air vents, soot, dirt, noxious smells

mikec

Member
While taking out the G263 sensor I took out the foot vent (black plastic 'box') and had a look inside. It was quite dirty, with what appeared to be soot. Has anyone had very dirty vents before, and how did you clean them? I don't really want to pull the whole dash and air-conditioning/heater unit apart.

I am also at the beginning of the process of finding where a nasty smell is coming in from. It smells like exhaust/soot.. I have to fix the drains under the bonnet to make sure they are not open all the time (depends how far they are pulled onto the plastic? one isn't quite glued, and perhaps it's stretched on too far), and to make sure that the small one near in the firewall is there. I also want to check the exhaust vents/valves in the rear of the car. Is it possible to do this from the inside, by removing some trim perhaps, or does the bumper have to be taken off the car?

Could the evaporator or heater or anything else inside the hvac unit be dirty and causing this smell to persist even though not new pollutants are coming in from the outside? Can the evaporator unit be vacuumed? I plan on checking its drain hose and outlet to make sure it is clean and functional.

Can a biocide for the evaporator help with any sooty/exhaust smell, or would it only get rid of mouldy smells?

Is there any hope for the air inside to every really be clean? :) even when idling in traffic? :)

Thanks in advance for any help.
 
Check your webasto heater (if fitted) exhaust connection on the under tray is attached to the bottom elbow , this discharges to the underside of the tray when running.
Mine had been left disconnected floating around the engine bay!
Allowing exhaust gases to be sucked in through the air intake.
A/C cleaner can be beneficial for the mouldy odours & should take less than 10 mins to run through.

Also found moss in my air intake grille
On bonnet could also be black deposits source as bits were lodged in the drains keeping the open all the time.

Hope this is of some help.

Keith


Tapatalk
 
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No mention of the pollen (cabin) filter so if it has not been replaced recently, try fitting the 'carbon' version which helps minimise the smell of traffic fumes.

Cheers Spike
 
I've changed the pollen filter to a new MANN CUK 2545 (carbon type). It didn't seem to help. I will check if I even have a webasto heater, but I do remember an aluminum flexible hose going to the bottom engine cover (right hand side). This is my first diesel car, and when I heard about diesel heaters it seemed a bit strange to me! A lot of complication to get heat early! I saw that they changed to electric for the later models. Mine is a 2002 built in 2001. I have yet to check all of the codes on the label in the boot.

Do the A/C cleaners that you set on spray while running the ventilation on full with recirculate actually help for the long-term?

Thanks.
 
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No.

Carbon filter helps massively. The pre-heater concept is not just for diesels, it's very well known up here where temperatures get serious in the winter.

Check that under both front carpets is dry and that the boot is, too. Make sure the carpet itself is clean - you can take the front ones out relatively easily, but the rear requires removing the front seats (which is also not very difficult, just make sure the battery is off for 10 minutes before you disconnect the airbags).

The rear vents are underneath the bumper and require the bumper to be removed before you can get to them. Deal with the inside of the car first, making sure there's no old tea somewhere and that it's completely dry.

- Bret
 
Everything looks clean so far. I have not taken out the carpets, but there are and were no spills on them as far as I can tell.

I took apart the air inlet under the hood (breaking the plastic rivets), and inside there was something white, maybe it was mould? I cleaned out both sides. The drains, while relatively clean, do not close properly. Does this have a serious potential for letting noxious gasses in? I will glue them back onto the plastic. I am considering putting a small amount on cyanoacrylate glue (crazy glue) in the middle of each of the 'lips' to help them stay closed, leaving the sides for the water to come out of. It this were to work, perhaps a new pair would be in order.

The small water drain (on the air inlet by the firewall, inside the engine compartment) looked ok, the lips closed properly.

The smell inside the cabin might be musty. I think it's a mix of musty and dirty/sooty. When I was putting the G263 sensor back in, the the inside of the left foot vent outlet on the main hvac unit did not appear to be dirty inside, so I wonder how come the plastic outlet vent that attaches to it was, when I took it out yesterday.

