Fresh air inlet clogging with debris

Fresh air inlet clogging with debris

As many know I am looking for root causes of unusual odors in the cabin. As a heads up I found that it is easy for debris to build up on a screen, not easily seen, deep inside the fresh air intake. To see this and clean it out you must remove the plastic "grill" cover found in the frunk. Here are a few shots (none show the "grille" in place since you can see it for yourself when you open the frunk). I recommend you check this area out and vacuum the debris out if you see any. Debris will restrict airflow and organic debris will rot and create odor. You will note there are a couple of "levels" in the duct where debris can build up (the redwood leaves shown in one pic are not the same ones shown in the pic deep inside the duct).

I took a few pics and when I put a camera deep in the air intake "duct" I found stuff:

jd4714 | 18 augusti 2019

Good to know, thanks for sharing.

M3phan | 18 augusti 2019

Digging in there tomorrow morning! Thx.

gmr6415 | 18 augusti 2019

@Magic 8 Ball, considering the location of the drain and the lack of a tube this may be the answer.

My neighbor is an HVAC guy and swears by these things for keeping HVAC drain pans and tubing clean and odor free. These are "computer room safe" so they are safe around electronics. There would have to be a way to get a tablet into the evaporator drain pan. I don't know if that can be accessed once the filters are removed.

Magic 8 Ball | 18 augusti 2019

@gmr6415 I am still focusing on first principles design issue since this is not happening as quickly, or ever, in other cars. Preference would be to not have to use methods you would not normally have to use on other cars. I was surprised to see the debris deep in the intake duct and just a few rotting insects can stink up a storm. The issue does not seem to be affecting everyone and really don’t have data if it is common or rare. I love solving mysteries and it bond me out when people push back with “over the top” when no one actually knows root cause.

Magic 8 Ball | 18 augusti 2019

Bond me out = bums me out

gmr6415 | 18 augusti 2019

@Magic 8 Ball, I understand completely. When I was working on heavy equipment I would sometimes wake up in the middle of the night with a fix for an issue I had been working on, sometimes weeks or months.

I'm assuming you've seen this video and how much junk he found in his cabin air filters. At first he thought they looked pretty clean until he tapped them out.

From what I'm finding the 3 doesn't have the same quality air filters as the S and X...not HEPA rated. I did find an aftermarket filter that is HEPA rated and contains activated charcoal to remove odors...pricy though for the pair.

Magic 8 Ball | 18 augusti 2019

@gmr6415 I did see that video (it appears to be the one where he could not find the filter). He made another video, I think, where he thanks someone for showing where they are unless he added to the original video.

When we ordered our 3 they invited us in to drive an S (an attempt to try and flip us to a more expensive car) and the associate told us the main difference in length between the two cars is the space the Hepa filtration units takes. Taken with a grain of salt, of course.

That is an excellent find of aftermarket 3 filters (I had been looking since there are several choices for the S now). Thanks.

gmr6415 | 18 augusti 2019

@Magic 8 Ball, Sorry I meant this video. where he addresses the smell and removes his filters.

Magic 8 Ball | 18 augusti 2019

@gmr6415 He appears to be on to a similar chase I am now on when he mentions restricted airflow. I do not approve of using the fogger as a temporary fix.

A trick often used in A/C units, to pull additional moisture out of the air and to make things even colder, is to slow down the fan. Slowing airflow over the evaporator lets the evaporator get even colder causing increased condensation on the evaporator. Dirty filters and restricted inlet (with debris) will certainly cause reduced airflow.

I am thinking an aftermarket filter that is less restrictive may just be the ticket necessary to keep airflow high enough to blow the evaporator dry. It also makes me think an evaporator in a horizontal position vs vertical would aid in draining condensate built up between the "vanes" in the evaporator. (nothing we can do about that).

With restricted filters and inlet the fan can run loud and make it sound like it is moving air but it really is not. The key, IMO, is to keep lots of air flowing past the evaporator when in use.

gmr6415 | 18 augusti 2019

Do you have access to a manometer? Some of them are sensitive enough to check very low differences in pressures.

I know all about restrictions in HVAC. As I mentioned my neighbor is an HVAC guy. About 10 years ago he helped me replace my unit. It was a higher seer rating than the old unit. It produced so much condensate because of lack of appropriate airflow in the duct work that the 3/4" drain couldn't keep up with it. The air handler sits above our dryer in our garage. Condensate was spilling out the seams around the access door for the evaporator unit. The drain wasn't obstructed. It just couldn't keep up.

