35,982 miles. Tapping/knocking in HVAC

[tdiatlast]

Out of warranty very soon. I have an intermittent sound, and I'm not sure I can duplicate it for the dealer. Here's the set-up:

While the car is gently warming up, from traffic light to traffic light, when I'm stopped for 10-20 seconds, I hear a gentle knocking (hollow, sounds like plastic) sound behind the glove box. It only happens after I've sat at idle for 10-20 seconds. The knocking is very rhythmic, 3 per second, about 13-15 knocks. Then it stops, and I don't (or can't) hear it when the car is in motion.

Fan is on 1, temp control position doesn't change it, airflow control turned to floor or dash vents.

I'll phone the dealer this morning (Saturday) and at least get my complaint "on the record", but I thought someone here might be able to point me in the right direction.

 

[tdiatlast]

I just spoke with the closest open dealer (Alexandria VA VW). The tech said this might be a ventilation flap motor going bad. He said it's not an uncommon problem.

He offered that they could, using a scan tool, "reset the paramters" of the flap motor. Does that make sense? I'm more inclined to insist on replacement of the motor.

 

[skinnyb]

Recirc motor is bad. Have had to replace 2 now on 2 different MKV vehicles I have had.


Sent from my iPhone using Tapatalk

 

[tdiatlast]

Dealership was open, so the tech did a scan, found no error codes. Problem was documented as a possible recirculation motor, and I'll take it in next week for replacement. They seemed very serious about the mileage (35,995 when I drove up), made it sound like they wouldn't have covered it without proper documentation.

Tech told me these motors sometimes begin to make noise, but claimed he never saw a "functionality" issue, had never seen a motor actually fail, even when the part was making a lot of noise. He said most drivers don't even hear the knocking/tapping.

 

[1998993C2S]

Edit text: The tech said this might be a ventilation flap motor going bad. He said it's not an uncommon problem.

He offered that they could, using a scan tool, "reset the paramters" of the flap motor. Does that make sense? I'm more inclined to insist on replacement of the motor.

Our MY06.5 with dual Climatronic HVAC has a similair flap noise which is effected (noise often minimised) by a "scan" when using the VCDS (Vagcom). 5k or so miles later the flap noise comes back; I've been practicing this "scan" strategy for over 40K miles. Recently though a 2nd flap (drivers side) has started to speak up.... The plan is to replace all of the frail plastic rack and pinion style flaps at once. Lemme guess there's not an improved flap component.... VW/AG or the OEM most likely haven't addressed the known defect/weakness. - From a numbers $$ perspective its understandable....

It's a cow path to push these cost's elsewhere.....Both the client, that's VW, and the OEM know the threshold of defect responciblity is the warranty term. In 2006 the VW new car warranty was 4yrs/50k miles... Currently the same warranty is 3yrs/36k miles? ...that's a huge $$ reduction to VW. Let's face it,,, the arguement can be made to the retailer/dealerships that if they do a better job with Customer Care in the initial year of new car ownership,,, that same owner will look to the dealership to repair the very same car at a high profit margin (dealership).... so why should VW AG (get in the way) by funding that extra warranty year/mileage. Way back when,,, ... what did VW AG get for their 4th year warranty money?? VW reducing the warranty term potentially gave the dealership a raise $$ and certainly reduced their (VW AGs) per cost/units sold ... I'm just saying.

Where were we?? Oh I was saying my flap makes noise at times....

 

[tdiatlast]

Hmmm...noise "minimised" with VagCom...maybe yet another reason to invest in one, or to befriend a No VA club member that's willing to share (yes, malooshek was great and very kind to me, but he's a bit far!)

I assume they'll be replacing "like-with-like".

I'm curious, though. Do those of you with many more years/miles on your car have this same noise, or is it totatlly random?

 

[robbinsresort]

Mine's been doing that for over a year now. Happens more often in the winter time. Heating/cooling seem to be unaffected. I'm not that concerned about it.

 

[narongc73]

I hear the same thing but from under the steering wheel.

 

[Marinel]

I guess I'm not crazy... Ive been hearing the same thing occasionally. Everything is working as it should so I never thought much of it.

 

[PaxTDI]

It's the recirculation motor. Mind made this noise for over a year. From there it went to a steady racket when the car started up which means the until failed. I replaced mine myself two weeks ago. See post.

 

[tdiatlast]

Please clarify "see post". I searched, found nothing. Thanks.

 

[PaxTDI]

Please clarify "see post". I searched, found nothing. Thanks.

http://forums.tdiclub.com/showthread.php?t=304490&highlight=recirculation+motor

 

[tdiatlast]

"Recirculation motor"...exactly what does it control?

I've noticed on my JSW, air control on the floor setting, fan on 4, very little to no air comes out of the rear under-seat floor vents. Also, the fan motor on 4 makes a drumming sound (very slight), similar to my 87 Audi 4000S. (I was told at the time it was "normal", distortion of the plastic squirrel-cage fan...it lasted for 19 years, 192k miles). My wife's sedan blows a lot of air on the rear floor, and the fan doesn't "drum".

FYI, the resistor pack (?), controlling speeds 1-3, was replaced on the JSW around 20k miles. (I read here that a failing fan assembly might cause the resistors to go bad...is my fan going out?)

Is all this related?

 

[troutbum1971]

I just spoke with the closest open dealer (Alexandria VA VW). The tech said this might be a ventilation flap motor going bad. He said it's not an uncommon problem.

He offered that they could, using a scan tool, "reset the paramters" of the flap motor. Does that make sense? I'm more inclined to insist on replacement of the motor.

check with springfield VW too.... i've used them, and they are very good and friendly..... not crooks either

 

[BMac]

Mine has been doing it for quite some time (~ 2yrs). I have noticed that it is a bit worse this winter but apparently not as bad as it get. #-5 popping sounds once the engine warms up (if it warms up these days). The other day I drove (traffic) for 45 minutes and the temp.gauge was 1/2 way tooperating temp.(90 degrees C).

BMac

 

[BMac]

Forgot to mention that mine was on the drives side - near my left foot area.

BMac

 

[dano0726]

I wonder if my (2006 Jetta: 53K miles) recirculating motor is out -- I can't get any directional air flow through either my windshield via the defroster setting or the floor via the heater setting. I can get hot or cold (the A/C works) air to blow through the dashboard vents. I've checked the HVAC control module and the spring linkage (it was connected and moved when I changed the knob on the control module).

 

[Jnitrofish]

For those of you that have the dual climate zone system and hear knocking more in the colder months, it's the temperature blend door actuators. They are trying to push the door all the way to heat and beyond, and once the door has hit its stop they continue to push and cycle on and off, making a knocking noise.

I played around with VCDS one night when it was in the 30's and could see it in the HVAC measuring blocks for the temperature blend door position potentiometers (as soon as it went to full heat it started knocking). And you can actually see the drivers-side actuator and arm from the drivers floor well behind the hot pipes bringing in coolant to the heater core.

I live with it.