Anyway, I might take out the right hand side lower A pillar trim, and have a look at the evaporator drain next.

With the G263 reinstalled, I tried the A/C, however it still did not seem to blow very cold air (it was ~15degC ambient). No faults were recorded, and Measuring Block 7, Display Zone 3 (Value measured by the evaporator outlet temperature sender G263 in degC), showed close to ambient, even when I set the Klimatronik panel to LO. In Measuring Block 1, Current through N280 (A/C Compressor Regulating Valve) was measured at ~0.65A, Signal Ratio for N280 was ~55%, Signal Ratio for G65 (High Pressure Sender) was ~19%, Absolute Pressure was ~4.4-4.8bar. From what I could tell, G263 temp should be much lower than ambient, and close to 0degC with Klimatronik set to LO, unless the there are high ambient temps (i.e. system overworked).
Does this mean that the refrigerant in the system low? Could it mean that the compressor is having problems providing enough pressure? With N280 at ~0.65A, I do not understand when the pressure was only ~4.5bar. I bought the car in late 2014, and it appeared that the A/C worked, though I don't recall very well, and the weather didn't lend itself to checking easily. I do not know if and/or when it was topped-up, however it has not been topped-up since.

Do biocide A/C cleaners (sprayed on/near evaporator) help for the longer term?

By the way, it looks like this car has a diesel heater, however, I cannot connect to it (Controller 18 - Auxiliary Heater). The fuse (30A) was found to the blow in the recent past, and I replaced it. It seemed like the car warmed up faster than usual, but not very fast. I wonder if the heater could use some maintenance...


Thanks for the help so far.
 
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Try getting an aircon refill anyway. Should be around €50 or so. The system pressure should be over 5bar.

You already went through a re-learn of the flaps? I would also make sure your flaps are moving correctly, because they probably don't.

You could also consider swapping out the climate dryer while you're at it, that may well help any smell issues.

- Bret
 
I did the Output Tests, but not Basic Settings. When the car ignition is turned on, even with the Klimatronik panel off, I can hear noises that sound like motors whirring, flaps moving, and some slight knocking (closing/opening of flaps? or maybe something overturning, skipping and hitting plastic?)

I checked the evaporator drain and it was very clean... like, never used? :) The flap didn't stay totally closed, there was about a 1mm gap at the point farthest from the hinge. I washed it, dryed it, and put it back in. I looked under the floor panel, and there was a hole seal loose. It was inside there, though a bit dirty. The seal seems to have broken with age, and does not want to stay in the hole. There are two, and it seems like there is some sort of glue/sealant on them, so perhaps they were glued in. The one that fell out covered a hole that was not on a totally flat piece of aluminum, so perhaps that's why.

What is the climate dryer?

I can hear a slight groan/hiss when the Klimatronik panel is not on ECON (i.e. A/C compress on). When car is shut off, the hissing slowly stops. Is this normal, or does it indicate an issue with the compressor?

I wanted to take out the blower and clean it, but after seeing the access to the screws holding it, I started having second thoughts. :)
 
do the basic setting and see what happens. Should be as simple as entering 001 and hitting go.

That will cycle all the flaps through their paces.

When you turn the ignition on, the recirculation flap will be opened again, so it's normal that there is whirring.

The climate dryer is a small tin can at the front of the car... on the left side in the direction of travel. It should be replaced regularly, apparently, though I know of no-one that does it as it requires the climate system to be emptied first. This one: http://www.ebay.de/itm/Klimaleitung...-Audi-A2-8Z-/180931358825?hash=item2a20597069

- Bret
 
Glued the main drains in the middle, leaving two small areas to each side. Using a shower handle, I sprayed water into the air intake (where it comes in from the outside). After not very long it overflowed into the air intake outlet (where it goes to the car). So I had to cut them apart. I might try again maybe making the dot smaller, but I doubt it will work.

