Intake vacuum related noise
07-08-2013, 03:01 PM
#16
Rennlist Member
disconnect the black supply line - you can cap it if you want. Plug where it connected to the four or three way. Drive it.
If the problem goes away you know it is inside the car.
If the problem goes away you know it is inside the car.
07-08-2013, 03:07 PM
#17
Rennlist Member
If the HVAC supply line is disconnected plug the valve.
With no vacuum to the HVAC all valves will go to there base state.......some are open some closed but no matter you wont have valves intermittently opening/closing.......if this is the case then your getting close to resolution.
Let us know.
With no vacuum to the HVAC all valves will go to there base state.......some are open some closed but no matter you wont have valves intermittently opening/closing.......if this is the case then your getting close to resolution.
Let us know.
07-20-2013, 03:26 PM
#19
Rennlist Member
Thread Starter
OK, looking at Wally Plumley's HVAC write up , the black hose that vanishes throught he firewall is confirmed at the HVAC feed.
Also checked out Waynes brilliant step by step HVAC refurb. Many thanks to both these people !
So black hose held vacuum provided by a Mityvac , but when I switched on the ignition it vanished and it wasn't possible to pump it up again. So the problem was a big vac leak to one of the actuators, and the clacking sound was as idle vacuum rose at foot off, the various flaps were reactivated, and then deactivated when the foot went on the gas and the vacuum dropped...
I went into the side of the cetre consul, (drivers side) and started cutting the vac feed from the solenoid assembly to the actuators, and found the centre comb actuator (blue vac pipe) was the problem - huge leak.
As I don't have time at present to remove the center console, I capped the cut hose from the solenoid, then checked the system for leaks, it was OK. I then reconnected the system but also tee'd the Mityvac off the HVAC vacuum feed (the supply buffered by the egg box vacuum reservoir) and drove the car.
The vacuum rose steadily to 22inHg and stayed there, just slight kicks down if I selected different slider positions. As the cruise control is non op I couldn't see what that did to the reservoir vacuum when activated. That's my next task while the side cover is off :-)
Many thanks to all those who responded to my questions.
Also checked out Waynes brilliant step by step HVAC refurb. Many thanks to both these people !
So black hose held vacuum provided by a Mityvac , but when I switched on the ignition it vanished and it wasn't possible to pump it up again. So the problem was a big vac leak to one of the actuators, and the clacking sound was as idle vacuum rose at foot off, the various flaps were reactivated, and then deactivated when the foot went on the gas and the vacuum dropped...
I went into the side of the cetre consul, (drivers side) and started cutting the vac feed from the solenoid assembly to the actuators, and found the centre comb actuator (blue vac pipe) was the problem - huge leak.
As I don't have time at present to remove the center console, I capped the cut hose from the solenoid, then checked the system for leaks, it was OK. I then reconnected the system but also tee'd the Mityvac off the HVAC vacuum feed (the supply buffered by the egg box vacuum reservoir) and drove the car.
The vacuum rose steadily to 22inHg and stayed there, just slight kicks down if I selected different slider positions. As the cruise control is non op I couldn't see what that did to the reservoir vacuum when activated. That's my next task while the side cover is off :-)
Many thanks to all those who responded to my questions.