Burning smell coming from passenger wheel well!!!????

[19birel]

So lately I've noticed a burning smell accompanied my a wisp of smoke coming from the front of my car when I go to park it. Last night I came back and there was quite a bit more smoke than usual (possibly because of all the snow), enough that I could, with the help of scent, trace the source, the passenger side wheel arch. What do you guys think this could be? I initially assumed brakes, especially because I recently replaced the lines in the front, but wouldn't the car pull to the right if the passenger caliper was stuck? I just drove it another mile or two with frequent stops and felt the brakes with my hands and both seemed to be the same temp, but I could still faintly smell the scent in the wheel arch. I also checked to see if my tires were rubbing but that doesn't appear to be the case, the only other thing I could think of is that maybe the wheel bearing is going bad? But even my driver's side rear bearing that occasionally makes noise doesn't smell like that so I have no I'm out of ideas.

And if you're wondering, yes, I sniffed out the entire engine bay, and zero smells. it's definitely coming from the wheel arch.

Things I'm planning to check that I missed at first

- plastic fender liner towards back side of arch

- Brake Fluid level

-Oil Level (just replaced vc gasket, though if I had a leak from there I'd smell it in the engine bay, ill still check anyways)

Any and all help is appreciated, I have found a number of threads covering this, all inconclusive so hopefully this will finally be the one with some answers!

[19birel]

So I have a little more info and another question. So someone from the B8 forum suggested that it may be something with my foglight as they had a similar issue. So I drove 5 or 6miles, this time with the fog lights off (I always drive with them on a night because my headlights suck), and parked the car. This time I saw a small puff of smoke again (less than last time) and went out to sniff around, this time I smelled nothing.

My guess is if there was no smell but still smoke, then the smoke is unrelated, probably the snow just touching a warm part of the car (I parked the car in one lot after a few miles and no smoke, drove about a mile or so and parked in a different lot with a decent but of snow and saw smoke). I'm also guessing that the burning smell could possibly be by fog light or the wiring, I also remembered that my headlight washers are disconnected, my painter forgot to plug them back in and I didn't bother to reconnect them because I didn't want to accidentally trigger the washers when the caps were frozen and damage something in the cold winter temps. Are these on the same circuit as the fogs? I need to find a wiring or fuse diagram, but if they are, correct me if I'm wrong but that may be the issue?

Any and all insight appreciated, thanks!

EDIT: Headlight washers are not on the same fuse as fog lights, so it doesn't look like the washers being disconnected could have any effect on the fog lights.

[bmos]

You'd probably hear it if it were a wheel bearing and your wheels would be pretty warm in the center cap area.

If it's brake drag then you would feel a heat difference and it would pull when driving (but not when braking).

[CarlWeasly]

Interesting conundrum you have here birel The only thing that i can think of off the top of my head is ,IIRC, there is some evap stuff inside the passenger wheel arch, hidden by the splash guard. It may be possible that could be causing your smoke, but I'm not totally sure... or it could be possible that you're rubbing? again I'm just spitballing here, hopefully you can get it figured out though!

[19birel]

You'd probably hear it if it were a wheel bearing and your wheels would be pretty warm in the center cap area.

If it's brake drag then you would feel a heat difference and it would pull when driving (but not when braking).

That what I figured, the car drives fine thankfully so I don't think it's mechanical.

Interesting conundrum you have here birel The only thing that i can think of off the top of my head is ,IIRC, there is some evap stuff inside the passenger wheel arch, hidden by the splash guard. It may be possible that could be causing your smoke, but I'm not totally sure... or it could be possible that you're rubbing? again I'm just spitballing here, hopefully you can get it figured out though!

Maybe it's Evap related, but the smoke isn't consistent so I'm not terrible worried. It's the darn smell that has be concerned. The wheel isn't rubbing, and after driving the same distance with my fogs off the smell wasn't there. I think I have an electrical issue, is it normal for the fogs to burn really hot before they die?

