I have a weird issue with my vents and was wondering if this is the issue causing it. when I have the A/c on and going down a rough road my venting turns off but sounds like it is blowing out the defroster vents.. does it for about 20-30 secs and then comes back out the regular vents.

 

you have a vac leak.

 

a leak where these guys are talking about the check valves being.. in those lines? I haven't looked at a diagram to see what all consists of the system so just trying to get an idea.

 

Your vac leak could be anywhere along the accessory tree bracket lines, you just have to check and test to find it. Anything that hooks into the accessory tree could be guilty.

 

i know i have a leak somewhere. i noticed earlier that while cruising at about 60 and 1700 rpms air comes through the vents with them off, then a slight increase in throttle makes the air stop, then when i let off the gas at the top of the hill i feel a stronger burst of air. the burst is about 1/4 as strong as when the switch is on low on face/feet.

what are the two canisters under the dash with the red and yellow vac lines on them for? i'm thinking that they have something to do with my issue (actuator doors maybe) but i may be wrong, i've never chased down a vac leak before.

 

I found a bad check valve. Its the first valve leaving the intake manifold on the passenger side. Or at least I think its a bad check valve. Looks like a check valve but doesn't "check" anything. Replaced it and will see what happens.

 

honestly,

Vac leaks can be a nightmare to track down. Your best bet is to go to a shop with a smoke machine that will send smoke thru the vac system and identify the spot of the leak.

You can also try to cap off and isolate each system from the tree and see which one improves the condition, just don't take off the big one that goes to the brake booster or you'll be hating life.

 

Found my bad check valve. It was the one thats right off the intake manifold.

 

well i'm pretty sure i found it. and i'm starting to think that the guy that did my transmission is absent minded. he used a rubber seal instead of the oem rubber/plastic one that i wanted on there (i even had a new one in the back seat). he had the transmission bolts too loose, it took a little over a half a turn to get them all to 13 ft lbs.

and he left this on top of the heat shield over the cat:


but i found out where it goes when i stuck my camera above the transfer case:


now i want to drive it to see if the vents will work right but i need to get the front end back together before i can.

do you think it would have any ill effects not having the vent or the vac lines on the transfer case for about 1000 miles? and do you think i could get away with strangling that guy?

 

No.

Wear a puffy coat and thick gloves so you don't leave personally identifiable marks, then burn the cloths after you're done. Do it in a bathroom so there's so much random DNA they can't pin it on you and no cameras. Put a chunk of Dry ice near his liver to confuse TOD, but not directly on his skin as to avoid freezer burn marks. When it melts it will evaporate into nothing but CO2.