driving, the temp stayed around 220 degrees, but when I got to work, and let it Idle in the parking space for a while, it got to about 245 degrees! So what I really wanted to know is, if the fans on my car are working properly. Here is what I noticed - as soon as I start the car (when it is cold) the fan on the passenger side of the car comes on right away (Even if I just turn the key on and not start it) I thought this was strange. But hopefully someone here will know if this is normal or not. then If I drive a while and pull over and the temp is about 220 the fan is not on anymore. But if I let the temp go up to about 245, the fan on the passenger side will come back on, and start to drop the temp a little. If I put on the AC, both fans work, and it seems to run cooler. Does it sound like things are working properly? If so, and I wanted to make things simple, how would it be if I installed a (Hypertech Thermomaster Chip), and left everything else the way it is (Stock) do you think this will help me? (I know the Hypertech chips are supposed to turn the fan(s) on at different (Lower temps). And how do I install this chip, and how much are they? Sorry this is long and I probably lost you all, but I desperately need help! Thanks in advance for any help People! I really appreciate it.
Take care
Mike


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SmokinGTA-Pirate

 

Welcome! I see it's your first post!

Things sound pretty close to normal to me with the exception of the fan coming on when you first turn the switch on. The stock fan turn on points are pretty high like that. Also, that temp gauge isn't exactly a precision instrument, as can be seen with a scan tool. They are typically pretty far off, and I would be more apt to believe the CTS and the computer on the temp.



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Working on:
'84 Z28 LG4 305 with 200,000 original miles!
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350 (ZZ430)
using primarily GMPP parts.
Short block sitting on a stand. (Man, those Fast-Burn heads look good, (just sitting there doing nothing!LOL))

Starting to look like the Kicker poster child!

ASE Certified Master Tech

 

Hey man, thanks for the welcome. Yeah I am not too sure about that fan coming immediatly on as soon as the key is turned. But it is strange that it goes off again later and then comes on around 240-245 degrees. Why would this be? I originally thought that someone rigged the fan to come on all the time, but if that was the case, it would not go off, and then come back later on at 240-245. I just don't like it to run that hot when sitting (Idling). If I put the AC on, both fans come on, and it cools better, about 220 degrees, but I don't always want to run the AC. Also how hard is it to install those Hypertech chips?? Hey it sounds like you have one hot car you are working on! That will be a runner for sure! Thanks again for all your help man!
Take care
Mike

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SmokinGTA-Pirate

 

I don't know why your fan would come on when you first start up, either. Only time that should happen is if your motor is hot from being driven recently and the temp is still up. If it does it from a cold start, then something is wrong, sorry, I don't know what. As far as the hypertech chip thing goes, you don't need to change the chip. Just change the fan switch between the #6 and #8 plugs with a lower temp switch. The stock ones come on about 239*, which is already too hot... That in itself will keep you running alot cooler. They run about $45 or so...

KAM

 

Hey West Coast,

I would also like to say welcome to a fellow Floridian!
The previous owner of my car wired both fans to always come on with the key. if yours isn't wired that way, it seems as if you have a faulty temp sensor. If you don't want to wire them so both are always on,(I'm thinking of undoing mine but it's so hot here, I need all the help I can get!) then a lower temp fan switch is probably the way to go. Have you checked your thermostat? Putting in a 170* or 180* should lower your temp some as well.
Also, JP is right about the factory temp gauge not being very accurate, mine shows a lower temp by about 15* than a scan tool at 180*.

Good luck!

Ken

 

I'll tell ya, this has got to be THE most asked Tech question on third gens.

As noted before, the secondary fan switch, located in the pass side head, turns the fans on at 239. JET sells a replacement switch that turns the fans on at 200 and off at 185. You also have to use a 180 thermostat. I have to tell ya, I had one in my 88 Formula 350 and the gauge was pretty damn acurate. You could watch the gauge then go look at the fans turn on. So, it is one of the best mods you can do. Also, be sure the radiator is in good condition, you have a good cap that is not defective and a good waterpump that is a reverse direction and last but not least, make sure the airdamn is intact.

 

Thanks everyone for the help and the warm welcome! You all gave me some great advice. It is also nice to see another Floridian out there. I will change the fan switch out, and the thermostat to a lower one.(maybe 180 degree) As far as the fan coming on as soon as I start the car, Maybe Ken88GTA is right, it may be a faulty Temp sensor. Does anyone know where that sensor is located on an 89 GTA? I might try and change that out also.
Thanks again all and Ride on!
See ya
Mike


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SmokinGTA-Pirate