The water temperature in my 97 3 liter Aerostar seems to be higher than I would expect when climbing a mountain road with the aircon on full. It was only about 75 degrees F and the elevation went from 300 feet up to 2,400 and the gauge was at 3/4 to the red zone.

I don't use aircon much here in the south San Francisco Bay Area but as I recall the gauge on both my 96 and 97 Aeros was straight up during such climbs. The 96 is out of coolent so I can't compare it now.

The reason I'm rather concerned is we are about to leave on a 2,500 mile road trip with 4 people and lots of gear through Nevada and Utah and we'll climb a lot of passes in 90 degree heat or higher.

I don't want trouble in the desert! Last year the alternator went out on Memorial Day on I-70 and we limped through the desert for 5 hours until we found a shop to R&R it the next day. Mostly no cell service out there. Stressful and expensive.

The mileage is about 135k and the water pump was replaced about 2 years ago. The radiator was replaced at about 100k.

Any ideas?

Jim

 

1. defective sticking shut thermostat or not opening fully.
Motorcraft 190d F MOTORCRAFT Part # RT1161(comes with the grooved rubber seal) if you can find (RockAuto internet) one or Stant Premium Stainless steel 195d F if the MC is not avail. in your area. Ford is making MC go away at corporation decision level, why? cost savings.

2. air in cooling system. park with nose at least 2 ft higher than rear.
with rad. cap off, let run. will self burp. make sure the small hose from rad. cap neck opening to overflow bottle is tight on rad. connector. best to put wire tie over hose as a clamp to prevent air pull in when engine cools off.

2. worn out fan clutch.

4. plugged radiator/engine from running tap water. makes lots of scale slime that plugs small passages. use a HD cleaner.

5. old weak rad. cap not holding pressure or torn seal.

6. plugged fins on rad. from bugs and road crud

http://www.prestone.com/products/print/379?popup=1

use only distilled or deionized water ONLY in these. you'll have better luck finding the distilled.
if you can't trust the water, then the 50/50 premix coolant only.

 

Wow, amazing response 96_4wdr! Thank you, plenty to work on!

Motorcraft brand being dropped? Sad. My grandparents gave me their 55 Ford Club Sedan in 1967 when I turned 16 and I've used a lot of MC products over the decades.

The radiator of my 96 Aero blew out yesterday on the same mountain road I mentioned in this post. I managed to limp into a repair place. $320 with new thermostat also. Must be my year for water issues :-)

- Jim

 

Jim,
Your radiator also serves as the heat dump for the transmission. Tranny fluid is circulated on a separate circuit through the radiator. Climbing hills will heat up the transmission adding additional heat load. The condenser coils for the AC system sits in front of the radiator. As heat from AC is given off, it is blown right back onto the radiator. Its a wonder these poor engines survive as well as they do in summertime operations. Normally there is sufficient cooling capacity to prevent the problem you are seeing, so something must be amiss.

As Cliff has pointed out already, there are many items that may be contributiing to the engine running hotter than usual. I would consider the fan clutch a high probability item. Fairly inexpensive to replace and hard item to diagnosis. Bite the bullet and get a Motorcraft if you can. I have not had very good luck with aftermarket replacements. They work.....for a while.

Climbing without the AC on an older engine is a good idea. Having an alternator fail is not as bad as blowing a head gasket from overheating. Lastly, make sure both the radiator AND the coolant overflow container are topped up. If you get any air in the cooling system, the air gets trapped in the uppermost part of the engine which happens to be the coolant temperature sensor. This causes the gauge to fluctuate as the air is purged then trapped again. Usually you see this condition right after opening the cooling system. Eventually, the system purges itself.

Good luck on your trip. We used to take the kids from Colorado to the Outer Banks in NC several times in the Aero. They have lots of memories of those trips....not necessarily fond ones!

 

Thanks aerocolorado! More background info helps!

I had a little work done by a Las Vegas Ford dealer long ago and he said that aircon was his only complaint about the Aeros. He said Ford engineers came to LV to try to find solutions (yeah, sure!). My 97 Aero is dark green and I'll never have dark again. Too hot in the summer. Our mocha 96 is much better but too old for a big trip.

We'll be in the wonderful Colorado Plateau rocks soon! Wish I had time to mountain bike in Fruita!

 

When I worked for Ford, we did send a lot of cars to a proving ground near LV for hot weather testing. That Ford dealer was not lying to you.

Good luck with your cooling system repairs.

