Rough vibrating sound when heat is on

[idris]

Sometimes when I'm going at low RPMs (or whatever they're called in e-terms), I hear a very strong rumbling sound from the heater, almost like the fan is vibrating something at just the right resonance or is running up against some wires. If I turn off the heat, the sound goes away.

Has anyone else experienced this? Any thoughts on what it could be?

 

[preilly44]

I think I have this or something close to it. It seems to happen most often when I'm regen braking. I never had it happen before I took it in to a dealer to have something checked. Now it happens daily. I'm not sure what to do about it because I know the dealer knows nothing about this car.

 

[idris]

I just took my car to the dealer for this (and for the recall). They called me back and said the technician said that was the sound of regenerative breaking. I told them that's ridiculous because it only happens sometimes and only when the heat is on. Hopefully they'll figure it out, otherwise I have to talk to VW of America.

In general, I guess the problem with a new car and new class of car is the dealers and service people have no experience.

 

[svento]

I just took my car to the dealer for this (and for the recall).

Recall??? On the e-golf?

 

[idris]

Yeah I got a letter about some cable housing by the charger that makes the charger make a sound. I don't remember exactly... It's nothing serious.

 

[svento]

Oh interesting. I searched my VIN here (http://www.vw.com/web/vw/recall/) and it shows no recalls. Maybe yours has an older production date. Anyway, thanks.

 

[idris]

So, I demonstrated the noise to the dealer, they tried to convince me that's the normal sound of the generator. Then I showed them that's wrong because it turns off when the heat is off. Long story short, they said they fixed it (by putting some foam padding somewhere), and it's still happening

Will try again and see what happens

 

[preilly44]

I just had mine in for service for the same issue and they claimed it was from CD's in the glove box. I said that wasn't it and they said they checked for loose screws and panels and they didn't find any. As soon as I got in the car to drive it home I heard the sound. It's so frustrating the VW can't fix their own cars.

 

[rjnerd]

Most likely what you are hearing is the compressor in the heat pump. That the noise goes away when you shut the heat off is the main tell.

To heat the car, they essentially run the air conditioner in reverse. Think about how noisy your home AC compressor is. The one in a car is comparably noisy, but you can't hear it over the engine. (in an ICE car, they have the waste heat from the engine, so they only use the compressor to cool) A heat pump is much more efficient than a resistive heater, but they cost more and make noise.

If you want to see what a resistive heater is like, hit the "Max Defrost" button, and watch your range get cut in half. They run the heat pump (as an AC, not a heater) to dehumidify the air, and a resistive heater to reheat the air.

 

[preilly44]

I don't know a lot about the heating system but I would think if that were the case it would do it all the time and not just when I'm regen braking. Also, it doesn't happen all the time, only about 40% of the time.

Patrick

Most likely what you are hearing is the compressor in the heat pump. That the noise goes away when you shut the heat off is the main tell.

To heat the car, they essentially run the air conditioner in reverse. Think about how noisy your home AC compressor is. The one in a car is comparably noisy, but you can't hear it over the engine. (in an ICE car, they have the waste heat from the engine, so they only use the compressor to cool) A heat pump is much more efficient than a resistive heater, but they cost more and make noise.

If you want to see what a resistive heater is like, hit the "Max Defrost" button, and watch your range get cut in half. They run the heat pump (as an AC, not a heater) to dehumidify the air, and a resistive heater to reheat the air.

 

[idris]

Yeah, for me it's most likely when regen braking, but I even got it to happen when the car is stopped. It's definitely just something vibrating. I got it to happen while the technician was right there and he opened the hood and when he pressed down on certain areas, the noise would stop. When he let go, it would start again. I have been able to do the same thing since then.

@rjnerd, trust us this is not a normal sound that should be happening

@preilly44 (and others) please post here if you get it fixed!

I was thinking of calling VW of America to ask them.. they've been helpful in the past and seem to care if you have an unresolved issue. They also have no problem calling the dealers and making them do things for you.

 

[preilly44]

You should call VW NA. I have a case opened with them and if more people call in they might take the issue more seriously.

Patrick

 

[idris]

@preilly44 any luck in getting this resolved? VW of America left a message for me because I mentioned this in a review of my service appointment. I'm going to call them back, but It'd be nice to know if you got this resolved, and if so, how.

 

[preilly44]

Unfortunately, no it didn't get resolved. VW America was going to have a specialist who is in the area once a month look at the car but the day he was supposed to come we had 7" of snow and they canceled the appointment.

I'm scheduled for 4/11 now but I'm not sure they'll be able to hear the noise when it's that warm.

Please call and let them know others are having the issue as well.

 

[idris]

Alright, I'll call today and let them know. Also, my dealer has offered to trade-in my car for a new one, for adding $10/month to my lease. I'm going to see if between talking to them and VW of America, they can just give me a new one for the same lease price.

 

[mr23]

What area did you/he press on?
I imagine something like that large bogus 'engine' cover resonating with some vibration source...
Which could be the HP drive motor or the traction motor during regen as the source of the vibration. They should be able to adjust the frequency to avoid inducing that effect. They being a factory trained tech.

 

[idris]

The piece making the noise is some mounting bracket under the hood close to the inside of the car. I'm taking the car in on Monday and they're going to have a look along with someone from VW of America.

 

[preilly44]

Great, please keep us updated. Also, get specifics if you can...my service center is clueless about the E-golf and I'm probably going to have to walk them through the repair step by step.

They tried to tell me they heard the noise it and it was just CD's rattling in the glove box (which was not the case).

Thanks!

Patrick

The piece making the noise is some mounting bracket under the hood close to the inside of the car. I'm taking the car in on Monday and they're going to have a look along with someone from VW of America.

 

[preilly44]

Any updates on this? I'm taking my E-Golf in for service tomorrow because some idiot hit my car and broke the drivers side mirror off.

Thanks!
Patrick

 

[idris]

Yeah, so they took my car for a couple of days and a rep from VW of America came to the dealership to help them diagnose the problem. I wasn't in town so my brother picked up the car, so I'm not 100% sure what their solution was. I also am not sure if it's completely fixed because it's summer, so I'm not driving with the heat on.

If it helps, below is the info for my dealership. Maybe your service center can talk to them. Though, it's probably best if you do what I did and get VW of America involved. Then they'll see that it's a common(?) problem.

Darcars of Silver Spring
http://www.darcarsvw.com
(301) 622-7000