[CarlWeasly]

To be honest i'm not certain, but i dont think they do, they would just "die" like a regular bulb i would think. Do you have a CEL? Might be worth a vcds check if you have access to one

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[Spectre1130]

A shot in the dark but make sure your heat shielding didn't catch on fire. They made some with a "flame retardant" fabric inside and when oil leaks onto it it becomes very flammable.

I have a C5 A6 with the 2.7t motor and had just replaced my downpipes with aftermarket ones. When I was driving it cross country I had something similar happen and when I looked underneath I had it smoldering, and eventually had flames coming off of it.

[19birel]

To be honest i'm not certain, but i dont think they do, they would just "die" like a regular bulb i would think. Do you have a CEL? Might be worth a vcds check if you have access to one

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No CEL, I have a VAG-com scanner though so I'll check for codes.

A shot in the dark but make sure your heat shielding didn't catch on fire. They made some with a "flame retardant" fabric inside and when oil leaks onto it it becomes very flammable.

I have a C5 A6 with the 2.7t motor and had just replaced my downpipes with aftermarket ones. When I was driving it cross country I had something similar happen and when I looked underneath I had it smoldering, and eventually had flames coming off of it.

I actually got a new downpipe installed recently, I'll check the heat shield, but considering I drove almost 1k since installing that and changing my valve cover gasket I'm not sure. I'll give it a look though, thanks!

[biketsai]

See any oil spots underneath? Could even be something like a torn CV boot that flung grease onto the exhaust.

[Rodgman15]

I've experienced something to that effect before. O ring on the rear coolant flange gave out and coolant was running down the side of the trans, and squirting out onto the down pipe. Every time I came to a stop light a puff of smoke would roll out.

[SN95Audi87]

I've experienced something to that effect before. O ring on the rear coolant flange gave out and coolant was running down the side of the trans, and squirting out onto the down pipe. Every time I came to a stop light a puff of smoke would roll out.

This happened to me back in the day of early ownership of my car. The coolant would leak behind the head and puff smoke. It wouldn't smell like burning oil though but more sweet scent.


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[19birel]

See any oil spots underneath? Could even be something like a torn CV boot that flung grease onto the exhaust.

No oilspots underneath, I also check the CV boots <1k miles ago when I did the front control arms and they looked good.

I've experienced something to that effect before. O ring on the rear coolant flange gave out and coolant was running down the side of the trans, and squirting out onto the down pipe. Every time I came to a stop light a puff of smoke would roll out.

This happened to me back in the day of early ownership of my car. The coolant would leak behind the head and puff smoke. It wouldn't smell like burning oil though but more sweet scent.


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I'll check that out. The smell is something to do with the passenger side foglight, I drove around last night with the fogs off an no smell, but still a tiny bit of smoke (though I hardly noticed it). I'll check that o-ring out though, did just replace it when I installed my rebuilt head, but what you guys are saying sounds very plausible so I'll take a look at it.

[Spectre1130]

I actually got a new downpipe installed recently, I'll check the heat shield, but considering I drove almost 1k since installing that and changing my valve cover gasket I'm not sure. I'll give it a look though, thanks!

I had installed mine a long time before they caught fire. I guess it just decided to soak up enough oil. I know it was a common problem on the A6 2.7t's, but have not really heard of it on the A4 1.8t's. But its possible.

[ricekikr]

This happened to me back in the day of early ownership of my car. The coolant would leak behind the head and puff smoke. It wouldn't smell like burning oil though but more sweet scent.


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Also happened to me. Both the back of head and the coolant return of turbo on the front passenger side of the block under the manifold.

The turbo return is a bit hard to access.


Also check your power steering fluid, if rack or hoses (even if in driver side) it'l crawl to center and drip on the exhaust and cause a bit of smoke.

[19birel]

So I checked the coolant flange on the back of the head an it's bone dry, and the coolant level hasn't changed since I last checked it. It smoked again, and I looked under the car and saw some from the what looked to be near the exhaust (downpipe area) I don't think it's leaking, but something could definitely be dripping on it. I topped off my ps fluid before I left home, so I'll see if the levels have changed, definitely seems plausible. Good idea!

