bencho4wd

hi, i'm from malaysia. i owned a Q7 3.6 v6, year 2008. i encountered an issue that after hard acceleration, some odor that smell like "hair dye" will intrude into the cabin. i reckon that it should be from engine bay (probably metal burning smell). i have run through some diagnosis as below :

1. when i switch " air-cond recirculation" to recirculating mode, the smell will presence in the cabin after hard acceleration, with the situation that the car is moving 70kmh and above.

2. when i switch " air-cond recirculation" to fresh air mode, no matter how hard or how fast you drive, the smell will not presence inside the cabin.

local mechanic told me the possibility of the issue as below:

1. rear bumper will act like a scope and when car is moving on certain speed, and air-cond switched to "recirculating mode", outside pressure are greater than cabin and hot air that flow through engine bay will scoped and press in via rear hatch door.

2. when air-cond is on "fresh air mode", basically air pressure will be building up inside the cabin (cabin pressure greater than atmosphere), hot air from engine bay will scoped too but unable to forced into the cabin due to cabin pressure are greater than scoped air pressure.

above are explanation from the mechanic. anyone here have similar issue on Q7?

thanks.

ben

chickdr

I am betting you are experiencing the musty smell many of have had in our Q7's. I used Einszett 961105 Klima Cleaner which cleared the smell up. It will recur due to bacteria growing in the system. Poor design. Try this and see if it helps!

bencho4wd

hi chickdr, thanks for your advice. as far as i noticed, the odor did not persist in the cabin. it just happened only during hard acceleration with "air-cond recirculating" mode is on and drive above certain speed. The odor won't appear unless you drive hard.

Giblet

I am also experiencing a similar smell after coming to a stop after a hard brake or accelerating from a stop. The smell is intermittent - happens once or twice a day and takes about 5-10 seconds to clear up.

I thought it may be related to an oil leak I had above the manifold (i.e. fumes of the oil burning as it dripped) but that was fully repaired and it still persists. I also wonder if it maybe rotting debris but don't understand the intermittent behavior then.

Any ideas to help direct the technician the next time I take it in? I am due for a new cabin filter but somehow think this may be more than that.

va-terps4

Assuming your issue is the bacteria/mold issue, I've seen general maintenance recommendations for putting the windows down, and letting the car idle for 20-30 minutes with the heat turned up all the way and the fans on full speed. This should dry out the moisture in the system, as well as run the temperatures up high enough to kill the gunk growing on the AC coils and heater core.

But your hair spray smell sounds like it could also be a radiator or AC refrigerant leak.

bencho4wd

hi giblet, did you replace your tail lamps to newer design? i have resolved mine as mine are pre-facelift model, and i have replaced it with new facelift tail lamps (exterior looks identical but the black colour dust seal has different sizes). newer tail lamp has smaller dust seal hence leave a small opening and the air from exhaust can flow into cabin.

1. new facelift lamp < http://cars245.com/PICS/MM/optics/au...1+LLH182_2.JPG >
2. old facelift lamp < http://thumbs2.ebaystatic.com/d/l225...f2gk6ssOig.jpg >

Giblet

bencho4wd,

I do love the look of the new tails but at this point, I am holding out for the new redesigned Q7 and will either bite on the 2nd gen Q7 or look for a 1st Gen TDI Q7.

So, no modding yet until I determine if I just jump into a whole new one.