Could oil around the EGR area cause fumes to get inside, if the drains are all ok?

I would like to clean the EGR, but don't have a torque wrench. Are the torques on the pipe from the exhaust important?

How does the a/c system dryer affect anything inside of the car? Maybe I don't understand how it works.
 
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Air is pulled in from the top of the bonnet and goes directly to the air filter. From there into the blower.
The blower mixes heat via the heat exchanger and cold air from the climate compression system using flaps. The flaps also control the direction of the air - up, down, from outside directly (via filter) or recirc.
The only possible thing that could seriously affect the climate performance apart from too little climate gas is the dryer, because it's the bit where the gas is sent to have its water condensed. If it's been too moist / something is growing, then it's there. I've looked up some of this stuff today on the German forum, because we've been through most of this in detail, and that's the only part of the system where there's any evidence of possible bacterial growth. There are claims for better smell after "antibacterial cleaning", but to be honest, if the interior smelling, it shouldn't be the Aircon itself that is the cause.

You have also checked the drain pipe from the blower, the one that exits just in front of the firewall on the right-hand side in the direction of travel? That one ends below the glovebox in an LHD car and then goes outside. It's possible it's bunged up and / or dirty.

The drains on the bonnet should be completely immaterial.

Is this an oSS car? If it is, the roof drains may also be a problem.

The EGR should have a gasket on it, and if you want to clean it, do so. As for torque, I'd personally err towards "tight". ErWin can tell you the full details if you need them.
The opinion on the German forum for exhaust fumes in the cabin is simple: there's either a pipe not on the air filter correctly, or the EGR has some kind of issue, normally because of a loose or broken pipe. Depends on the model exactly what the issue may be. For petrols it generally involves the throttle body, for diesels I'm not sure, it doesn't tend to show up.
Try maybe running the car when it's cooler and the car is warmed up, take the bonnet off and watch / smell for signs of fumes? It should be pretty obvious.

- Bret
 
You need to dig deeper , the dryer is in the refrigerant line & never comes into contact with the air side, if you are getting fumes/ exhaust smells the most likely culprit is the webasto system.

The drain boots are meant to open to allow excess water out but wouldn't be gas tight even when new.

The a/c compressor may be of a variable type that will only cool to a predetermined level relative to outside air temperature, I will have to check my late 2001 1.4 tdi 75hp tomorrow & see.

Cheers
Keith.


Tapatalk
 
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No opensky.

i checked:
bonnet drains; did not appear very dirty, don't close very well; cleaned
small drain near intake by firewall (similar to those on bonnet, but smaller); did not appear very dirty, seemed to close well (checked when off the car); cleaned
evaporator drain pipe and valve; was very clean, drain valve did not close fully; cleaned anyway

I also took apart the intake under the bonnet. I wouldn't trust the perimeter seal and the one in the middle sealing perfectly properly after this, but that might be insignificant.

There is some dark oily stuff near the EGR (oil/fuel mixture?). I haven't cleaned it off. I wanted to take off the EGR to have a good look, and to see where the leak might be coming from. Perhaps the turbo is leaking slightly? When I disconnected the pipes at the bottom of the intercooler in the recent past to see if there was any oil pooled there, there were some droplets that came out, but not very many.

During all of this bonnet/drain/G263 work, I started the car with the bonnet off, and it didn't seem to smell inside at first. It started after some time of idling (EGR heated up and seals loosened? Exhaust fumes from around the car got into intake?). The smell was not really an exhaust smell I think, more like oil/fuel mixture maybe... though I'm still new to the various smells of things on diesel cars. It seemed to be more with recirc on than off, and perhaps heat on than off... Not sure though; maybe I'll check more carefully. The heat exchanger is horizontal, and I figure was used more than the evaporator (the interior needed to be heated more often than cooled), so is it possible that any pollution that got past the filter got stuck on it, and now it smells? I also put my hand into the foot vents that come out near the floor near the gear knob, and though they were not very dirty from either side, when i reached in further on the bottom (horizontal) of the tunnel that goes to the rear floor vents, there was this black sooty kind of dirt. So again, maybe all of this stuff settled on horizontal surfaces in the system, if/when it got past the air filter?

