Mitsubishi Rainstick

Rainsticks - Sound of the RAIN in one instrument
Workshop Medieval

A couple of weeks ago we started hearing this rainstick noise coming from under right hand side of the dashboard whenever we made a left hand turn. There is a known problem with one of the flaps inside the heater duct, and I figured it had broken loose and whenever we turned a corner, it would flop over and rub against the fan. But it sure sounded like running water. There was no leak inside the car, so it was baffling.

Blower with motor cooling duct popped open

Finally decided to take the glove box out yesterday to see if I could locate the problem. Along the way I found that the blower is easily accessible from the passenger footwell. Seemed to be a little wetness there, and when I popped open the hatch on the blower's cooling ducts I found signs of rust. So there's been water in here.

A little Googling turns up a likely culprit: the drain hole for the air conditioning evaporator. (That's the small radiator that sits inside the ductwork inside the passenger compartment. It doesn't really radiate anything, it's more of an anti-radiator.) Okay, that's enough for today, I'll finish this tomorrow.

This morning I've got an appointment first thing and at the first corner I turn, a pint of water comes out of the hole where the blower was and dumps in the passenger footwell. More water comes out every time I turn left. The water had stopped coming out by the time I got home.

I tried locating the drain hole yesterday, but I'm too thick to slide under the car, and the driver's side was too close to the wall to allow easy access, so today I moved the car to the center of the garage and drove up on a couple of wood blocks.

Looking straight up from the ground. Firewall at the top, engine bay at the bottom. A/C drain hole is small, rusty slot in the upper left, just below the black smudge marks.

Now I can slide underneath and I am able to locate the drain hole. It's not very big, maybe a sixteenth of an inch by about half an inch. I stick a thin metal stick up there and root around. The stick can go in an inch or two before it runs into a solid barrier. Nothing comes out, but it seems like it might be little clearer.

Now I can put the blower back in. It was no problem getting it out, a Torx T-25 screwdriver worked just fine, but now I'm trying to put it back and things aren't going well. One of the things I've heard about Torx is that they aren't too particular about size. A driver for one size should work with screws that are a little bigger or a little smaller. Didn't work in this case. The T-25 had a hard time staying engaged. The T-15 worked until I started to apply some torque and then it slipped. Fine. The screws are also slotted, so with a straight bladed screwdriver I was able to get them tight.

I probably have a T-20 bit somewhere, but looking for it is an iffy proposition. It might be here, in which case I should be able to find it, but it might be on the moon in which case looking for it will be a waste of time. And looking for it means climbing up and down the stairs to the basement and I'm already feeling the strain of this operation. I pressed on with what I had.

The insulation on the underdash sound barrier and the passenger floor mat were pretty well soaked, so they are drying in the sun. It's kind of cool today, so it may be a while before we find out if I actually fixed the problem.

This wasn't a big project. There are six screws holding the underdash panel and just three holding the blower, but they were under the dash, so I'm down on my knees with my head and arms stuck in the footwell trying to turn screws, screws that I can just barely see. It's awkward in the extreme. An electric screwdriver might have come in handy, if it was small enough to get in there. Plus I would have needed the correct Torx bit (see above). Anyway, it was exhausting. On the plus side I got a good nap and now I feel like I've put in a hard days work.