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Discussion Starter · #1 · (Edited)
Hello,

I keep getting a burning plastic smell when I run the heating or just the fan on the cool setting when driving. (The odor comes and goes, and is noticeable during cold temperatures or in the rain)

I've noticed I have a coolant leak, I recently topped up the coolant to make sure it isn't low, but what could be the reason for this burning plastic odor?
 

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If you have a coolant leak; i would have the cooling system pressure tested, to pinpoint the leak Nd repair it.

I use this pressure test kit; as it has the specific vw adapter for the coolant tank we need.

PITTSBURGH AUTOMOTIVE
Radiator Pressure Tester Kit



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Smells, that come through the hvac box; are pushed into thebinterior by the fan motor, can be tough to nail down.

Depending on the year of the beetle; rhe air comes though thr plenum and the cabin filter. All kinds if junk, debris, dirt, old leaves, pine needles and even the ovaasional dead animal shows up in these areas areas. The dash panels cB e removed; take a shop vac, suck out all the junk lying in there; change the cabin filter and with a rag, wipe everything out with hot water a bit of Clorox, to kill of any bacterial growth any bad smells. I clean out this area and replace the cabin filter once a year, usually in the spring, when a/c use fir the summer is approaching.

Also, there are regular cabin filters and those are infused with carbon and this purifies the incoming air air it does, make a difference!

I have a hard time finding the carbon filter type at my local auto parts stores; you can order them online or my local vw dealer, has them in stock.


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If you still have smells coming in:

Check the hvac box; be sure no plastic bags have been sucked into the blower fan and are causing the fan ti bind or the bearings in the fan, could be worn out, binding, getting hot and causing the burning smell.

Leaking heater core: the heater core maybe leaking and it resides in the bbac box and the blower fan, circulates the smell into the interior.

Oil leaks: oil leaks, like the valve cover; causes oil to get on the exhaust manifold and this creates a burning smell and the this smell, gets sucked i to the plenum and the blower fan circulates this into the interior. Fix the oil leaks and degrease, pressure wash, the engine and the residue should burn off. Take a short drive at highway speeds and the smell, should go away after a day or two. .

These are the common issues we see; check them out and hopefully, you will find the source of the annoying smell.


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Discussion Starter · #6 ·
Hi billymade,

Thank you for the info and the video, I will have a look and see if I can find where the odor is coming from.

If there is a coolant leak, should I have the system repressurized, would it solve the problem?
 

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The cooling system pressure test; is to help you find the coolant leak, which can be hard to pinpoint.

You may be able to find it without the pressure test but keep in mind, if you have to top off the coolant, there is typically a leak and should be repaired to fix it.

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Hello,

I keep getting a burning plastic smell when I run the heating or just the fan on the cool setting when driving. (The odor comes and goes, and is noticeable during cold temperatures or in the rain)

I've noticed I have a coolant leak, I recently topped up the coolant to make sure it isn't low, but what could be the reason for this burning plastic odor?
always turn the AC on to blow most of the heat away from the engine and avoid overheating the only time my beetle overheated I had turned the AC off

The most common leak for me is right where the coolant enters the engine check below if you can see a puddle or two and replace it. I sold my beetle but it’s a fantastic car
 

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Discussion Starter · #11 · (Edited)
Changed the cabin filter (Not as easy as it looks in the video!) after changing it, went for a test run:

1. After changing the filter, the air quality was amazing! When running the fan when the car is idle, no odors.

2. There is a bit of condensation on the front windshield, passenger side, when driving. I don't know why this is happening, but it wasn't like that before changing the cabin filter. It isn't too
much, but it's there.

3. When running the heating, there is a tinge of the plastic odor, but it isn't burning, it's more like
hot plastic, it disappears after a whlie.

4. I notice a tinge of odor, a combination of something like an old cloth and a tinge of vinegar, which only happens when I begin to drive the car, with the fan running, it disappears when driving.
(The old cabin filter had a similar odor when I removed it)

Changing the cabin filter is a good idea, highly recommend it.
 

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Discussion Starter · #13 ·
I noticed the new filter was somewhat darker than the original, but there was nothing on the package or filter to indicate the materials it was made out of. (This is a genuine VW filter) On the package, it said "filter element" and on the filter itself it said "MANN" filter.
 

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My local vw dealer: had the charcoal impregnated version, in bulk packaging at a affordable price. For some reason I had a hard time finding the same filter at typical auto parts stores; and some of the pricing they were charging; was really high, for some unknown reason?


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As to the turning station and add smells; I would have your cooling system pressure tested and see if it holds pressure and then confirmed coolant isn't leaking into the carpet area is the dash.


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Many electrical and melting issues; tend to emit, some pretty strong, noxious, smells, you could do a sniff test and see if you can find the source of the smell?

Otherwise as noted above, you could remove the HVAC controller with the knobs and see if it's melting like many have reported before.


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Discussion Starter · #17 ·
Many electrical and melting issues; tend to emit, some pretty strong, noxious, smells, you could do a sniff test and see if you can find the source of the smell?

Otherwise as noted above, you could remove the HVAC controller with the knobs and see if it's melting like many have reported before.


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If there's a problem behind the HVAC controller or the knobs, how can this be fixed? The thread wasn't clear on how to fix this.
 

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Some, have taken it apart and reattached, the broken part, on the selector; using a strong adhesive or something like JBWELD.


Its such a common problem, failure issue; that repair services are available online, Dorman fixed them or you can get another used one or buy a brand new unit.
 
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