My 7 y.o. daughter thinks it sounds like a trapped squirrel scratching to get out. I'm humoring her, but I would really like to get it figured out. Here is an attempt at a description of the sound.

There is an intermittent sound, sort of like a flapping or scratching which seems to come from the engine compartment. In the area of the right side, behind the glove box sort of. My wife claims she has heard it when driving AND when she was parking. I have only heard it when traveling at 30 to 45 mph. It's a brief, 2 - 3 second sound and can not be reproduced on purpose. First time I heard it I thought it was water from the road being sprayed just right off the right front tire. It has happened since then when not driving through puddles so I don't think it is that. It is a new sound anyway and I have had the truck (see sig.) since new. It's not related to braking or engine rpm. Really sounds to me like something non metalic is loose but I can not find anything. I looked at the fan because my son said it sounded sort of like a baseball card in the spokes of his bike. I don't see anything plastic loose near there that could at times get dinged by the fan.

I have looked under the hood for anything obvious or loose, (and squirrels) and can't find anything.

Any ideas?

 

Could be the fan motor maybe. Does it happen with the fan off? If not you may be able to get it to happen by tapping on the blower motor. Just a guess but worth a shot maybe.

 

I had the same sound, only it wasn't intermittant. I was sure it was the blower for the heater going out and I was all ready to buy the part and fix it, but it just went away on it's own and I haven't heard it in about 3 weeks.

 

Well I have heard it a couple more times and can not figure it out. It def. is not the blower for the heater, as I thought the same thing at first and eliminated that possibility.

 

this may sound silly but could it be a piece of paper or something that fell through the defrost vents?

 

Looked for that sort of thing and found nothing. It def. seems to come from the other side of the firewall. Heater/Defroster blower setting does not affect when it happens or cause it to happen. Seems to be random.

 

I've got a noise in that same area (a little higher maybe) that sounds like a pig grunting. On mine its the windsheild wiper pivot joint on the right side. Are you running your A/C when it happens? My truck has a very loud expansion valve and it make all kinds of noises.

 

>I've got a noise in that same area (a little higher maybe)
>that sounds like a pig grunting. On mine its the windsheild
>wiper pivot joint on the right side. Are you running your
>A/C when it happens? My truck has a very loud expansion
>valve and it make all kinds of noises.

Squirrels, now Pigs!

It does not seem to relate to the heater a/c system, but I still have not figured it out. I guess I will have to climb down out of my 2001 and drive the 89 for a few days and really concentrate on the noise.

 

[updated:LAST EDITED ON 18-Nov-02 AT 01:32 PM (EST)]I spent some time this weekend trying to locate the sound. Could not hear it outside, under the hood, or under the truck. It def seemed to be coming from where, (even with my limited mechanical knowledge), the only thing there was the heater core. It did not sound like water, but I checked the system anyway. Found a defective radiator cap,(wasn't seating properly anymore). Maybe it was sucking air into the system? Anyway, changed the cap and added water/antifreeze. Even though the resv. was ok, it took about 1 gallon when added through the radiator! I'm guessing the resv. is only an overflow? I've only driven a few miles, but so far the noise has not returned.

 

That's interesting. Check your oil to make sure there's no water in it. As you know a leaky head gasket can pressurize your raditor and blow the water out through the radiator overflow.

I guess we should have asked you what type of squirrel sounds. Is the mating squirrel sound, where the buck is sending out a challenge to the other squirrels? or the high pitched "the hawk has me" squirrel sound?