So I’m out of town, and noticed today at highway speeds the fan seems to be running full speed, it also seems to be revving up super high even when I’m just maintaining steady RPM.

I’ve not had any overheating out of it, but I have been driving in 90-95 degree temps and one of the a/c condenser fans aren’t working. I did see the temp gauge go up when staying in stop and go traffic last week. But since then I’ve been making sure to turn the a/c off when in a heavy traffic or stop n go situation.

Considering it is a plastic fan, I’m just hoping it doesn’t go so fast that it flys into my radiator. At this point, I’m pretty familiar with the fan/water pump assembly, but wondering if someone can guide me to check a sensor?

oooh, lot of disjointed info in your post.

On the FGY33, unless converted, the water pump and main radiator fan are engine/belt driven. they should always be spinning when engine is, and will track engine RPM (this fan is clutch driven, so won't be an exact match to engine rpm).
electric fan should come on with a/c, provided that the a/c system pressures are correct.
your dashboard temp gauge should never 'go up' unless something is not working properly in the cooling system.

3Q Jay wrote: ↑

Tue Jul 02, 2019 2:16 pm

oooh, lot of disjointed info in your post.

On the FGY33, unless converted, the water pump and main radiator fan are engine/belt driven. they should always be spinning when engine is, and will track engine RPM (this fan is clutch driven, so won't be an exact match to engine rpm).
electric fan should come on with a/c, provided that the a/c system pressures are correct.
your dashboard temp gauge should never 'go up' unless something is not working properly in the cooling system.

Hi thanks for input.

The “mechanical” fan is the one I’m referring to. The one which the alternator belt is connected to. The 2 cooling fans in front of the condenser I’m not concerned about, even though one is not working..it doesn’t cause temp gauge to move unless sitting in long traffic with a/c on (I have a 97 maxima and that was a common issue: 1 radiator fan going bad and the engine running hot during idle)

Basically what’s happening is the mechanic fan is running at full speed at all times: when I 1st start the car in the morning, it’s coming on full blast. On the highway, it’s a noticeable “whirr” noise that “races” that wasn’t there until couple days ago. No change in RPM, no overheating...just the sound of the main fan going cucko.

I read before the fan clutch is supposed to disengage once it hits a certain RPM/speed, due to ram air being sufficient to cool the radiator. I don’t think it’s doing that. It’s just running at all times, and sucking energy and coolant along with it.

It basically sounds like I’m driving a uhaul truck at all times. Before, it would only make that sound during high speeds when I was sitting in traffic awhile and under load.

It's cool that you're attentive to your car and the changes it exhibits.

From a general point of view, these 2 scenarios are possible to me:
1. The car is just fine, and the fan is constantly running because the car is being operated in a hot environment - the cooling system is compensating.
2. The clutch is bad, especially if you see the fan running very fast when you just started your car and you know the engine is cold.

"... sucking energy and coolant along with it."
Are you also losing coolant?

on cold start the mechanical fan will be noisy for a few seconds (engine at 1200 rpm or so), but should noticeably slow down within a few seconds, even before engine RPM tracks down coming off of fast idle. Besides the change in noise, you should be able to feel the air volume significantly decrease between right after cold start and 10 seconds later. if not, i'd wager that you have a bad fan clutch (near locked up).

EdBwoy wrote: ↑

Wed Jul 03, 2019 5:17 am

It's cool that you're attentive to your car and the changes it exhibits.

From a general point of view, these 2 scenarios are possible to me:
1. The car is just fine, and the fan is constantly running because the car is being operated in a hot environment - the cooling system is compensating.
2. The clutch is bad, especially if you see the fan running very fast when you just started your car and you know the engine is cold.

"... sucking energy and coolant along with it."
Are you also losing coolant?

Well...I can’t exactly tell if I “lost” coolant. At one point the coolant reservoir was way above full...expansion, but not returning to normal level. I then relieved some pressure from the caps, but it stayed well above full. I then noticed after a couple hundred miles that the level had dropped below full. So could have just been going back to normal level. I occasionally lose half the reservoir of coolant every once in awhile. But KSeal seems to have fixed it.