By the way, the various trim pieces with sound proofing the back, have a somewhat bad smell in places. E.g., behind the glove box, side panels of centre console (especially near vent outlet, and near the front where the trim goes up towards the dash.. interestingly around where the hvac system is... and more vents!)

Doesn't the webasto system only operate when it's cold outside? It was 15C and then 12.5C today, so if that is the case, then it should not have been running. Can there be leaks from it even though it's off?

As to ducting.. Doesn't the fresh air (from outside) go to the blower first, and then through the filter? That's what I figured from diagrams of the system.
http://workshop-manuals.com/audi/a2...ducts/air_duct_in_heater/_in_air_conditioner/

This to me is starting to sound more and more like an issue cause by a leak somewhere inside the engine compartment (poor a/c functioning notwithstanding), and maybe some residual stuff inside the ventilation system (especially heat exchanger).
 
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Also, there's a lot of clicking going on (with the vents I think)!!! Even with off, whirring yes, but then clicking, clicking, clicking, and after a minute or so it dies down. I wonder what's being done to the vents.

Going through the Output Tests, I think every vent made a clicking noise during part of its test, except for the defroster vent! Old car? :)
 
By the way, the plastic trim from the glove box, on the inside, was quite dirty. Driver's side trim under the steering wheel wasn't great either. Interestingly, lower A pillar trims, from the insides, also had black dirt.!

There is A LOT of pollution in Poland, especially where I am perhaps. For some reason, people heat their houses with not only wood (maybe not so terrible), but still coal, and some unfortunately with garbage)! Some cars and trucks and busses also pollute a lot. Some trucks and busses spew tons of black smoke. Are there no emissions controls in this country? At least for trucks/busses? If there are, I wouldn't be surprised if some people cheat the system somehow. I have heard of cheating happening at the yearly safety inspections...

Sigh (of very relatively fresh air [at the moment! :)])
 
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air con is "off" so the clutch is engaged and the compressor does not run below 5C or so.
It's also possible that there has been a leak at some point in the past and it has been fixed, but bacteria grew and they weren't cleaned properly. So I'd consider a complete stripdown at some point when the weather's going to be good.

The webasto should not be running over 7C or so, but I think you can push it for testing. Yes, it could smell, but then it would be fuel, because it's burning diesel.

It does seem that there's lots of dark dust in the car; did someone drive lots with the windows open? Maybe.

- Bret
 
If it smelled inside, I wouldn't doubt it. I sometimes open the windows myself to air it out, or because it's nice outside.

Anyway, I took out the EGR, and while it wasn't very blocked inside, there was some .. oil/fuel? .. on the outside. My guess is that the seals inside the actual unit might be worn, and weeping oil/fuel mixture (especially bad because it's pressurized air?). I will probably try a new exhaust intake gasket (I didn't see one when I took the unit off), and also a new seal between the unit and the intake manifold (old one is totally flattened), and cleaning up the inlet pipe and re-seating it. I'm not sure how much that will help though. If the seals inside the unit are worn then I don't know what else can be done other than replacing the unit. I saw a Wahler (same brand as the one I took off the car), available online for ~160 euro (with VAT). I would rather it be something else, like the replaceable seal/gasket :) , but we'll see. I might also take off the underside engine cover, and try to see if I can locate any other leaks. By the way, even though the exhaust intake gasket was missing, there was no sign of exhaust (It would look black/sooty if exhaust was leaking due to lack of gasket, I presume).

So for now, car is non-operational, and I'm trying to sort out leaks/oil in the engine compartment.
 
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