Engine temp bewilderment
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Engine temp bewilderment
I have reciently changed the thermostat In my 94' 3.0L Aerostar, To try and relieve a high temp problem. The temp crawls to the High end of the temp gauge while in traffic, But when at expressway speeds or streatches of uninterupted traffic, the temp falls to the cold end of the gauge. So far it has not overheated, but this puzzles me! How can it run hot, but when allowed to run, runs COLD. Is my water pump losing flow? what checks can I try?
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Sorry, I should have mentioned that the first thing I checked was the fan. Ichecked for airflow while parked in the driveway, then shut off the engine and manually rotated the fan, the clutch seem to be tight, it won't freewheel at all .
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From: North Jersey, New Jersey
Did you check your oil and coolant levels they all ok?
If they are the fan clutch is probably the culprit its job is to control the speed of the fan regardless of engine speed at high temps the clutch tightens up to spin faster with the engine and at low temps to slip a little reducing its speed.
If they are the fan clutch is probably the culprit its job is to control the speed of the fan regardless of engine speed at high temps the clutch tightens up to spin faster with the engine and at low temps to slip a little reducing its speed.
Postmaster
Joined: Sep 2003
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From: Southern California
I have a '93 and a '95 Aerostar. The temperature senders on both of them went bad. These things go bad more often than we think. Also, the connector plug is not the best in the world. Both my temperature and oil pressure gauges acted up frequently, and I'd have to go crimp down on the plug, clean them up and put a dab of silicone grease on them to get them to work again.
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I had a similar problem (hot in stop/go traffic cool on highway) and it turned out to be the fan clutch. It seemed okay by looking, listening and turnign it by hand, but looks were deceiving - it was bad. Still wasn't convinced until I put the new clutch on.
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From: North Jersey, New Jersey
Also as I recall there are special tools to remove the clutch you can rent they're not mandatory but they make the job easier also remember the clutch has a left hand thread you must turn clockwise to loosen it.
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Joined: Feb 2003
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From: Tottenham Ontario Canada
My Aerostar had the same problem three years ago. It was the water pump.
I had tried everything else first (T-stat, rad cap, flushed the system, etc.) & the problem stayed. The pump was the last thing to change.
There were no blades left on the impeller. I am not sure how it still managed to pump ANY coolant (convection and good will?) at highway speeds, but it did.
After I changed the pump the temp always stayed rock steady.
A vice-grip chain wrench gets enough grip on the fan shaft to loosen it from the pump. And they are useful for other projects, too.
Cheers,
Eric
I had tried everything else first (T-stat, rad cap, flushed the system, etc.) & the problem stayed. The pump was the last thing to change.
There were no blades left on the impeller. I am not sure how it still managed to pump ANY coolant (convection and good will?) at highway speeds, but it did.
After I changed the pump the temp always stayed rock steady.
A vice-grip chain wrench gets enough grip on the fan shaft to loosen it from the pump. And they are useful for other projects, too.
Cheers,
Eric
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From: staten island
When I first switched my thermostat, I used a NAPA. The problem worsened. Then I used a Stant, things got a little better. Finally I used a Ford and the temperature swing is much less. Try to stick with the Ford. If it dosen't improve, suspect the water pump.
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Joined: Sep 2004
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From: earth
I used a NAPA thermostat on my Toyota 22R engine, the temp swinged like your case and 2 mos later I lost the engine (crack the head or block).
I used NAPA on my Ford Diesel van and the engine become overheat, I switched to Stant and it's been good
I change the 185 deg. Stant on my 94 Aero, it has worked good. The temp is around the N. My Ford dealer doesn't offer 185 degree thermostat for my diesel van or Aerostar.
I used NAPA on my Ford Diesel van and the engine become overheat, I switched to Stant and it's been good
I change the 185 deg. Stant on my 94 Aero, it has worked good. The temp is around the N. My Ford dealer doesn't offer 185 degree thermostat for my diesel van or Aerostar.
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Originally Posted by Fordboy49
I used a NAPA thermostat on my Toyota 22R engine, the temp swinged like your case and 2 mos later I lost the engine (crack the head or block).
I used NAPA on my Ford Diesel van and the engine become overheat, I switched to Stant and it's been good
I change the 185 deg. Stant on my 94 Aero, it has worked good. The temp is around the N. My Ford dealer doesn't offer 185 degree thermostat for my diesel van or Aerostar.
I used NAPA on my Ford Diesel van and the engine become overheat, I switched to Stant and it's been good
I change the 185 deg. Stant on my 94 Aero, it has worked good. The temp is around the N. My Ford dealer doesn't offer 185 degree thermostat for my diesel van or Aerostar.
Thanks Again!
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Bewildered
Originally Posted by roree
When I first switched my thermostat, I used a NAPA. The problem worsened. Then I used a Stant, things got a little better. Finally I used a Ford and the temperature swing is much less. Try to stick with the Ford. If it dosen't improve, suspect the water pump.
Thanks again!
Ed