Possible vacuum leak
2 issues that seem vacuum related:
The first is a sound and vibration I get while driving forward. While the wheels are moving, it sounds just like a baseball card in bike spokes, it usually happens after I backed out of a parking spot and put it back into drive. I will get that sound and vibration until I slow down, and just as I begin to stop, I feel and hear a big bump and the sound goes away.
The second is the old school **** climate control settings. The settings switch without moving the *****. Sometimes while I have the AC running through the dash vents it will switch to the defrost setting and then back to AC after a couple minutes. Sometimes it won't stay in the defrost setting and switches to the vents.
Any ideas on how to diagnose?
Last edited by Twonky; Apr 28, 2017 at 12:05 PM. Reason: make it clearer to understand
Use a Might Vac pump to diagnose.
Or, just cap off the vacuum line that goes to the PVH solenoid (they tend to leak when the housing cracks) to isolate it from the vacuum distribution system and see if the HVAC controls behave themselves. Also check the vacuum line that runs near the battery and through the firewall. They tend to get brittle and crack particularly in that location.









