Cleaning the Prius Hybrid Fan for Preventative Maintenence

should be a you tube somewhere. maybe luscious garage? or nutzaboutbolts. it does take a bit of time to remove everything, but worth it. they'll likely want a few hundred dollars for what may amount to an inspection only.

 

I think the general ruke of thumb, would depends on environmental conditions. Here I mean if you drive severely in areas where your car is regularly exposed to dusts and all that, it would be cool, to clean em up.

Dxta

 

once you see it after 110k, you'll have a decent idea of how often. a lot depends on who is in the car on a regular basis. kids, pets and etc. generally speaking, without any specific contaminant like fur, it's just a light layer of caked on dust.

 

The easiest way to figure out how to get to it is to dive in. You'll likely need to pull off the portion of seat back with the fan intake grill, and the hatch deck directly over the hybrid battery.

There's a video by @NutzAboutBolts pinned in the third gen maintenance forum, but I'm not sure how relevant it would be, to second gen. Watch it anyway, just to get an idea of the complexity?

Contrary to the video, I did not find it necessary to remove the rear seat cushion. The object with that is to remove one bolt that's holding the seat back portion with grill, but you can just reach in between seat back and cushion with some ratchet wrench extensions.

Clean all the ductwork with some sort of feather boa while you're in there. Also, I found the fan can be cleaned without complete removal.

 

A quick and easy thing to check is how much noise is coming from the fan. The cooling fan has 6 speeds, 1=slowest and 6=fastest. The speed is based on the battery temperature sensors. At speeds 1,2 and maybe 3, you'll hear almost nothing in the backseat. If you get to speed 6, you will definitely hear the fan running. If the fan is clogged badly enough to cause temperature control problems, you'll be in the easily audible area of the fan speeds.

After driving a bit to warm up the battery, try holding a piece of tissue paper/Kleenex or something similar at the fan suction by the rear passenger seat, you should see the paper pull toward the grille. With a good fan, higher speeds should equal higher noise and higher air flow. If it pulls slightly and you cant hear the fan, then you're probably on speed 1 or 2. Pulling hard and fan is very loud, speed is much higher. Pulling only slightly and with a lot of fan noise, then you probably have fan clogging issues.

 

Maybe third gen is quieter? I've never heard ours, even though ScanGauge reported it was up to speed 4 IIRC. To be fair this was from the driver's seat, driving, and I've been to one or two rock concerts.

 

Can this be best tested by keeping the car on in park and just listening or should I have a passenger in the back seat while on the highway accellerating to see what they hear?

If someone is sitting in the passenger side rear seat of your 2006, the cooling air inlet duct is right next to their right shoulder. That little grille is where air is pulled in. There's a couple more filtered inlets further back in the tubing, but that grille is the main supply. If your fan is running at a higher speed than 3, I would imagine anyone with an ear near that grille will easily hear it. At speed 6, you will very clearly hear it from the driver seat.

If it were clogged, you would probably be running at a high speed very frequently, trying to get air flow through the battery.

 

I think there's a hint in their quote: you don't want to pay high-priced mechanics to do this, strictly a DIY item.

 

Here's a photo of a dirty one. I took this on a recent battery replacement job. The battery was having no heat problems. The fan was dirty, but not clogged. It just shows that you have a bit of wiggle room in regard to fan cleanliness. I have had other ones that were a lot more packed full of pet hair and debris that had some minor temperature problems.

 

I just did this last week. I had no idea when it was last done on the new-to-me '08, so I figured I'd better look. After watching a couple YouTube videos, I dove right in and had everything apart in half an hour. Broke a couple of famously brittle clips on the way in, but that's just how working on old Toyotas goes.

Anyhow, there was barely a speck of dust to be seen. I didn't even bother unbolting the fan itself; there was no reason. Blew out the fan and the filters in the ducts with compressed air (if you don't own a compressor, one of those aerosol cans will do) and reassembled in half the time it took to get apart.

All in, well under 2 hours of my time. Spent $8 at the dealer for replacements of the clips I broke, and now I have peace of mind that it's clean.

Just do it.

 

(It's cold up here in the northeast currently...don't feel like doing car work in this weather!).

I feel your pain. Disassembling the rear interior can be a "break-a-thon" in very cold weather. Removing the very first piece of trim (the piece right by your knees if standing at the trunk) is required in order to remove the side trim panel. Cold weather=broken plastic retainers on this piece. Those are molded as part of the trim and are NOT replaceable. It's nice to be able to have this piece locked in place, as it also has a lip for supporting the storage tray.

 

Great points. I just came across this thread and was about to suggest waiting for warmer weather for those reasons as well as comfort.

By the way, at $500 for that service, you could have a part time summer job cleaning fans, undercut the dealer, and still get quite a bit of fun money.

 

Here's another before / after. Just a basic cleaning. I remember this one, as it was the first time I experienced a fan that wasn't pretty clean. I pulled it out of a salvage yard 2008 that had already had the battery removed. The fan was still mounted and untouched, so I figured I'd grab it to have a spare. About gagged when I looked inside of it.

 

What's the secret cleaning method?

 

I just use a Q-tip and a vacuum cleaner to suck it up as it comes loose.

 

The stuff that's really caked on, a Q Tip doesn't do much. I've used a toothbrush before but it doesn't get into the crevices. I even tried a chopstick...LOL. Need some better ideas