driving in high temps / cooling fans

[08Datsun]

I took the family in the PF out to AZ yesterday. The temps were in the 115+ range for a couple hours of the trip. The electric fan was on every time we stopped. One time, we stopped out near Hope, AZ and left PF running while we stretched our legs. After a couple of minutes, the electric fan kicked up to turbo jet levels. Apparently the PF electric fan is a two speed.

Oddly, the mechanical fan clutch never engaged. It seems that these were the type of conditions you'd hear that thing roaring. I'm wondering what it would actually take to heat it up enough to engage if 115 degrees with the A/C blaring and the PF fully loaded didn't do it. Has anyone heard their fan clutch engage?

The temperature needle never moved the entire trip. The A/C was working overtime, though. We only have the single system in our "S".

[markspath]

Are you sure you would notice if the mechanical fan was engaged? I remember, back in the old days, that was all we had on cars and I don't remember any difference in noise between the fan clutch being engaged and not.

But anyhow, it's nice to know the temperature gauge never moved, even with the AC full blast. I'm driving from NJ to Moab starting this Thursday, pulling a 5,000 lb trailer. I've been a little concerned about how my 07 SE will handle the heat.

[Gray]

The electric fan was on every time we stopped. One time, we stopped out near Hope, AZ and left PF running while we stretched our legs. After a couple of minutes, the electric fan kicked up to turbo jet levels. Apparently the PF electric fan is a two speed.

I heard the electric fan kick in a couple times last year when the truck was idling after a run with the AC on, normal operation I think. Somewhere I read to kick the AC on every week even during the winter to keep everything moving and lubed.

I'm driving from NJ to Moab starting this Thursday, pulling a 5,000 lb trailer. I've been a little concerned about how my 07 SE will handle the heat.

Being new everything should work great. About the only suggestion I'd have is to go to one of the Box stores, buy some nylon window screen material, remove the front grill, drape the mesh down in front of the rad and transrad and tie it to the top with some nylon string to keep the midwest grasshoppers and bugs from plugging off your radiators.

If you want some extra engine protection before leaving change your engine oil from 5W30 to a synthetic 10W40 which will give a HTHS number of >3.5, to keep your engine bearings with a good film as they are going to be working hard for the next few days.

If you're worried about transmission temperature go to one of the automotive places and get a stick on the side temp sensor and wire in a gauge to the dash, or you might be able to find a remote temp sender for reasonable, you'd have to check with a dealership as to what normal operating temp for the trans is.

If you have time you might want to change your rear differential fluid for new synthetic 75W90 to reduce heat and wear in that, on the SE model the front diff shouldn't be doing any work. If you can find an ester synthetic for the rear diff better yet as the diff will run a lot cooler. Whatever oil you put in should not be designed for limited slip; ie: ask for differential oil for non-limited slip application, limited slip diff oil has an additional friction additive. Think Motol, Redline, Amsoil and maybe some of the Mobil synthetics. A synthetic 75W110 or 75W140 that might even be better for hauling and rear gear protection, if planning on driving slow.

If you're going to use the roof rack for hauling as well you might want to build an air deflector at the front of the rack out of plastic, Corplast, etc to deflect air over the top of the trailer.

If you already installed a load stabilizing tow hitch and some air bags in the rear springs, fill your rear tires to max sidewall pressure, point 'er to the west my friend and happy travels.

.

[08Datsun]

Are you sure you would notice if the mechanical fan was engaged? I remember, back in the old days, that was all we had on cars and I don't remember any difference in noise between the fan clutch being engaged and not.

But anyhow, it's nice to know the temperature gauge never moved, even with the AC full blast. I'm driving from NJ to Moab starting this Thursday, pulling a 5,000 lb trailer. I've been a little concerned about how my 07 SE will handle the heat.

When you first start the PF in the morning, the fan clutch roars for maybe two seconds. Thats what it should sound like with the clutch engaged. I bet the system is up to the challenge for 5,000lbs. Hopefully you've put in the air bags like Greybrick was talking about.

I did a little checking on the fans in the 2006 FSM here on the forum as I'm not at home to check the 2008 FSM. The electric fan is indeed a two speed. It comes on high when the engine temp gets to 221. The low speed depends on the engine temp, A/C usage, and vehicle speed. It a bit odd that the temp gauge never moved and obviously the engine got up to 221 degrees.

The FSM doesn't say much about the fan clutch, only to make sure it isn't leaking and there's no play. I guess perhaps it comes on at an even higher temp. I just want to make sure it works when it is supposed to.

[amr40509]

How was this trip?