I made a plexiglass cover for the air handler, so we could watch it in action, and it was remarkable the amount of condensate it was producing. It looked like someone had stuck a garden hose in there and turned it on. (If you don't remember this is Central FL)

Get this, he went and spoke with the supplier who sold him the unit and when he told him what was happening the guy responded, "Is the air handler mounted in the garage and the garage door faces west?" My neighbor said, "exactly." The supplier told him to remove the unit and bring it back because it won't work properly under those circumstances.

I understand that having the air handler in a non-conditioned space is going to result in more condensate, but what the heck does being in a garage with a west facing door have to do with it? Anyway the guy gave us a different unit made by a different manufacturer. It did work better, but I spent a week in our attic with a manometer re-doing ducts until I got the correct pressure differential between the inlet and outlet sides of the air handler. If I remember correctly I was taking a negative (vacuum) reading on the inlet side of the air handler and a positive reading on the outlet side and adding them together until I got within a given range with the combined readings. I was using a manometer along the length of the ductwork in the attic to find restrictions and eliminate them until the combined readings at the air handler were within range.

I agree with the air movement and restricted conditions. Most people don't understand that a fan will speed up under restriction, yet move less air. They will also draw a lot more current and can overheat from both conditions. In some cases you can burn up a compressor because all of the freon temperatures on the high and low pressure sides are off. It gets complicated.

Magic 8 Ball | 18 augusti 2019

In my career I designed many things including metrology equipment that required me to design Hepa and conditioned air environmental enclosures. Most airflow measurements were done with hot wire anemometers that had small probes that fit in small spaces. I do not have easy access to the labs and equipment anymore. I always use KISS as my design philosophy and I am thinking of designing a aftermarket filter that is less restrictive. Hepa would be more restrictive (assuming similar surface area) and would exacerbate the issue, IMO.

kaffine | 18 augusti 2019

gmr6415 said
I agree with the air movement and restricted conditions. Most people don't understand that a fan will speed up under restriction, yet move less air. They will also draw a lot more current and can overheat from both conditions. In some cases you can burn up a compressor because all of the freon temperatures on the high and low pressure sides are off. It gets complicated.

Fans draw less current when they move less air (even if pushing against more pressure). The reason they overheat when moving less air is the airflow is what cools them so no air flow no cooling.

wasabi5858 | 18 augusti 2019

I've been thinkning getting some cover like below and possibly put a air purifier's prefilter (not for HEPA, but bug etc) sandwiched between it and the factory vent but not sure if this air intake is use for anything beside interior cabin so a bit hesitant

gmr6415 | 19 augusti 2019

@kaffine, if you restrict the inlet side of a fan they speed up because of cavitation and a lack of available air to move, but they draw more current. Put an amp meter on the positive side and you will see. The two conditions combined, moving less air and higher current draw can over heat the fan motor.

gmr6415 | 19 augusti 2019

@@kaffine, I should have left that comment out, because I was thinking of the exact point of cavitation, which I didn't state. There are too many variables depending on type of fan be it designed for air flow or designed to be a high pressure fan and whether it's working in a closed circuit or an open circuit.

At the exact point of cavitation the fan speeds up because it's turning in a partial vacuum, but that partial vacuum is created by the fan itself, so there is a cyclical loading and unloading of the fan at that point. During the loading part of the cycle the amperage draw will go up. During the unloading part of the cycle the amperage draw will go down.

gmr6415 | 19 augusti 2019

@Magic 8 Ball, "I am thinking of designing a aftermarket filter that is less restrictive."

I agree HEPA would be more restrictive, and I wonder about the HEPA replacement filters on Amazon being too restrictive for a system that wasn't designed for it.

Because of the issues we had with our home HVAC system it was recommended that we went with custom built air filters for the return air side. They aren't at the return side of the air handler. That filter that's housed there is left out in the way our system is now set up. The are remotely mounted in the ceilings of various rooms throughout the house. That being said, the fact we use multiple return air filters instead of using a single filter in the air handler reduces restriction too.

Below I have included a link to some images of the replaceable material that the local filtration specialist came up with. It's very high flow with little restriction, yet it filters well. You can see that in one of the images of a dirty one where the white side of the material has turned gray/brown. That one has been in use for about 6 months and needs changing. They are two sided. The white side goes toward fresh air. The blue side goes toward the air handler inlet side.

