Radiator Fans not starting properly

dragonwebz · 06-26-2010, 01:48 AM

I did a quick search for radiator fans throughout the site and couldn't find anything related to my problem. I just recently had to replace the lower intake manifold gaskets due to a leak about a month ago. Car has been running ok, i guess, considering most other member's aleros run in the 180 to 210 temp range, which is where mine runs at. However, my radiator fans aren't turning on at all that I've noticed this past month other than one time. I know I hooked everything back together after replacing the gaskets and am wondering if anybody knows what else could be the problem. It was running so hot at one point earlier today that I think it blew the o-ring on the coolant tank cap. If the fans were working, that should of never happened.

[ion] C2 · 06-26-2010, 01:57 AM

You do realize that the fans don't turn on until 223 F, and that they also do not flow anywhere near enough air to cool down an overheating engine?

Your problem lies elsewhere.

Also, welcome back, you've been gone since '06. Only show up when you have a problem?

dragonwebz · 06-26-2010, 02:13 AM

ha ha... thanks for the welcome back! College, home improvements and work left me with no time. Plus I've been really lucky so far with my car. (Knock on wood). I had my dad help me with gasket replacement and I think he must be used to working on classic cars or something because he says that a car thats running "that hot" and the fans to not work isn't "normal". I'm still new when it comes to engines and rely on my dad and forums to teach myself. Anyway... no I wasn't aware that the fans don't come on until 223F. I'm confused then, if I have a 195F thermostat but the fans don't come on till 223F, whats the point of the thermostat??

Lucalare · 06-26-2010, 02:31 AM

195* thermostat means that coolant doesn't flow until 195*, that is by no means the hottest the engine will get. An overheating engine would probably be about 280* or hotter, depending on the engine

dragonwebz · 06-26-2010, 02:09 PM

From what I've been reading, the fans don't really help that much at 223* and higher. Why don't they come on any sooner? Wouldn't it make sense for the fans to come around the same time the coolant begins to flow? That way the engine wouldn't be too hot for the fans to handle, therefore increasing their efficiency. Although I am a beginner at this so please bear with any of my potential stupidity. lol!

Lucalare · 06-26-2010, 09:26 PM

Don't worry, we all started off knowing nothing. The reason they don't come on before that temperature is that there is an ideal temperature for an engine to run at, not just as cool as possible. I'm guessing that for the LA1 that temperature is 223*

[ion] C2 · 06-26-2010, 10:22 PM

No, that temperature is 200-210ish.

Who knows why GM set their fans to come on late, or at all, really. I've set mine to stay on all the time, and the car will still run at the same temperature it was running before. When I was on the dyno, the giant turbo fans did nothing for temperatures. Liquid cooling > air cooling.

dragonwebz · 06-26-2010, 11:11 PM

How do you get yours to stay on all the time. Is it just a matter of re-wiring it to a switch on the dashboard?

BlackJack · 06-27-2010, 10:15 PM

well, you CAN wire them to stay on all the time or get a Caspers fan switch, but in cases like C2 and me, we have PCM programming capability, and we can set it in the computer what temp we want the fans on/off at, and how long (or if) they stay on after the key is off.

dragonwebz · 07-04-2010, 12:18 AM

I figured I would post an update with the hopes that this update might give me an answer to what is really wrong with my cooling system. The fans do come on at around 225F, according to my OBD II scanner, however I keep losing coolant out of the overflow tube. I'll fill the car to the cold line and by the time I get to work (7 min.), it's down towards the bottom of the coolant expansion tank. I've dumped, so far, about a two gallons of anti freeze and about a gallon and a half of water in the tank over the last four days, doing minimal driving to just work. (And have had a few puddles on my garage floor). I've heard that I might have too much air in the system from when I did the intake manifold gasket job, however I bleed out as much air as I can every time I start it before I drive to work. I just don't know what to do and can't keep spending money on anti freeze every other day.

BlackJack · 07-04-2010, 01:29 AM

try replacing your reservoir cap (which controls the overflow)?

dragonwebz · 07-04-2010, 02:28 AM

did that prior to the events of the last post. The o-ring went bad in it and figured I'd just buy a new cap.

Monza · 07-04-2010, 02:21 PM

Have you let the car warm up in the driveway and watched the overflow tank?

widbyj · 07-04-2010, 03:50 PM

Watch for bubbles, sounds like HG to me...

Redog · 07-04-2010, 03:53 PM

At risk of sounding like Nate, it's possiblly a head gasket.

I have the same problem right now. Turns out after compression test and compression test and compression test, I'm not losing coolant though any fault of LIMG or pin hole in a hose, but I have a cracked head gasket in such a way that it's allowing combustion gases into the coolant system and the 15 PSI that the coolant system runs on is nothing compared to the 9.5 compression ratio that the cyl are making.

If you want your fans on all the time, always use your A/C.

Also as a side note, once your car reaches 280*, you've already cooked the engine

dragonwebz · 07-04-2010, 04:39 PM

hmm... thanks for the side note. I've bled the system, shut the car off, waiting till its cool enough to open the coolant cap, and then put either more anti freeze or water in the tank. Then I repeat the process. Did that for about 3 hours and am still visually "leaking" coolant out the overflow tube. How do I know if its a head gasket problem? Is there a reading on an OBD II scanner that can tell me this?

BlackJack · 07-04-2010, 05:13 PM

you're going to leak coolant out of the overflow as the car overheats regardless. Or is it doing it while the car is still at a reasonable temperature?

dragonwebz · 07-04-2010, 09:38 PM

I'm not quite sure. I'll have to try and drive it tomorrow to see when the coolant dumps. All I know is that I'll fill it to the cold line and by the time I get to work (7 min) it's at the hot line. I have to fill up every other day if I drive it those days.

Redog · 07-04-2010, 10:08 PM

Start the car, then rev the motor by opening and closing the TB.

If the coolant goes out of the tank when at WOT and then comes back at idle, it's a head gasket, assuming that the oil is clean.

The compression test is done by hooking up the compression thing and starting the car and watch if the gauge drops.

If you did the LIMG gasket yourself, you'll have no prob doing the HG. It's just 8 more bolts, but you CANNOT reuse the used bolts

Monza · 07-04-2010, 11:58 PM

Watch the overflow tank. If it overheats and then pukes it could be the thermostat. Will they fit in backwards?