 

Xlt4wd90 - I didn't think the dealer was lying at all. He shared deep knowledge of the aircon issue with me. I received great service there! Still, my guess is that escaping Detroit area for Las Vegas would be an engineer dream :-)

I go to real conferences in Las Vegas but it seems that no one believes me. Mention that you are really working when in LV and the harassment is endless :-)

 

Indeed the stories fly when your co-workers find out you went to LV for work. One of our engineers came back from a week of testing, and submitted his expense report. He spent the weekend at Cesar's Palace, and caught a lot of ribbing for the extravagance. He said it was sort of a compensation for spending a week in the hot dry desert setting up instrumentation.

 

tough to get decent high cfm cooling air flow thru the engine bay of the Aero. 3L probably better than the hunk of iron 4L for more air flow.

we've done the trick of switching the A/C on and off climbing a mountain pass or crossing the Southern deserts. still remember how hot the floorboard got going across Death Valley at 109d F.

luckily the old Aero girl has seen her last trip into the deserts or towing over a 12,000 ft mountain pass. she just putt putts to dog shows or the mail now.


get a large plate/fin tranny cooler mounted up front to take some heat load off the tranny. put the tranny down into 3rd, OD off, on the hills and try to keep it in torque converter lockup. far less ATF fluid friction heat produced in the TC in lockup. put a lockup switch on mine years ago

 

Thanks for the transmission advice 96_4wdr. I hope I don't have to go that far. Your list goes to my mechanics this AM. I can't do my own repairs where I live.

Probably the highest pass we hit will be around 6k on this trip unless we return home through Yosemite or Tahoe. Our 96 Aero has been in the Yukon at 60 below and the Death Valley at 120. Never had a problem. Used just for local drives now.

Last year the alternator on our 97 died on Memorial Day in the middle of nowhere Utah. I managed to limp along for 5 hours until I found a town with a repair shop plus hotel that is near a big enough city for parts. I try to avoid such situations but forgot about preemptively replacing it.

 

Not so, the 4.0L is actually slightly smaller than the 3.0L, though the difference is subtle. The 4.0L gets better airflow, and from the factory comes with a larger more efficient radiator. The 4.0L is capable of producing more heat however. Finding good after market radiators is getting tougher. Last summer my radiator was replaced due to leaking. The replacement does not work nearly as well as the old one. I am looking at replacing it again, because the cooling efficiency is so poor. The radiator I wanted installed was no longer available, seems most of the ones on the market now are price oriented, and cooling efficiency is not a high priority.

I do strongly believe in better coolers. And yes, if your trans is hunting for gears or the torque converter is coming unlocked, you need to be in 3rd gear. An unlocked torque converter produces a lot of heat, especially in OD, far more than a trans cooler can dissipate. I drop my OD whenever I am going up a hill that I know 4th won't hold. Stacked plate type coolers are better than tube and fin coolers. They transfer heat more efficiently, allowing you to use a smaller cooler, and allowing a larger cooler to dissipate more heat. The best place to mount the cooler is in the bumper area where the stock one went. This is tricker to do, but allows better cooling, and does not compromise the airflow through the AC condenser and radiator.

 

The shop I used replaced the thermostat, fan clutch, and flushed the radiator as suggested by the Aerostar guru 96_4wdr. I tried climbing the same hill at the same outside temperature as mentioned in my first post and the temp gauge never went past straight up this time. These solutions seemed to work but the big test will be a fully loaded Aero with 4 people and camping gear in the deserts of the Southwest soon :-) The big test will be that long climb going west out of Death Valley in June.

 

I agree, the real test is yet to come, but it sounds like the problem has been resolved. While its not really a FIX, it can be used without problems, and that is to use something like Wetter Water as a cooling system additive. It can sometimes cause leaks (only very slow seeping, not enough to worry about), but if it doesn't, it does work as advertised. It noticeably lowers engine temps.

 

Thanks KahnTyranitar. Products that make water "wetter" are usually soap. I've used thousands of gallons in another application. Should be harmless.

 

Something else to consider is that ethylene glycol does not conduct heat as well as plain water. The Mustang road racers use plain water with Water Wetter to enhance heat transfer (and lube the pump), and they don't have to worry about freezing. Since you're going to drive in hot weather, you don't really need the freeze protection, just the anti-corrosion protection, of the anti-freeze.

Since I don't worry about freezing in Southern California, I usually use only 1 gallon of anti-freeze with a bottle of Water Wetter in my cooling system.