giosoccer20

'00 z28: Today as I was going to school, I got caught in traffic and sat dead still for 15 min. I had the heater on but not blasting, and it was like 48 degrees and raining. I noticed that my radiator fans hadn't come on, and I could swear some steam was floating around the nose of the car. Not sure if it was the exhaust of the car ahead of me, or, - what I"m afraid of - smoke from my car. I didn't notice any coolant smell.

The temp gauge stayed perfectly normal the entire time. Does that mean I'm just being paranoid and there is no problem? Every day but today, i've noticed the fans kicking on at some point in time. Is it just the colder temperature that is stopping the fans from coming fan, even if it was idling for 15 min?

When I got home, I let it idle again for another 5-10 min and again, the fans didnt come on. I saw no smoke from the engine or anything, no coolant in oil, etc etc. Am I just being paranoid? I had a '99 subie 2.5 rs and that thing drove me up the wall with an internal head gasket leak

RPM WS6

iTrader: (3)

Just because you're being paranoid doesn't mean that they AREN'T out to get you!

Do you have a scanner? If so, you can read actual coolant temp rather than the buffered temp shown by the gauge ('99+ water temp gauge shows within a hair of the 210° mark for anything ranging between about 185-190°F to about 230-235°F).

FWIW, unless you're using the A/C, the fans won't kick on until 227°F (low speed), or 235°F (high speed), with stock tuning. So on a cold day, it's very possible that it would take a long time for them to come on at idle.

What indication do you normally use to *know* that the fans are on (you mentioned that they usually come on every day)? Do you catch the momentary dip of the volt meter? Or do you actually hear them from inside the cabin? If you can actually hear them, then it must be the high speed setting that's activating, because it would be nearly impossibile to hear the fans at low speed from inside the car.

High speed should not be needed in cooler outside temps, if the cooling system is functioning properly and fan tuning is stock.

giosoccer20

ooh okay. I usually just hear them after I'm cruising on the highway for my daily commute to work for 15minutes, and then having to wait at a stop light for a 2 minutes or so. And yeah they do sound like the high speed. Again, I haven't noticed any issues with overheating, drop in performance, or anything suspicious in the coolant or oil or anything.

today after school I was listening with the hood open and couldn't hear the fans. This could be for 2 reasons lol... A. loud exhaust, and B. fans never went on their high speed setting since it was cooler. Honestly, I feel like the car would've overheated by now. I've had in the hottest days of summer this year and it never overheated and the fans always kicked on. and today, it was just sitting for 15 min after a drive and it didn't overheat.

I do have a predator tuner and I know I can adjust what temp I want the fans to come on, if that's what you're referring to? I appreciate your help!

demonspeed

iTrader: (7)

The steam you might have seen could have just been from the moist air hitting a warm, steel hood.

edit: These stories from you guys in high school bring back memories from having my Camaro back then... I had an '89 IROC-Z back then ('99-'01) and my buddy and skipped class one afternoon. It was pouring and we also noticed "steam" coming from under the hood... and then through the vents, lol. My fans did not turn on that day and essentially blew the radiator up. Quite the learning experience, but it was the first of many...

giosoccer20

oh god...haha. I'm not in highschool, though. It's my 3rd year in college. I just refer to it as school. I wish I had my camaro back in high school! Instead, I had a lame *** '95 GT 5.0....which in fact was pretty cool...but nothing compared to an Ls1

I feel if coolant steam was coming through the vents, you would've definitely smelled coolant? I haven't gotten the slightest whiff of coolant yet. And I do also think that it could've been the moist air hitting the warm steel hood thing

RPM WS6

iTrader: (3)

Have you ever made any adjustment to the fan settings with your tuner? Or are the settings for fan cut-on/off still stock?

I ask because this part of your post concerns me:

You shouldn't really be hearing the high speed fans that often under those conditions, at least not with stock fan settings. In fact, I can't ever recall hearing the fans hit high speed, with stock tuning, unless my A/C was running on a hot day. Reaching 235°F while idling in traffic for only 2 minutes really should not be happening, assuming that the low speed setting is working as it should.

How many miles on the current water pump? And radiator? Are all the pieces of the air dam still intact? When was the last time the coolant was changed? Is there a lot of debris stuck in the condenser fins, possibily blocking air flow to the radiator? Do the fans ever activate at low speed first, as they should? It would be helpful to have a scanner and see exactly what is happening with coolant temps and if/when the fans engage at either low or high speed.

