Converting from belt-driven fan to electric fan

There are people down here below the age of dirt....LOL

hahaha. The 4Y engine was on a RWD Toyota Crown and not a minivan and much more a forklift.

Sounds like your fan clutch, thermostat, or possibly both are sticking. I havn't tried it on a Subie but on my Explorer the fan clutch is easy to test. With the engine off and cold you should be able to turn the fan with your hand. With the engine off and warm you shouldn't be able to turn it. I'm with the others in saying that switching to an electric fan doesn't seem like it would buy you over the existing system assuming it were working properly. I also don't see why you would gain any milage since the energy to turn the fan still needs to come from the engine but now with an extra conversion to electricity at the alternator and then back to mechanical energy at the fan motor. Every conversion will lose you some effeciency so I'd expect the electric fan to actually use more gas rather than less.

That's what the clutch on the engine-driven fan is for.

Then fix the THERMOSTAT instead of spending all the money for an electric fan. The fan isn't what's making the engine get too cool, its a bad thermostat.

But even with the clutch, the fan is always spinning. It never completely stops. And with the weather here being in the single digits, air movement other than from driving is not required.

Thermostat's cool. When the car is running at a constant speed, or even stop and start driving, the temp satys rock-steady. Only if I park for more than 2 minutes does the temp drop.

At these temps, it seems even airflow from the fan idling is enough to cool the engine.

Thermostat seems OK. Haven't checked the fan, but my experience with Jap cars is that if they go bad, they tend to idle rather than stick.

But, you bring up a good point...when I get it back from having the timing belts changed, I'll check the fan...($180 rather than freezing my @$$ with the car on jack stands and my work area a sheet of ice? I'll pay the $180...)

I

See my reply to Steve. We had one week in the 40's, one week in the

60's!!! and have been in the deep freeze ever since. I don't even think the fan is needed at this point!! ;)

Ahhh yes, but when you are forcing air through the radiator in excess of what the fan draws when not moving, the fan is not drawing much power, it is more like a windmill at that point. Again, if you have a properly operating viscous clutch, the fan isn't going to draw significant power. There is a certain amount of drag from the clutch that causes the fan to rotate, but the power draw is tiny. If you want to get into diagnostics, you'll need a variable strobe light. You adjust the strobe until the fan appears to be not moving and then compare that rpm to the engine rpm.

It still seems to me that there is a problem with the thermostat. Have you verified operation of the fan clutch? One possibility is that the clutch is frozen. There really should not be much difference between idling and driving at moderate speeds as far as cooling is concerned. I am surprised that the fan over-cools the car at idle, but you don't experience over-cooling car when cruising at a steady 35 mph. Have you actually tested the thermostat, or are you just assuming it is OK because it seems OK when the engine is under load. It is possible that the thermostat does not completely close so it cannot regulate temperature at the low end. For the cost of a thermostat, I'd try a new one before going overboard and installing an electrically operated cooling fan.

Ed

The proper and working thermostat will 'close' and force the engine to stay at it's setting of say 195F when you slow down the engine so you keep the heater working, a broken thermostat will allow the engine to cool down so you lose internal heat.

I just changed one like that in my Jeep and in a friends car, they were broken 'open' so we couldn't keep heat up.

Thermostats are backward to what some think, they set how 'cold' an engine can run, not how hot.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:

I'm not sure how you got onto the power issue. His problem is heat.

He wants to remove the belt-driven fan and replace it with an electric fan. His idea is that the air flowing from the moving fan slows the rate if heat-rise, and if he can remove the belt-driven fan then he will get heat faster.

I think his idea is flawed, and I would not consider it. But, I live where bitter cold comes on when the thermometer hits 60 and stays there all day.

There is a certain amount of drag from the clutch

I agree with your assessement on the tstat. I think the tstat is the trouble, but I think it is sticking open. An open tstat cause the cooant temp to fall, when the coolant temp falls so much that the needle moves below the mid-point, then the tstat is stuck open. When the car is moving, there is work being done that generates heat, and the heat can overcome the stuck open tstat, keeping the temp in a normal range. But, when the car stops moving, the work stops, and a stuck open tstat can take out more heat than is being generated, the result being a falling needle on the guage.

>

Another common mistake is in thinking that a tstat opens in a drive cycle, then stays that way. A tstat opens and closes repeatedly throughout the drive cycle.

That's deceptive, though. Aeordynamic forces usually increase as the cube of velocity, so while the fan may appear to be spinning fairly fast, it may be drawing virtually no power from the engine. The loudness of the fan is a better indicator- on my car the fan will roar quite loudly at fast idle, then go completely silent when the clutch disengages.... but the eye can't really see any difference in the speed of the fan.

Then the thermostat is BAD. The temp should never drop if the thermostat is doing its job. That's the whole point. What its probably doing is sticking open rather than closing smoothly as the temperature of the engine decreases. When the engine finally gets cold enough it will snap shut, but that's not how its really supposed to work.

I don't doubt that. But the problem is still the thermostat if the engine temperature falls below the normal operating temperature once its gotten up there in the first place.

Or even open in the real cold...

I went to the beer store yesterday at -12C. The store is about a mile and half away. I watched the computer gauge readout on the console in our GM V6 car. I had heat on the way there, but only as I was getting there, then I was back home in the driveway with lots of heat as the temp hit 190F which meant the 192F T-stat hadn't opened nor had the electric fan turned on.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:

I agree with the sticking thermostat idea mostly but no one has mentioned that the engine block itself does lose heat as it is a large chunk of metal with cold air flowing over it. The outside temp at which the t-stat is fully closed but due to heater core and direct heat loss the engine starts to cool down below normal operating temp varies and is usually well below 0° F but it is still a very remote possibility.

Hachiroku,

Make sure you're not confusing the thermostat with the temperature guage. The guage on your dashboard may accurately tell you the temperature of you engine coolant, but it will not tell you if the thermostat is opening/closing correctly.

I used to drive a Subaru Loyale in Fairbanks, Alaska and regularly experienced temperatures downwards of -40 degrees. Before leaving my cabin in the morning, I'd let it idle for five or ten minutes and it would warm up just fine.

The volume of air moved by the fan is pretty small compared to the volume of air shoved through the radiator when the car is in motion. (Granted, your engine is also making more heat under load, but it's still making plenty at idle). You're engine temperature *shouldn't* drop when idling, which is why so many posters are urging you to check out your thermostat, the most likely culprit.

Regards, Dave Riesz

The Crown hasn't been sold in the U.S. for quite a while, and it had a M series engine back then. Obviously, your aunt isn't in the U.S.!

Well, I think whatever is going to have to wait! Although I will try the thermostat. I didn't *think* of being stuck *OPEN* !!!! :0

I took it to have the timing belts replaced. Timing belts are almost new...

Head gaskets are leaking...

Looks like Steel Seal for this one!!!