问:气味来自A / C通风口

在我的车,有一个气味通过A / C系统的通风口。有水箱漏水,但更换。“有”是一个气味的来源,但现在是一个2日真的让我头痛。有时,气味相当金属和热废气。然而,它还热液的味道类似于动力转向液或防冻。经销商做了压力测试冷却系统和报告给我,它不是一个加热器核心泄漏。我取代了新鲜空气过滤器。在过滤器,我想有一个差距,泄漏,但他们看起来不错。气味只是从驾驶座a / c通风口。当空气流在低,气味更明显。 I crack the window or open the sunroof. I had also thought that it might be the exhaust back-drafting into the car. The dealer has not helped me one bit, despite the expense! Can you give me suggestions on the cause of this problem and how do I solve it?