I don't know what the material is, but the place that builds them locally and supplies the material is:

They don't appear to have a web site. We've been using these filters for a good 10 years now and they work very well, yet have very little restriction and that was validated when we were doing all of the pressure tests on our duct work. They custom build the frame to fit any size. Since I haven't seen the size, particularly the thickness of the M3 cabin air filters, I don't know if that would be doable. This material is an 1" think, but it's compressed into a 3/4" thick frame. I don't know if it's available in different thicknesses. I believe the material can also be ordered with Microban antimicrobial added. I'm not sure of that, but I remember it being discussed.

Here is the album link:

If for some reason that link doesn't work here are the individual image links:

Magic 8 Ball | 19 augusti 2019

@wasabi5858 I like the grille cover although I would want to know if it is restrictive to the airflow. Any additional restrictions, such as auxiliary filters will most likely create more restriction to the airflow, not a good thing, IMO. My theory is that the current filters are getting dirty quicker than thought and restricting flow so the evaporator does not get blown dry. The description says it is for the air conditioning inlet so, maybe, but good point on if it is used for more than that (I doubt it). What would be neat is if there was some sort of ionizer or UV "purifier" but, IMO, it is mostly about airflow and getting the evaporator to dry out.

gmr6415 | 19 augusti 2019

@Magic 8 Ball. This looks like the same material and may be the people you should talk to.

Magic 8 Ball | 19 augusti 2019

@gmr6415 Back in the day my daily driver was a 1951 Ford Panel truck that I restored (Parents of girls I dated must have hated to see me pick up their daughters in that one). It had a cowl vent that you manually opened with a lever. It was an air scoop that opened up to let air get scooped into the cabin. The only "filter" was large mesh screen door type mesh so bugs would not get in. I like the materials you show in the pics and was thinking similar. It should not be much of an issue to come up with a simple frame(s) and try different things.

gmr6415 | 19 augusti 2019

@Magic 8 Ball, I went ahead and removed my filters. They are 1 1/4" thick, so as you state making a frame wouldn't be a problem. HDPE (High-density polyethylene) is pretty easy to weld with the right equipment. I think it can be purchased as channel, so making a frame would be very easy.

A few tips on getting to the filters. Removing the side panel of the console was much easier starting at the bottom. I used a screw driver bent in a 90˚ angle and pushed up behind it to get it started

Some of the clips stayed with the console and didn't come out with the panel. Those fall out very easily. I lost one that even with a small vacuum hose I couldn't retrieve. When you go back in all of those clips need to be on the panel you are reinstalling not in the console, or again they fall out as you are trying to install the panel. That's how I lost one clip.

The top Torx screw on the cover over the filters is easier with a flexible extension about 4" long. Removing the wire from the speaker under the panel removed from under the glove box was a little tricky too. The wiring on the light was fairly easy.

I found a lot of dirt. I'm about 6 days short of having my car for a year and about 17,500 miles. Below are some pictures.

This is what fell out on the floorboard after removing the filters:
Dirt in the filters:
Dirt in the filters 2:
Dirt that tapped out of the filters just by dropping them on a clean hard surface. The bottom filter had a lot more dirt in it than the upper filter:
Dirt the was removed from the bottom of the filter housing. I made a 1/2" ID tubing adapter for my vacuum cleaner and sucked the debris out of the filter housing using a new bag in the vacuum. I then cut the bag open and the photo is of what fell out:

The filters didn't feel wet and there was no foul oder up in the filter housing, but I'm not having odor issues anyway.

gmr6415 | 19 augusti 2019

@Magic 8 Ball, it would be very easy to test. A small box that an OEM filter would slide into one end with a fan pulling air through it and a vacuum gauge attached would tell you all you need to know by comparing various materials to an OEM filter.

I don't think you would need to know the rated CFM of the fan in the car and try to duplicate that exactly to get a reasonable idea of what materials have less restriction than the OEM filter.

Magic 8 Ball | 19 augusti 2019

@gmr6415 Good find. I think the key is preventative maintenance, like you have done, to keep the airflow as high as possible. IMO this will be maintenance item that needs to be done much more frequently than "two years" for many and more so for those of us that park under trees etc. I would not expect the filters to be wet since they should be upstream from the edge of wetness (Carson fans will appreciate what I did there). It sucks they require a something like a torx with flex extension to access, they could have made filter access so much easier. I am definitely going with a custom design less restrictive filter. Many don't realize that filters become better at filtering when they get some dirt in them with the tradeoff they restrict flow when it happens. I think I can much better filter life using the materials you have already pointed out.

It looks like OEM filters are on Amazon now but not shipping until end of Sept. early Oct.