This all may be normal, if you (or someone else) has changed the fan settings at some point.

giosoccer20

I will look into everything you said with more detail. Maybe I'm just hearing the low speed fans? but you said that they would be really hard to hear from inside. I really do not know for sure if what I'm hearing is the high or low speed, because I don't know the difference. I just remember that I'd always hear the fans come on in the usual circumstances. I'll plug my tuner in and see what the setting are.

The gauge never reads more than halfway, which I believe is 210? And, I mean, the gauge is working right? It's not like it would show the engine warming up and then stop showing any higher temperature?

Also, I had the coolant flushed in August. And I believe I remember the p/o saying he changed the water pump. However, I'm not 100% sure about this

giosoccer20

OKay, I just plugged the tuner in, and here's the news. It has the diablo custom tune installed, and the fan 1 ON temp is 196.something, and the Fan 2 ON is 203.something. I assume Fan 2 would be high speed?

that makes me concerned because if fan 2 comes on at 203...why didn't I hear them today? did the engine really never reach that temp?

fruitsalad

iTrader: (5)

It will show extremely high temperatures like an overheating condition, but not really anything in between that and warming up from dead cold. I have watched my coolant temp on my scan tool while driving and the gauge stays just a hair before the 210 line for everything from 199° all the way up to 220ish, like RPM WS6 said. If your Predator has a scan tool function, open it up while you're driving or sitting in traffic and see what the actual coolant temp is.

RPM WS6

iTrader: (3)

Exactly. Seeing "210" on the gauge doesn't actually mean that the engine is at or below 210°. It could be as high as 230° and still show "210".

Yes, if it's listed as "Fan 1" and Fan 2", then 1 must = low and 2 must = high (because both fans should always work simultaneously at the same speed).

And those are definitely custom settings, since they shouldn't come on until 227°F (low speed) and 235°F (high speed) with a stock tune.

Do you have a stock t-stat? If so, about the coolest temp that should ever be reached is around 190-192°F, post initial warm-up, as per a scanner (stock t-stat is a 187°F unit, and I've never seen one maintain anything lower than 190°F regardless of fan operation, cruising speed or outside temps that are still above freezing).

If it was cool enough outside, and the fans were already running at low speed (on at 196, per your custom tune), then it's possible that 203°F may never have been reached. Were the fans running at all when you had the hood open and were idling for that period of time? You can't hear them very well at low speed, but you'd be able to see them running and feel air flow from behind and in front of them, if they are on. On high speed, you can't miss the sound as well as the air flow. High speed is what you have likely been hearing previously from inside the car.

With those fan settings, if you still have a stock t-stat then it's entirely possibile that the fans have often been reaching high speed, as you've noticed in the past. Perhaps today was cooler, and running the heater would have removed some heat from the system as well.

You really need some kind of comprehensive scanner to see actual coolant temps.

dailydriver

The Predator DEFINITELY has a scan function for ECT, and one can even data-log this info.

IF your system is VERY efficient/clean (inside AND out), with the correct coolant mixture, and a good, strong water pump, there IS a chance that even your low speed fan will not come on in cool enough weather while idling, EVEN WITH those lower temp tune settings for the fans.

LS6427

iTrader: (2)

48*F out, you probably never reached 196 for the fans to go into low speed.

After you were cruising before you stopped in traffic the temps were probably around 160.......COOL......

.

RPM WS6

iTrader: (3)

I don't think he mentioned what t-stat is in the engine though. 160° would be possible under those conditions, if it had a 160 t-stat. But there's no way that it would get that cool on a 48° day if it still had the stock 187° t-stat, or even a 180°.

OP....do you happen to know what t-stat you have?

giosoccer20

No I do not know unfortunately. However, I do have good news. I drove to work and like always, after the 15min drive up 476, the fans were running at that stop light and when I pulled into work. Everything is working like before!

I guess it just wasn't hot enough this morning. I took a quick ride up the highway as the engine was still warming up, and then sat in traffic. So I guess it wasn't enough to trip the high setting

giosoccer20

Thank you everyone for the input. I think I just had a case of early morning paranoia haha

giosoccer20

You're probably right since it was just a 3 mile drive up the highway and the motor was still heating up. I was just really surprised that after 15 min of sitting in traffic, I never HEARD the fans on their high setting

giosoccer20

and to end this on a good note. I plugged in my diablo tuner, and did a scan. everything is fine!