Fan blade orientation?

[snijd]

Could some kind soul tell me which way the fan blades are oriented behind the radiator? Should the rounded (presumably leading) outside edges of the blades be toward the radiator, or away from it? Just ruling out a possible source of a cooling problem. Thanks!

[kohnen]

The inner part of the curve of the fan blades faces the back of the car.

[andyprius]

Originally Posted by kohnen

The inner part of the curve of the fan blades faces the back of the car.

It's possible to put them on backwards????

[snijd]

Evidently it is possible to reverse them.

See:
Longo Toyota tells me Prius overheating is *normal*!?

It looks very much like mine are both reversed. That would explain why the outside air temp seems to climb to unreasonable levels at the same time the A/C stops working, and the overheat warning comes on. The airflow is not correct.

I guess it's possible I'm just looking at them wrong, but they certainly look like their orientation is not correct.

[kohnen]

Originally Posted by snijd

Evidently it is possible to reverse them.

See:
Longo Toyota tells me Prius overheating is *normal*!?

It looks very much like mine are both reversed.

You're most welcome!

Another possibility: This used to happen to me on my -cough- GM -cough- cars: When the fan motors started to fail, they failed because the brushes on the motor wore out. This would cause them to turn slowly, and intermittently. If you ohm tested them, they tested good. If you powered them up, they spun, but more slowly than they should.

After replacing the fan motor, and opening up the old one, it became apparent what was happening - the worn brushes were at the end of their spring travel and would touch the commutator very lightly.

Don't know how many miles you have on your Prius (or whether the Toyota motors last longer) but this might be a possibility.

[snijd]

Thanks for the reply. I PM'd you with a more detailed question, but I guess I'll throw it out here. Just wanted to make sure I understand that the pointy corners of the blade tips are on the trailing edges of the blades (like an airplane propeller). On my car, these are facing the radiator. That seems backwards, since the fans are behind the radiator.

Since the car only has 20,000 miles, I wouldn't think the brushes would be very worn yet. I tried to get the car into inspection mode, but didn't get anywhere with that. If I could get the fans to start, I could easily determine whether everything is correct--but it sure looks wrong right now.

The only reason the car isn't at the dealer right now is that I'm awaiting arrival of the new warranty paperwork. Wonder how quickly they would have sorted this out, though.

[andyprius]

Originally Posted by snijd

Thanks for the reply. I PM'd you with a more detailed question, but I guess I'll throw it out here. Just wanted to make sure I understand that the pointy corners of the blade tips are on the trailing edges of the blades (like an airplane propeller). On my car, these are facing the radiator. That seems backwards, since the fans are behind the radiator.

Since the car only has 20,000 miles, I wouldn't think the brushes would be very worn yet. I tried to get the car into inspection mode, but didn't get anywhere with that. If I could get the fans to start, I could easily determine whether everything is correct--but it sure looks wrong right now.

The only reason the car isn't at the dealer right now is that I'm awaiting arrival of the new warranty paperwork. Wonder how quickly they would have sorted this out, though.

Not totally understanding the symptoms, it should be easy to get the fan on by running the engine for 5 min. or so, perhaps less, with everything on! When the fans come on, the airflow should of course be thru the radiator and over or past the ICE. Of course if the dealer is going to fix it free, you have nothing to worry about. It seems to me that normally the construction of the fan is foolproof and does not allow backward installation. Pure conjecture. I'm assuming that like an airplane wing, the leading edge ( closest to the radiator) would have the greatest curve. PS Should you attempt to hang a kleenex to the front of the radiator, it should be sucking the kleenex on to it.

[andyprius]

An interesting thread from April. UNLESS you had major repair to the front end I would say fan reversal is not causing your overheat problem.

[snijd]

For whatever reason, they're on the wrong sides, and facing the wrong directions. The 7-blade fan is on the left, and the 5-blade is on the right. Should be the other way, as I observed on another 2006 model today. Since they spin in opposite directions, they are actually working against the natural airflow when the vehicle is in motion. The most difficult part of this is getting the whole fan assembly removed so I can move the fan blades around. Looks like the radiator hoses will have to come off. Hopefully the inverter hoses can stay put.

[andyprius]

Originally Posted by snijd

For whatever reason, they're on the wrong sides, and facing the wrong directions. The 7-blade fan is on the left, and the 5-blade is on the right. Should be the other way, as I observed on another 2006 model today. Since they spin in opposite directions, they are actually working against the natural airflow when the vehicle is in motion. The most difficult part of this is getting the whole fan assembly removed so I can move the fan blades around. Looks like the radiator hoses will have to come off. Hopefully the inverter hoses can stay put.

If you are correct, the partial disassembly of the radiator cooling system and the inverter cooling system requres some knowledge of correct coolants and getting all the air out of both systems. Do you have some sort of manual? If the car is still under warranty? You might want to allow the dealer to work on it. Did you buy the car new?