AggieIROC13

Howdy! Since I bought my car a month ago, I have noticed that it has consistently been running around 240 degrees (or so my gauge says). That is right below red. I found out that my secondary fan does not turn on, even when A/C is turned on (I knew my A/C didnt work but because there was a leak, so I never tryed it.) My car now as it is warming up here in texas is starting to drift up into the red occasionally, especially coming into town from a highway, stop go ect. Could the fan be the only problem? If so (and anyways), does anybody know any tricks to try and Isolate the problem with the fan, I.e. need a new fan, or relay, or whatever, do I have to just replace everything one by one and try it? Is there a way to find out if the fan/motor is good before trying relay? Also, I was wondering if there could be any other culprits around that I could try out, I know radiator cap might be a problem, so I can try that... but what else could it be? is the secondary fan that crutial?

camaronewbie

Your car will have a fan switch in the pass side head, between #6 and #8 cylinder. It has a single wire to it, and a funny mushroom-looking connector on it. DO NOT get this confused with the knock sensor, located same area, but in the BLOCK rather than in the head.

Stock factory fan switch is set at 238F. You can replace with a lower setting switch if you like, so the fan comes on at a lower temp.

Now the issue ... might be that fan switch is not working, wire missing, broken, etc. Might also be just a bad fan relay for that fan.

If the A/C needs charged, there might not be enough pressure in the system to activate the fan (since a pressure switch is used to activate that secondary fan) - thus it might not come one with the A/C if there's low pressure.

But the fan switch and relay will make the fan run when it gets hot enough, regardless of the A/C (assuming the switch and relay are working right). So look into that fan switch and/or relay, and the connectors for them.

Now - one other thing ... please understand that these gauges are far from accurate. They are really nothing more than "pretties" installed by GM to look nice and increase a sales price on the cars with gauges. So - we always tell everyone, if the car is not actually boiling over, it's not overheating (just to ease your mind some about what the gauge reads).

Good luck!

AggieIROC13

No it is definitely boiling over, one thing is that I looked for my air dam and I couldn't find it, I don't think it has one. Is it supposed to be connected right under the radiator?

danielsan

An air dam would be under your nose for the most part. In 80's F-bodies, they usually comprised of cheap material and were commonly ripped off. On a Firebird it's a real problem, due to a lack of a front grille. It's purpose is to sweep up cold air from the ground... but mostly highway speed. I'm ordering one now in fact, as mine is missing.

I actually just got done chasing cooling issues in my T/A. I've owned the car 2 months now, and when I got it I had boiling in my overflow tank at highway speeds or after a LOT of driving. All I did to fix the problem was install a 170 degree Thermostat and "fix" (use this loosely) my coolant fan relay.. which is attached to a coolant probe in the radiator, connected to a "relay ****" - which primarily works as an off/on switch from what I've found. Someone had turned it to a "low" setting.. which almost never comes on. I haven't yet discovered what temperature it turns on at, but at a "high" twist of the **** it seems to work well. You could probably do something similar and connect your coolant fans to an earlier opening temperature sensor.

My problem ended up being a shitty radiator, which I'm replacing shortly. I'm actually ordering an air dam, new radiator and hoses to overhaul my coolant system completely. There's no harm done in ordering an air dam - in fact these 3rd gens seem to be very reliant on them. Without fans opening at an earlier temperature and an air dam, you're going to have heat build up. Even with my electric fans and a lack of an airdam, I see higher temps on the highway because of the loss of vacuum.

If you're having boiling - you're overheating or close to it. Now:

If it's the original engine, you'd ideally want it operating at a lower temperature than the factory setting. A lot of 80's blocks operated at high temperatures for emissions, but it didn't help the health of the blocks. That issue is discussed a few times on these forums and on the main site. 210+ is great for combustion, but awful for the lifespan of these blocks. I personally use a 170 degree tstat (as recommended here=] ) from AC Delco and so far regardless of my (plugged) leak, it has been working flawlessly. That's with my electric fans running off a temp probe in the radiator, and no air dam. I haven't reached near 210F according to my gauges, and when I've checked with a temp gun it's been nothing but good temps. When I first got her, she was running very hot.. 220+ sometimes, with boiling in my coolant overflow afterwards.

Hope my experience helps you

ASE doc

[quote=danielsan;4913169] All I did to fix the problem was install a 170 degree Thermostat and "fix" (use this loosely) my coolant fan relay.. which is attached to a coolant probe in the radiator, connected to a "relay ****" - which primarily works as an off/on switch from what I've found. Someone had turned it to a "low" setting.. which almost never comes on. I haven't yet discovered what temperature it turns on at, but at a "high" twist of the **** it seems to work well.

Sounds like you're talking about a Flexilite fan controller. It's an adjustable aftermarket fan controller that allows you to lower fan on temp with the turn of a ****.

danielsan

Haha, I looked it up and that's exactly what I have. Thanks man!

henryd3

iTrader: (128)

You definitely need the air dam. If you find the fan switch in the location mentioned by Newbie, with the key on, remove and ground that wire somewhere. If the fan comes on the relay and fan are good and you probably need a fan switch. Let us know how that works out.
Check out post#3 on here for a picture of what the air dam looks like
https://www.thirdgen.org/forums/cool...-location.html