I fixed my plenum thinking that it would also fix my a/c problems but it is still messed up. When I turn the a/c on it comes out the vents okay but it also comes out the floor vents. Doesn't matter if it is on panel only or max a/c. If I go down the road it does it until I let off the gas a little then it blows hard out of the vents, but as soon as I go to pass or accelerate for any reason it comes out the floor only and gradually goes back to the panel vents. Is this a vacuum issue or maybe something else. Where should I start to look as far as vacuum lines. All the ones I have checked so far have looked fine.

 

Do a search for wild vents, lots of info for a fairly common problem.

 

Thank you. I did the search and think I have found my problem. I need to replace both of the cv's and pcv. Thanks again. I never would have thought to search wild or wacky vents. I was searching a/c problems and couldn't find a thing.

 

Be sure and let us know if the check valves fix the problem. Get them and the PCV from the dealer only. And replace the cv's first, this way we/you will know which item was the problem. I doubt its the pcv.

 

I doubt it's the pcv as well but I'm going to replace it along with the rest just because it is looks like the original and they are cheap enough.

 

I finally found the other cv, the one coming off the tee fitting. It tested good so I called the dealership here and he said that they have 2 in stock for $9.99/each. I will go up there when my wife gets off work and report back tonight to let you know if it works or not.

 

No luck. Still have a mix of floor and panel vents, floor and def. I thought with a vacuum leak it would default to defroster only.

 

Loss of vacuum it should indeed default to defrost. If you vents are doing something other than that, need to explore for leaks in the dash......

 

I don't quite follow. Do you mean in the vacuum lines on the inside or something else? I forgot to mention before anyone says it, I already disconnected and plugged the 45° angle going to the cc module. How hard is it to smoke a system or is that something that I should have done at the dealership?

 

There is a snakes nest of vacuum lines running around the dash to the various little pots that open/close various doors. I suspect you have a leak in that vacuum harness somewhere, or even the control itself.

If you have one of the hand vacuum pumps, could try testing each circuit individually, and see how quickly vacuum bleeds off? A visual inspection would more than likely require taking out the dash...... no fun at all.