[19birel]

Fluid level was low, and there's moisture around this pipe, so either that's cracked, the reservoir is cracked, or both.

My question is how does that migrate to the exhaust?


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[ricekikr]

Check the ps hoses at the rack. Also check the rack itself. The one on the reservoir isnt the culprit. Unless your 2.8 and the driver side is smoking.

Check the heatshield above the downpipe, if its wet, get a rag and dab on it, check color of fluid. Greenish yellow = oem/chf7.1 ps fluid

If you just went for a drive and ps fluid was low again, you should have fluid on the ground unless it all drips on the exhaust and burns up.

[19birel]

Check the ps hoses at the rack. Also check the rack itself. The one on the reservoir isnt the culprit. Unless your 2.8 and the driver side is smoking.

Check the heatshield above the downpipe, if its wet, get a rag and dab on it, check color of fluid. Greenish yellow = oem/chf7.1 ps fluid

If you just went for a drive and ps fluid was low again, you should have fluid on the ground unless it all drips on the exhaust and burns up.

I'll check the rack out, and the heat shield. I'm 1.8T and the origin is closer to the passenger side, so it makes sense that the resevoir isn't the culprit, though the moisture around the hose looks suspicious. I haven't topped up the fluid since I was last home (about a month) so it can't be a huge leak, but I also have only driven about 400 miles in that time as well...

Thanks again, will report back once I check that out

[ricekikr]

Check the rack boot specifically. Pass side. It gets filled up with oil and drips, it is direclty above the downpipe.

Depending on your leak it could be just slightly moist to very muddy/sludge like.

[19birel]

Went on a drive (~30miles or so) and when I parked smoked poured out from the wheel arch and there was a strong burning smell. Popped the hood and puffs of smoke occasionally would come out of the area pictured above. This steering rack theory is making sense as the smoke source seems to be something burning on the exhaust,but I had trouble getting a good view. Any suggestions as to how I can get a good look to confirm this?


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[CarlWeasly]

If you have rhino ramps, putting the car on those should let you get a look at the underside of the bay quickly. Taking off the passenger wheel should let you get another angle of vision to check things over with the dump pipe and steering rack

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[Rodgman15]

I'm still leaning toward coolant from the flange getting into the downpipe. I've also got a leaking steering rack but the fluid never makes it past the end of the boots. Hope you find the issue!

[19birel]

If you have rhino ramps, putting the car on those should let you get a look at the underside of the bay quickly. Taking off the passenger wheel should let you get another angle of vision to check things over with the dump pipe and steering rack

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That's what I feared, unfortunately I don't have any ramps or a jack stand here at school with me.

Do you think my steering rack needs replaced? because that's what this is beginning to sound like...

[CarlWeasly]

That's what I feared, unfortunately I don't have any ramps or a jack stand here at school with me.

Do you think my steering rack needs replaced? because that's what this is beginning to sound like...

That sucks. I wouldn't say a new rack just yet, the rack itself should be fine I would think. could be the boots or possibly a loose line, don't know for certain obviously,

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[19birel]

That sucks. I wouldn't say a new rack just yet, the rack itself should be fine I would think. could be the boots or possibly a loose line, don't know for certain obviously,

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I'm slowly leaking fluid somewhere, so I'm guessing there's a perished seal somewhere in the rack. When I go home in a few weeks i'll jack it up and see. Hopefully it' just a cracked hose or line. I just watched a brief diy on what's involved in removing the rack and it's not fun. I guess I'll just wait until I go home in a few weeks to investigate more. Fingers crossed haha

[ricekikr]

Jack, remove passenger wheel, remove the small wheel well cover for the steering rack (1 nut and 2 clips), see if steering rack is leaking.

If it is the passenger side thats leaking, boot must've come off. Reinstall boot it'l prevent the smoking but not the leak (wont drip on the downpipe but still lose ps fluid)

Another test would be to drive until downpipe is hot then turn steering wheel stop to stop, don't keep it at stop just bump it then turn back, like when your reversing for a parking slot. Depending on leak it, it could smoke in as little as two turns.