Fan blade orientation?

Hi Rob,

Thanks for providing a very detailed writeup about your work.

The Toyota repair manual is silent regarding the correct fan rotation direction. The exploded parts diagram shows that one fan has seven blades while the other has five blades, but you have to look closely to note this. Prior to reading your posts, I had assumed that the two fans were the same and rotated in the same direction.

 

Yikes! One fan goes to the left and the other to the right! Is there some sound technical reason for Toyota to have done this or is this political correctness run amuk?!?!



Seriously, first place award for troubleshooting above and beyond the call of duty!

:first:

 

You surprise me! :evil:

Do you ever realize that on multi-engine prop planes, they have counter-rotating engines / props to decrease torque so the planes won't spiral out control? lane:

Well, Toyota, in their infinite wisdom, used the same engineering analysis and made counter-rotating fans? :doh:

Word has it, they will follow suit in the 2010, and have the front wheels rotate opposite of the rear wheels! :bounce:

 

I really need your help. My car was involved in a crash... everything was repaired but one of my fan blades got damaged on the right fan so half is broken. I thought it was not important since its only one blade so I tried to cut corners and told body guy to put it on. Now, I regret that cause when you turn on a/c which turns on the 7 blade fan, there is a vibration due to the 1 missing blade out of the 7. Now, I know it is a pain to remove and change... I got the new fan and want to put it on from the bottom. Can you please tell me how to do this?


How do you remove the shroud so I can change the fan?


Please help.

 

Rob,
Thanks for the job description, especially the part about the fan nuts being 8mm. I was able to swap them by just removing the fan housing bolts. I had just enough room to squeeze an arm between the radiator and housing through the bottom. Lost some skin though.

Fccjben
John



Rob,

• Do the two fan motors have the same part number?

No--and the prices are different. One turns clockwise, the other turns counter-clockwise.

• I take it that you personally swapped the fan blades? What does this procedure require? How hard is it to remove the blade from the motor?

Yes, I personally did the work.

1. Removed the plastic fairings/covers beneath the radiator (I also removed the inner wheel wells, as it seemed easier than separating the other pieces), and the plastic pieces on top, in front of the radiator.
2. Removed bolts retaining radiator, on top and bottom.
3. Removed a couple of electrical plugs to make it easier to maneuver the fan housing so as to make room to reach up between the radiator and the fan housing with a ratchet to reach the nuts on the fan blades.
4. Loosened fan blades with 8mm socket on 3/8" drive--a long drive handle made it easier.
5. The fan blades came right off.
6. Reverse procedure to reinstall fan blades. The keyway is identical on both motors, making it easy to inadvertently reverse their position.

• Did you need to swap the two fan motors; or did you leave the fan motors at their original locations?

I left the fan motors where they were. To have moved them would simply move the problem to different locations.

• When looking at the fans from the rear of the car facing forward, which direction is each fan supposed to turn (clockwise or counterclockwise?)

Left: clockwise; Right: counterclockwise.

I am also surprised that this problem did not manifest itself to the original owner. This seems to indicate that the car suffered front-end accident damage and the fans were incorrectly installed?

Yes, this is very likely the result of maintenance performed on the vehicle, rather than an assembly line error. I wonder if the previous owner sold it to me because he was stumped at the vehicle's strange behavior--he certainly made no mention of it when showing me the car. It was surprisingly tolerant of the backwards cooling arrangement. The primary manifestation was the intermittent air conditioning. I only saw a high temp warning once, and only for a few seconds. I have no idea why he didn't get it fixed, since it was under warranty. Maybe the dealer was stumped, too? Seems difficult to believe.[/QUOTE]

 

Hi all,
Yes I bought a 2006 Prius from a dealer late 2009 here in Australia. It turns out that there are some telltale signs to this issue, but more than likely it's a factory fault on the 2006 model!

The front RHS foglight on mine was smashed - I thought it was a rock and didn't even notice it when I bought the car, but the reason it was broken was simple - all fan related.

The first I knew there was a problem, was in a Perth 42deg Celcius day where the Airconditioner just stopped working after a while. Sitting idle, sometimes it would start working again. Very strange considering there was a sticker under the bonnet (or hood?!?) saying that it had been regassed recently.

As it turns out, the airconditioner was the only real noticable issue - as it stopped working randomly - and then started again just as randomly after I had overheated inside the vehicle.

It turns out the fan blades on mine were reversed also - the 7 blade fan where the 5 blade was supposed to be and vice versa! This caused air to be blown at the wrong rate and in the opposite direction to the normal airflow when the car was in motion at 70KM/hr. The NET airflow through the radiators when moving was almost zero.

The fact that the fans were on full blast (parallel accross the 12v instead of the low speed series operation) meant that things were getting hot, but I wouldn't have noticed if it weren't for the A/c. Also the HOT air coming out the front of the radiator grill tended to superheat the RHS foglamp - so a splash of water one day probably just shattered it's glass. Now I know why.

The Toyota dealer was TOLD to swap the fans in a service and they only believed me after they saw the issue.

The vehicle has been running fine ever since and the A/C runs full time and now can freeze the passengers solid even in hot weather.

Looks like a common issue to 2006 Gen II prius cars - I don't know how long mine was like that but it looks like from new.

I found a picture on google and numbered everything, then emailed it to the dealer so they knew what I was on about.

 

This is indicative of a bad design, where it is possible for the fan blades to be swapped. I'd expect the fans to be designed so that the wrong blade won't fit on the wrong fan motor.

 

My 2005 Prius also had overheating issues during hot days in the summer and the AC would run warm. I had some front-end damage repaired a few years ago in the Spring and didn't put the two problems together until I did some research on PC. Sure enough, the autobody shop had the fan blades swapped. I turned on the car and AC and held a piece of tissue in front and behind the radiator and the airflow was forward instead of backwards.

Thanks for Snijd for his walkthrough. It turned out all I need to do was remove the top and bottom shrouds and then loosen the for bolts that hold the fan assembly to the radiator to access the fans.