Thanks vlinev for providing link in other thread.

sheldon.mike1010 | 19 augusti 2019

This is an xlnt thread! Just checked my intake and found some leaves and cleaned it up. Thanks for info.

gmr6415 | 19 augusti 2019

@Magic 8 Ball, "IMO this will be maintenance item that needs to be done much more frequently than "two years"

Someone needs to become a console side panel clip supplier. Tesla part number 1067403-00-A

cmh95628 | 19 augusti 2019

Don't agree with the install instructions on for the EOM filters linked above and here:

Those instructions talk about installing via the glove box.

Thrillion | 19 augusti 2019

Filters only restrict at high flow cases.
This is the old K&N air filter argument that has gone around the ICE community for years.
Restriction only happens with a clogged filter during normal use.
If you run the fan at speed 10 for 99% of the time you could see some minor improvement with a less restrictive filter.
Its an exponential relationship, not linear. I'm in instrumentation and any flow restriction will be problematic at the high flow rates not normal cases.

tbd2001_01 | 19 augusti 2019
Thrillion | 19 augusti 2019

@tbd2001_01 nice.
Made mine for pennies with a cut-to-fit AC filter.
Those fiber filters can also act as a demister pad

Magic 8 Ball | 19 augusti 2019

If a filter design is such that the available surface area only allows for full flow when clean it most certainly restricts flow, even in low flow cases, when dirty. It is absolutely wrong to suggest otherwise.

The only case where the above is true is if the filter used has enough surface area to account for dirt impeding flow. Proper filter/fan/duct design, and application, accounts for this. It is bogus to generalize this because many fans, even many "proper" squirrel cage fans, do not support any or adequate pressure head.

Magic 8 Ball | 19 augusti 2019

The theory here is the evaporator and plenum are not drying out like they do in other cars and allowing for petri dish like conditions. @nailsmails do you have another theory why some are reporting this condition on less than 1 year old model 3 cars?

Thrillion | 19 augusti 2019

You misunderstood my point.

I stated "Restriction only happens with a clogged filter during normal use."
My point was that a less restrictive air filter only benefits at the high flow rates not when the fan is blowing at say 4 or 5. The pressure drop in relation to the flow rate is an exponential relationship and is based on the maximum DP allowed by the system.
Was not arguing that a dirty filter restricts more than a clean one. I was arguing that an aftermarket filter isnt going to increase flow at the lower speeds.
The bottleneck is the blower and rightly so, thats what fan speed is for.

Thrillion | 19 augusti 2019

Yes As I've said in other threads, I do have a theory and I believe there is a condition or a scenario that is soiling the filters.
Either by condensation or by rain water. Soiled filters can harbor the mold.
The Tesla mobile tech did everything but change the filters and the sell came back.
I propose replacing or cleaning the filters and the coil to rid the HVAC of the smell.

Magic 8 Ball | 19 augusti 2019

You have no information to support that unless you know the design parameters and specifications of the actual Tesla design and components used in the design. If the fan cannot support a pressure head any restriction, be it ever so small, will restrict flow at all speeds. I have extensive design experience with fans starting with muffin fans used in computers all the way to high pressure squirrel cage fans sucking air through a Hepa Filter. Tesla's first stab at this is to replace filters when the problem is reported and for good reason.

Magic 8 Ball | 19 augusti 2019

Your theory of soaked filters supporting growth is sound but If you have been reading, watching, and learning there are videos and reports from folks reporting stinky smell and removing dirty dusty filters that have no odor to them which disputes your theory in their cases. As I have mentioned, many times, there are many variables and probably several different root causes and different smells caused by each. Others have reported killing the mildew on the evaporator and reusing the old filters with smell being gone.

Thrillion | 19 augusti 2019

I don't have to know the design parameters of the duct system.
This is physics. There are many books about it.
I'd recommend the following:
Flow Measurement Engineering Handbook Third Edition by Richard Miller.
Miller literally wrote the book on DP flow calculations.

Thrillion | 19 augusti 2019

I baked my filters at 200 degrees and reinstalled.
They were not clogged as far as I could tell but they did look soiled, specifically one on the bottom.

Magic 8 Ball | 19 augusti 2019

Books are worthless unless you comprehend the material in them. My reference material among others:

Engineering Fluid Mechanics Roberson/Crowe
Cooling Techniques for Electronic Equipment Dave S. Steinberg

I understand the physics completely, it appears you do not. Every bend, turn, etc. results in loss of pressure head and many fans do not support a pressure head. If you want to push air through a system the fan must support an adequate pressure head. Without the knowledge of the actual system design Tesla uses throwing knowledge reference material you are familiar with is meaningless.

