Need help with A.C. issue

[tevake]

Hi, I spend a lot of time on the Porsche forum next door, but am having an issue with my 2002 530i. And hope someone here can thro some light on it.
When driving for more than a half hour I start to feel sleepy and then end up with a bit of a headache. seems like I am being gassed out.
There seem to be no exhaust leaks to be heard when blocking the tailpipe , While it is running. And I have replaced the fresh air filter.
So what is next in trying to sort this out??
Thanks Richard
PS I haven't been able to use the car since this developed, and would love to get back on the road with it.


I found the car via ebay a couple years ago in St Louis, then had epic road trip to the coast to ship it home to hawaii.

[JhwShark]

Sounds lik CO...can't smell it but it's there?? Try to look for gaps in the shifter area. Sometimes air can be drawn into the cabin through the shifter, there should be some foam or ather material to block inflow.

I doubt it has anything to do with AC.

I had a rent a car and got similar experience. Felt bad for the remainder of the day.