Bob_98SR5

Guys,

Ah, I hate annoying stuff like this. Today after meeting Steve (Robinhood) and Miki for lunch, the wife and I were driving back. We turned on the heater and we hear this faint, consistent ticking noise. It sounds like a plastic gear sound. We figured out it was a result of the heater being turned on b/c when we turned it off, the sound went away.

Anyone have or had a similar problem and fixed it?

Thanks,
Bob

Highland Runner

I had this type of problem and I'll tell you what it was. A mouse had made a nest in the fan unit. The fluff and stuff was inside the fan and little pieces were sticking through hitting the sides as it turned. I also had a Tacoma where leaves had made their way into the fan from the cowl. The twigs stuck through the fan making a clicking sound as it turned. This problem was intermittent until I fixed them. I guess the pieces sticking through broke off untill another piece stuck through. Some what of a pain to get the stuff out of mine. I could only somewhat see the fan. Used a vacuum with a little tube and a piece of coat hanger to pull the stuff out. Eventually the fan on full speed will blow the rest out.

Bob_98SR5

eeeek! a mouse! i'll have my wife do it.

one of the other odd things that i noticed today too is that when i try to move the lever to the left (recirc), it is much harder than before. there is some resistance.

i'm going to have to take this apart. well, i'm used to it so no big deal but i hope that its not one of those little plastic gears. you konw they won't sell such a little part and so you'll have to buy the whole million dollar unit.

bob

MTL_4runner

Bob, I'm afraid you will need to pull the blower motor but it will be obvious what is making the noise right away. It will also give you a chance to clean out the duct system as it is surprising how much dust and dirt gets in there.

Robinhood150

Maybe you should send in the cat!

MTL_4runner

A snake might work better.

Robinhood150

Oh I'll fit the cat in there.

Bob_98SR5

MTL,

Thanks, I'm going to check out my FSM tonight.

Patty was totally against the cat going in there and inspecting. Though a little catnip might persuade him.

Bob

Highland Runner

I forgot to tell you guys how I knew it was a mouse in the car. My brother and I got in to go to the store and he turns the heat on. As so as he did a piece of mouse ear comes out of the vent and lands on him. We didn't use the heat after that. The mouse was nowhere to be found when we took it apart though, just the nest.

Bob_98SR5

Guys,

I finally got off my lazy butt and inspected the fan as MTL suggested. Sure enough, he was right. All it was were some small leaves and a twig. Here's some pics:

Twig and leaves:


And yes Jamie, the thing was filthy! I took the time to take a scrub brush to it with some mild, soapy water. I was amazed at how much dirt was in between the fan blades and the HVAC ducts:



Here it is, all clean:



To remove the fan unit, you'll need to remove the glovebox. Al lthat takes is a screwdriver and a 10mm socket. you'll also need a #25 torx bit, a flexible drill shaft (an invaluable tool---you should run out and buy one of these asap), and of course, a powered drill. There are 3 bits underneat that need to be removed. Once it falls out, you need to unclip a black harness. of course, write up coming soon.

Thanks guys. And no, no little mouse was found.

Edit: writeup here at http://www.4runners.org/articles/fan
Bob

MTL_4runner

No prob man.....thanks for doing the writeup!

Fink

Will this technique also work pretty much the same for the 2nd gens? I have this same problem and was about to post something on it but then I found this thread...if it will work for a 2nd Gen then I'll be doin' this shortly.

Fink

MTL_4runner

I would bet it is very similar but the fan assembly may be quite different. Look in a Haynes manual to see what your duct system looks like and how to remove the blower motor. If that is not the problem, it will at least give you a chance to clean out the fan and the ductwork.

Fink

Alright...thanks for the advice MTL!

Fink

2001Millrunner

my heater makes ticking noise as well, i'll take it out and inspect it as well. thanks guys, i was wondering what that was. and it was getting very annoying

MTL_4runner

Any of you guys having any heating problems too?
Mine is not as hot now in the dead of winter.

Mossback74

Heater not hot anymore? tell it to go on a diet and hit the gym

well, lets see, check coolant level
full?
Is thermo stuck open?
no?
Is heater core clogged? (long shot)
no?
Am I out of ideas?
YES

MTL_4runner

Coolant is perfect and very clean (I flush it often)
Truck's engine shows good and hot (just under midway)
I am thinking heater core too.....maybe it is is just covered in dust/dirt/debris.

TDiddy

Great work Inspector Gadget! I've noticed that ticking on occasion too, and after seeing pics of that dirt, I'm gonna have to tear in to mine as well. Nice job with the write up!

MTL_4runner

Well I finally pulled out my blower motor and it was really not too bad as far as being dirty although when I put the clean one back in and turned it on full a whole bunch of dust blew out of the vents so there must be some increase in airflow to do that.

The blower was definately making some faint squeaking noise before and it is almost silent now so mission accomplished.

My experience was a bit different than Bob's because the screws holding the unit up to the ducts were 8mm instead of 10mm and to get it out I needed to remove the doorjam molding and the passenger side kickpanel (both very easy to do). After undoing the screws and the electrical connector, the unit just drops right down.

The other big revelation is that you can service the blower motor bearings too. The black plastic housing can be separated from the motor by undoing the 2 screws on the bottom of the motor as you can see in this pic here:



Then once those are out, you need to pry off the access cover. This is a little shield that is also on the back side of the motor (it just pops off with a screwdriver). Then you need to use a screwdriver to pry the motor out of the housing using the access hole for leverage. The motor should just slide out but it is a tight fit so take your time and don't apply too much pressure or you can crack the housing. Took me a little time but it came right out. Then when it is apart, you have access to the brushes (check them for wear) and oil the bushings. I used electric motor oil but marvel mystery oil or 3 in 1 oil will work fine too. The rear bushing has a pad for absorbing the oil so be sure to soak it thoroughly. The front bushing requires more disassembly to get at it (you need to remove the squirrel cage first). I did not go any further since it it is winter and we are screwed up here if I damage it, so I left it alone. I will disassemble it more this summer.

Another thing is that it is ok to fully submerge the blower assembly (including the motor) in soapy water or a cleaning solution (make sure to rinse with water after) as long as you let it dry thoroughly after. The motor runs on DC so technically it can even operate underwater.....no need to fear getting water in there, but again make sure to dry it out before install just to prevent rusting. You can also spay the inside of the motor with a little WD40 for some extra insurance against this.

It was definately worth doing so I hope this helps others.