Something...alive in my HVAC ducting

2000alhVW

Veteran Member
Joined
Aug 30, 2018
Location
Silver Spring, MD
TDI
2000 Golf
My 2000 Golf has become my daily driver. And I do drive it daily.
All has been calm.
But this evening, I was making my 200 mile trip back to school. To keep the cabin decently warm, I turn the temp dial 80% to hot, fan on 1, with re-circ off.
About 1 hour in, I hear an odd scratching noise. Just a quick one-time flick or scrape. Then I hear it again. Maybe a double motion this time.

"Wow I guess I have a couple leaves stuck in the cowl"

I hear it again maybe 2 minutes later. Hmmm...
I turn blower motor to 2 hoping to jostle the leaves loose.
I hear lots of motion.

Before, it had my curiosity, now it has my attention.

I turn blower to 4 with heat on 100%. This thing goes crazy. Several scratching/scraping noises, what seems like scurrying or frantic movement.

I turn it back down realizing that something may get chewed through in a primal panic. I would like to avoid that if possible.
Less heat, less movement.

I pull into a gas station, turn blower on 4, and squat in footwell with a flashlight. Nothin'
Hmm...
I finish my trip, and this thing is moving around a lot. Heat or no heat, there's scratching. Occasionally I heard weird noises, such as that electrical sound when a capacitor charges up. Kinda like the sound these MK4s make when the interior light timer expires and the lights dim out, or the sound a large camera flash makes.
I heard that noise twice, and thought it chewed through a relay or something. Additionally, there was a time I heard an odd whistle while pressing on the throttle.

I get to my destination and tear the dash apart as much as I can with no torx tools. I pulled off steering shaft cowl behind pedals, and removed fuse panel covers.
10 minutes looking with a flashlight, and I got nothing. No rodent eye contact. No droppings. Nothing chewed up. No collection of foam/carpet nesting. And I heard this thing like between my feet and the steering wheel.

Any ideas?
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
Sticky trap or mouse trap baited with peanut butter. Just set it on the passanger floor.
 

ColbyM

Member
Joined
Oct 24, 2017
Location
VancouverIsland
TDI
2000 Jetta & 2001 Golf
I'd take a look at your cabin air filter and the cabin air exhaust duct in the back. Had a similar problem and thats where I figured they got in. Totally chewed up


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2000alhVW

Veteran Member
Joined
Aug 30, 2018
Location
Silver Spring, MD
TDI
2000 Golf
Will definitely do more investigating.
It's a weird thing - on one hand, it can't possibly be anything other than a live animal.
On the other hand, I keep trying to tell myself it's just a really stubborn leaf or chunk of something.

I just find it odd that I somehow gained a mouse in my daily driven car parked in the suburbs.
Ironically, I picked up a semi-neglected project car, and pulled off the passenger door panel literally 2 days ago to find a HUGE mouse nest.
 

JB05

Top Post Dawg
Joined
Oct 20, 2005
Location
Il.USA
TDI
Golf,2005,anthracite blue
You might find a nest on the cabin filter. I had one a couple of years ago.
 

TdiRN

Veteran Member
Joined
Jul 7, 2015
Location
FL
TDI
2002 VW Jetta, 5 speed, 352k miles
I would pull the blower motor out and see what you can...
 

2000alhVW

Veteran Member
Joined
Aug 30, 2018
Location
Silver Spring, MD
TDI
2000 Golf
I checked my airbox. Nothing.
I pulled out cabin air filter and looked down, but could only see the hamster wheel of a blower motor. Nothing suspicious or odd.

I heard the scratching again backing out of a parking lot, but it's very inconsistent. I can only hear it when the car is moving, typically on the highway. I have not been able to reproduce the sound with the fan on with the car idling.

I guess I may try to pull the blower motor before I've got a dead rat stinking up my ducting...
 

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
My Uncle had a weasel get into the duct of his Honda Accord and it died in there. Never knew until one day the smell was suddenly unbearable. It's quite odd too because it was always garaged when not being driven and he a bit OCD about stuff.
You never know.
 

mk3

Veteran Member
Joined
Sep 13, 2005
Location
Wisconsin, USA
TDI
03 Jetta GLS 5-speed
I guess you need a new blower. The obvious question is whether you have ever heard the noise without the blower running.
 

bmw

Active member
Joined
Dec 23, 2018
Location
Ontario
TDI
Mk4 Jetta Wagon BEW
Definitely pull your blower motor and check, I see tons of mice get into cars here in Ontario, they like to eat the hood insulation and soy wire sheaths on newer cars. Knock on wood never had any in my own vehicles, however I've seen actual mice, dead or alive on atleast 15 customer cars. If they start to chew into your wiring thats where the real issues being lol. Hopefully for your sake it's just a leaf on your blower. Remove the glove box as this will allow you to see if it's maybe to the left inside the dashboard, you can sneak it out without removing the center console trim
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
I checked my airbox. Nothing.
I pulled out cabin air filter and looked down, but could only see the hamster wheel of a blower motor. Nothing suspicious or odd.

I heard the scratching again backing out of a parking lot, but it's very inconsistent. I can only hear it when the car is moving, typically on the highway. I have not been able to reproduce the sound with the fan on with the car idling.

I guess I may try to pull the blower motor before I've got a dead rat stinking up my ducting...
The turn signal/flasher will make a scratch like odd sound.
 
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