But I know having the fan running high going 70 mph does feel to take a lot of energy.

3Q Jay wrote: ↑

Wed Jul 03, 2019 5:26 am

on cold start the mechanical fan will be noisy for a few seconds (engine at 1200 rpm or so), but should noticeably slow down within a few seconds, even before engine RPM tracks down coming off of fast idle. Besides the change in noise, you should be able to feel the air volume significantly decrease between right after cold start and 10 seconds later. if not, i'd wager that you have a bad fan clutch (near locked up).

Yeah, that’s the thing. It’s running high as if I just started it up in the morning. The RPMs go down, but the fan stays blasting.

If it’s the clutch, and not any fan speed sensor...that may be reason why I was hearing a slight scraping sound all of a sudden lately on startup. Any suggestions on a temporary grease fix, or is the workings of the clutch internal?

The only "sensor" for the mechanical fan is the bi-metallic spring which sets the tension on the clutch depending on it's sensed temp.
After reading more of your posts, I'm concerned that you have a different problem in the cooling system that just replacing the mech fan clutch isn't going to solve.
having the water pump fan running 'hot' will pull in more air than intended.....which should 'help' your other overheat symptoms. Kseal? sounds like something that clogs the radiator passages......

3Q Jay wrote: ↑

Wed Jul 03, 2019 11:04 am

The only "sensor" for the mechanical fan is the bi-metallic spring which sets the tension on the clutch depending on it's sensed temp.
After reading more of your posts, I'm concerned that you have a different problem in the cooling system that just replacing the mech fan clutch isn't going to solve.
having the water pump fan running 'hot' will pull in more air than intended.....which should 'help' your other overheat symptoms. Kseal? sounds like something that clogs the radiator passages......

Well so far I’ve gone with the suggestion of ordering new fan clutch for starters. I don’t think there’s anything else going wrong with the cooling system because it’s been working fine all along (with the exception of the 1 condenser fan not working) but my a/c still blows cold and the gauge didn’t start going up unless it’s daytime, 95 degrees and traffic stop and go. So far it has only did it 1 time.

The reason I did k seal back in December, in cold weather I was having issues with coolant being burned on startup, and even a temperature gauge going up even though it was 3 degrees outside. Head gasket issue was suspected. K seal has good reviews, so I poured it in and the problem was solved.

Something causes my engine to misfire and knock when it’s much below freezing, while starting up from sitting overnight..the colder it is, the worst it gets. Fuel fumes spill into the cabin, and the engine usually stalls after running at only 500 RPM for a few seconds. The underside of the exhaust had even started smoking one morning while I was trying to warm it up.

I know that’s off topic, but it’s just one of the mystery annoyances that I haven’t bothered to diagnose...especially considering it never does it in warm weather.

Since then, I removed and flushed radiator while doing a/c condenser, and changed 2 radiator caps...

Update: turns out fan clutch was seized up. Somehow the pressure also blew up the top radiator cap.

But just when I thought I was ahead by changing the clutch, which works...the water pump belt also shredded itself. Seems the fan clutch wasn’t probably having issues for awhile because I noticed the water pump belt looking like it had some tears in it a few weeks ago. But it literally didn’t shred until we just put the new fan clutch on.

So now I’m just in a funk. I don’t know if I want to tackle doing the water pump belt myself, take it somewhere to be changed (and being in an unfamiliar area, who knows how much it could be), or just cutting the water pump belt off for now, and waiting til I get to a familiar place.

Oh wait, I just realized I can’t cut the water pump belt off and go anywhere, because that connects the fan and alternator to the crankshaft.

Which water pump belt? crankshaft to pump or pump to alternator? Those 2 belts are not extremely difficult, but they are tedious, and you have to remove all the belts to get to the crankshaft/water pump belt.
part numbers:
BELT- NISS#A1720-6P002
BELT- NISS#A1720-1P102

Did you spin your tensioners, and are they smooth and quiet?
What about the water pump itself? bearing turn smooth?