Why does my Bmw Serie 3 E90 smell burnt plastic ?

I’ve been dealing with a smell in the interior of my ’11 128i for over a year and a half. The smell has gotten so bad that I’m having health problems from driving the car — my throat feels like it’s on fire and my eyes are irritated and red if I drive with the the windows and sunroof closed — and even if the whole car is opened up. I’m at the point where I’m considering selling the car if I can’t get this issue fixed.

It all started when I had the VANOS bolt recall done. The valve cover and gasket did not seal properly and there was a small oil seepage that dripped on to the exhaust manifold. The odor of burning oil was sucked into the HVAC system and I immediately noticed the smell. The local dealer eventually got the valve cover and gasket to seal after two more tries and a new gasket. At this point I was still smelling a burning, irritating odor in the car. It seemed to be related to the oil seepage/burning issue but after several more trips to the dealer it was determined that the engine was properly sealed and no burning oil fumes were coming into the interior. It was suggested that I replace the cabin air filter so I did — with a seemingly temporary relief from the smell for a few months (it was winter now so the car was being driven in colder temps). The smell came back with a vengeance when spring came and was completely intolerable. Other people riding in the car noticed the smell, and reported it without my solicitation. I replaced the cabin filter again with no improvement.

I took the car back in May just before the CPO warranty expired. At this point, two service advisors, two mechanics, and the shop supervisor had claimed that they never smelled an odor inside the car during any of my previous 4 visits. I insisted that there was an odor and demanded further action. I was told that a «regional troubleshooter» would be coming by the dealership soon and would take a look at the car. A few weeks later this individual did in fact visit the dealer and investigate the issue with my car. I got a call from the trouble shooter and he reported that he immediately noticed an strong odor from the car’s HVAC system and the BMW would replace all equipment in the HVAC air flow path under the CPO warranty coverage. This work involved completely removing the dash and replacing the heater box, evaporator, drip tray, ducting, vent grills, and some other components that I can’t recall. Over 20 hours of labor were needed to complete the work.

Upon dismantling the HVAC the troubleshooter reported that a «strong odor was found in the heater box». So it appeared that some foreign material, possibly burnt oil residue from the valve cover gasket fiasco, or something else had contaminated the HVAC system. I never got an actual diagnosis of what was causing the smell, i.e., oil residue, mold, burnt plastic, etc.

Two months later in August I got my car back — with seemingly clean air blowing through the vents- but the smell was noticeable in the car the minute I opened the door. I brought the car back in because of the smell and also because when the AC was on during hard right hand turns water was dripping onto my right foot. So the dash came off again and it was discovered that a drip line was crushed (during the re-install) and not evacuating water. No cause for the continued smell was found. They gave me back the car and I brought it right back in again — the smell was still present and as strong as ever and water still dripped on my right foot during hard right hand turns when the AC was on.

They took another look at the car and then gave it back to me — saying that they could not determine the cause of the smell and couldn’t recreate the dripping water — even though I told them the exact off-ramp and speed where the dripping consistently took place. Sunroof and other drip pathways were blown out during this time with no blockage found.

I was told that BMW would no longer work on the car to try to fix the smell (major issue) or to investigate the drip (also a major issue). I was advised to call BMW «National» and given a phone number with the hope that «National» would authorize continued work on the car. I also took the car to an auto interior specialty shop and after a quick look they said they did not find evidence of long term water dripping into the carpet, so the water dripping is a «new» problem and probably not the cause of the smell.

At this point I am as furious as ever and reluctantly conceding that whatever this smell is may have long term health effects on me if I keep driving the car. I’m also not sure what the cause of the odor really is — were the oil fumes from the VANOS recall debacle the originating cause, or did some other issue come along at the same time? I have scoured the ‘net for similar cases and seen a few posts about insulating materials and adhesives creating fumes in the car — the «burnt crayon» smell that apparently affects some BMW’s and Mercedes. The smell seems to be strongest under the dash but it’s immediately noticeable as soon as I open the car.

As a last resort I’ve hired an environmental engineer who has conducted a «sniff test» on the car with some sort of sampling device that is used in his industry to determine air quality/composition for industrial and commercial environments. He advised me that not only can he determine if there are toxic levels of various chemicals in the car, but also that he can consult with an established database to «baseline» compare normal levels for various compounds «normal’ vehicles. I’m hoping that he finds something that I can take to BMW to get them to continue to work on the car. At this point I’m starting to think that the issue may be with the interior materials creating the odor.

Has anyone had a similar experience to me? I’m at my wits’ end and suffering when I drive my beloved 128i. I bought this car to take me all the way to my last days of driving a stick and looked forward to many more years of driving enjoyment. Thanks for any input you may be able to supply.