Thrillion | 19 augusti 2019

I want to apologies, to each his own. If some of the owners want to try aftermarket filters to see if they help, by all means.
I would like to share some knowledge that might persuade someone against purchasing something that may not solve the problem.
Normally I would suggest that the manufacturer has done the proper engineering and to trust their design but this doesn't seam to be the case.

Thrillion | 19 augusti 2019

And apologize for my spelling.

Magic 8 Ball | 19 augusti 2019

At least we agree the design does not appear to be adequate to prevent stinky smell on cars that are less than 1 year old. I suspect a novice engineer designed without thinking about reduced airflow when filters get dirty. I suspect that it happens at different times for different people because some get dirty filters earlier than others.

One of my working theories is brand new cars have adequate airflow through clean filters and it is not until airflow becomes restricted that there is not enough flow to dry the evaporator out. The restriction can happen anywhere in the HVAC circuit and I already found debris at the main inlet that would reduce flow. In your case (evidence of wet/soiled filters it is possible water made its way down the inlet to soak the filters (this is one reason they tell you to avoid high pressure sprays in car washes). Water can make its way down using blow drying as well. Water does not appear to be getting to filters under normal use.

Did you watch the video from Brian who pulls out dirty, non smelly filters, but he has stink in the car?

gmr6415 | 19 augusti 2019

@Magic 8 Ball, I ordered a new set of filters so I can play around with them. I've found a very thin layer of activated charcoal impregnated filter media I'm going to try to add. I think it will fit, and it doesn't look restrictive. I don't think that's a fix by any means. It's treating or prophylactically preventing a symptom rather than fixing the cause but seems a more long term remedy than just spraying some evaporator cleaner in and changing the filters.

I did have some after thoughts though on our earlier discussion. A good bit of the stuff in my filters was bugs or parts thereof and plant material. The pleated filter did a good job of hanging on to those bigger pieces; although, some of them were in the bottom of the filter housing, but those could have dislodged from the filter as I was removing it.

A pleated filter media at least doubles surface area reducing restriction as compared to using the same media without the pleats in the same sized filter frame. A surface without pleats like the stuff we are using in our house (noted above) isn't going to hold onto the bigger debris. It's all going to end up in the bottom of the filter housing. Since I couldn't see in there I don't know if that would end up plugging the drain or not. If someone has a scope with a light that they could look around with it might answer that question. My wife is a veterinarian I might ask her to bring a scope home since the tips are replaceable for sanitary reasons. I may be able to get ahold of one with a video camera attached.

Just an FYI and maybe should be a separate topic, but I wasn't aware that Tesla now has a "parts" option when you call. For me it was option #5. They requested I leave a VIN, Name and contact number, preferred SC and what parts I was looking for. I requested the set of filters and (6) of the console side panel clips I gave the part number for above...1067403-00-A

Within about an hour I received a PDF to digitally sign agreeing to payment and picking up the parts at my preferred SC.

I had never heard of this before. It was very easy, and I didn't have to hold the line for someone from the SC as happened a few months ago when I requested wiper blades...very nice option and service.

Thrillion | 19 augusti 2019

I'm a fan of i1Tesla and hoped he would have provided a solution.
The filters "did not smell" when he took them out and he commented that they didn't look dirty.
He later said that they could be dirty and blew them out.
He also did a white glove test on the coil (evaporator) and didnt find any dirt or residue.
This lead me to think that the filters only smell when wet. When dry, the materials in the filters absorb the smell.
I did not wet my filters to see if they would smell.

Magic 8 Ball | 19 augusti 2019

@nailsmails You did not watch the whole video, he most certainly did show the filters were filthy and showed the filth by a simple tapping of the filters. His filters did not show any signs of being wet. Wet filters always show witness marks of where water wicked up to and or dryed out from being wet

Magic 8 Ball | 19 augusti 2019

@gmr6415 It is interesting to see how large the condensate drain is and reports from Frank that he feels air blowing out from it. Many drains like this would have a duckbill valve at the end allowing liquids to drain out but remain closed resulting from low pressure air (it is a waste to blow that much A/C into the outside environment). We live if a world where even the best engineers create space shuttles that burn up and make simple math mistakes crippling billion dollar satellites.

alexatkinson903 | 18 februari 2020

Somebody wrote it's ok to use filters from a purifier.
I've found some purifiers with mixed coal filters for mold and so on.
I think, if it works, it could be a good idea.

Magic 8 Ball | 18 februari 2020

Please provide link to where somebody wrote it's ok.