I just saw this post, I tow a 4000+lbs boat in the summer. Even on 100F days pulling up E. Kentucky's little mountains I've never had a temp issue. The electric fan does kick in, especially when messing around at the ramp, but no problems.

My '78 Bronco has a 400cid V8, and it gets HOT messing with the boat. The little 4.0L in the Pathy does just fine.

[LittleStevie]

When you first start the PF in the morning, the fan clutch roars for maybe two seconds. Thats what it should sound like with the clutch engaged.

I'm not sure that this statement is accurate. The roar is more due to the elevated RPMs just after startup.

My understanding of the fan clutch is that it's thermally activated, and progressively tightens as the engine compartment heats up. There aren't any solenoids or electrical controls, and it's not an either/or situation. I agree with MARKSPATH, I doubt you'd hear much difference between fully engaged and fully disengaged.

[08Datsun]

The trip went fine and the PF handled it easily. The total mileage was 1,250 miles. We were loaded with four of us, alot of stuff inside, and three bikes hanging off the back. We spent a week in Prescott AZ where the PF got some time on the back roads of forests in the area. The PF is an excellent road trip vehicle and gas mileage was 20-21.

There was a heat wave on the way out and the temperature was crazy hot. Getting out of the car almost made my contacts dry up and fall out of my eyes. The glass was too hot to touch from the inside while driving. The way back was a more manageable 100-105. There were no temp issues with the PF at all. There was a lot of mountain driving in the heat and the PF really didn't care at all.

My questions about the fans was simply to see what others might have experienced in these conditions. I've only had one other vehicle with electric fans and that is my Maxima. I have have tons of experience with fan clutches as every truck I've ever owned has had one. One I did a fan clutch conversion from a fixed fan, and have even modified one so it would come on at an earlier temp. They all make some noise when they engage, some more than others depending on if they are standard or heavy duty style. The noise on start-up is typical as the silicone fluid gets re-distributed to where it is supposed to be(it settles overnight). I just though it odd that the electric fan was doing all the work and the much bigger mechanical fan never engaged.

[markspath]

FYI, I am in Moab now. It was 105°F on the way in pulling the trailer through the Rockies. The fans were blowing full speed, making quite a racket. But they were obviously doing their job, as the temp gauge never moved above normal.

Ditto today while off-roading. It was 110°F in the shade, but no shade to be found on the trail. A/C was set at MAX COOL and we were in LOW 4WD for 6 hours, going up and down some relatively steep, rocky inclines (not too rocky -- see my thread in "Road Trips" for details). Again, the temperature gauge stayed in its normal place (I'm beginning to wonder if it's cosmetic ).

[me&pathy]

the pathfinder has always ben good about temp control with the ac on full blast and the rear air on its never given me any trouble even when being pushed in 110 temperature's

[08Datsun]

FYI, I am in Moab now. It was 105°F on the way in pulling the trailer through the Rockies. The fans were blowing full speed, making quite a racket. But they were obviously doing their job, as the temp gauge never moved above normal.

Ditto today while off-roading. It was 110°F in the shade, but no shade to be found on the trail. A/C was set at MAX COOL and we were in LOW 4WD for 6 hours, going up and down some relatively steep, rocky inclines (not too rocky -- see my thread in "Road Trips" for details). Again, the temperature gauge stayed in its normal place (I'm beginning to wonder if it's cosmetic ).

Could you tell if it was the engine fan or just the electric one? The engine fan would rise and fall with engine speed.

We just got back tonight from another trip. This one fully loaded in the PF with three bikes on top, and a 2,000lb tent trailer. It was only 80 degrees at the most, but it didn't even make the electric fan come on. I guess we have nothing to worry about.

Cooling is one of those things I really like to know are solid on a vehicle as you can tell. If your cooling system isn't up to snuff, it can put you in some really bad situations. In the old days you had to modify even a tow package equipped vehicle to use in ultra high temps and trailering in the mountains.

[markspath]

Could you tell if it was the engine fan or just the electric one? The engine fan would rise and fall with engine speed.

I assume that every fan in the truck was blowing at full speed, even when idle. The amount of noise coming from the fans was impressive, but even more impressive was the fact that even off-roading in 4WD LOW with about 1,000 of passengers and gear in 110°F heat, the temperature gauge was right where it would be under normal driving conditions.

The only comment I have is that when I had the oil changed and tires rotated, they said I was 1 quart low on coolant (which I had them add).

I don't think there's anything for you to worry about. It seems the Pathfinder could pull a locomotive across the surface of the Sun without overheating.